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QUESTION: 1The Company WAN is displayed in the following diagram:

Traffic from Company4 to the Company Corporate Network is distributed between thelinks with unequal costs in the EIGRP network by configuring the variance command onCompany4 to 2. How many paths will participate in the load sharing?

A. 1B. 2C. 3D. 4E. 5F. 6

Answer: B

Explanation:If a path is not a feasible successor, the path is not used in load balancing. In this case theFD is 10, which means that only the paths with a total distance of 20 or less will bechosen. This leaves us only the paths from Company4-Company5-Company6 andCompany4-Company7-Company8.

Reference:CCNP Self-Study CCNP BSCI Exam certification guide p.485

QUESTION: 2Five Company routers are connected together as shown in the diagram below: Exhibit:

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2 http://www.hotcerts.com

You work as a network engineer at Company.com. You study the exhibit carefully.Company1 and Company2 are summarizing the 10.0.0.0/8 network and advertising it to allrouters. Which two EIGRP configurations will prevent unnecessary EIGRP updates frombeing sent and possibly causing 10.0.0.0/8 from being SIA on router Company1 orCompany2? (Select two)

A. Configure Company3, Company4, and Company5 as EIGRP stub routers.B. Configure an ACL on the interface of Company1 and Company2.C. Configure Company1 and Company2 as EIGRP stub routers.D. Configure summary routes on Company1 and Company2E. Configure static routing on Company3, Company4, and Company5

Answer: A, D

Explanation:A dual-homed remote will have two or more distribution (hub) routers. However, theprinciples of stub routing are the same as they are with a hub and spoke topology.

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It is not desirable for traffic from distribution router 2 to travel through any remote routerin order to reach network 10.3.1.0/24. If the links are sized to handle the load, it would beacceptable to use one of the backup routes. However, most networks of this type haveremote routers located at remote offices with relatively slow links. This problem can beprevented if proper summarization is configured on the distribution router and remoterouter. It is typically undesirable for traffic from a distribution router to use a remote routeras a transit path. A typical connection from a distribution router to a remote router wouldhave much less bandwidth than a connection at the network core. Attempting to use aremote router with a limited bandwidth connection as a transit path would generallyproduce excessive congestion to the remote router. The EIGRP Stub Routing feature canprevent this problem by preventing the remote router from advertising core routes back todistribution routers. Routes learned by the remote router from distribution router 1 will notbe advertised to distribution router 2. Since the remote router will not advertise core routesto distribution router 2, the distribution router will not use the remote router as a transit fortraffic destined for the network core.

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a0080087026.html

QUESTION: 3Two Company EIGRP routers are attempting to establish themselves as neighbors. WhichEIGRP multicast packet type is responsible for neighbor discovery?

A. UpdateB. Query

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C. AcknowledgmentD. ReplyE. HelloF. None of the other alternatives apply

Answer: E

Explanation:Remember that simple distance vector routers do not establish any relationship with theirneighbors. RIP andIGRP routers merely broadcast or multicast updates on configuredinterfaces. In contrast, EIGRP routers actively establish relationships with their neighbors,much the same way that OSPF routers do.EIGRP routers establish adjacencies withneighbor routers by using small hello packets. Hellos are sent bydefault every fiveseconds. An EIGRP router assumes that as long as it is receiving hello packets fromknownneighbors, those neighbors (and their routes) remain viable. By formingadjacencies, EIGRP routers do thefollowing: Dynamically learn of new routes that jointheir network Identify routers that become either unreachable or inoperable Rediscoverrouters that had previously been unreachable

QUESTION: 4Company has chosen to use EIGRP for their network routing protocol. Which threestatements are true regarding EIGRP? (Select three)

A. By default, EIGRP uses the Dijkstra algorithm to determine the best path to adestination network based on bandwidth and delay.B. To speed convergence, EIGRP attempts to maintain a successor and feasible successorpath for each destination.C. EIGRP uses hellos to establish neighbor relationships.D. By default, EIGRP performs auto-summarization across classful network boundaries.E. EIGRP uses an area hierarchy to increase network scalability.

Answer: B, C, D

Explanation:The default behavior of EIGRP routers is to automatically summarize routes at thenetwork boundary.EIGRP routers maintain information regarding the successors and thefeasible successors to each network destination. This information is useful in theconvergence time whenever any of the links fail.EIGRP neighbors periodically use hellosto establish the relationship. Should any of the neighbors fail,triggered updates are sent toupdate the network regarding the topology change.

Incorrect Answer:

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A: The Dijkstra algorithm is used by link state routing protocols. EIGRP is considered tobe a hybrid routingprotocol.E: EIGRP networks are inherently flat, as each router is perceived as a peer to every otherEIGRP router. IS-ISand OSPF utilize hierarchical network topologies.

QUESTION: 5You need to configure EIGRP on all routers within the Company network. Which twostatements are Characteristics of the routing protocol EIGRP ? (Select two)

A. Updates are sent as broadcast.B. Updates are sent as multicast.C. LSAs are sent to adjacent neighbors.D. Metric values are represented in a 32-bit format for granularity.

Answer: B, D

Explanation:EIGRP routers establish adjacencies with neighbor routers by using small hello packets.These packets are sent to the multicast IP address of 224.0.0.10. Hellos are sent by defaultevery five seconds. An EIGRP router assumes that as long as it is receiving hello packetsfrom known neighbors, those neighbors (and their routes) remain viable. By formingadjacencies, EIGRP routers do the following:

• Dynamically learn of new routes that join their network

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• Identify routers that become either unreachable or inoperable• Rediscover routers that had previously been unreachable

QUESTION: 6You have been tasked with setting up summarization in the Company EIGRP network.Which two statements are true about EIGRP manual summarization? (Select two)

A. Manual summarization is configured on a per interface basis.B. When manual summarization is configured, auto-summarization is automaticallydisabled by default.C. The summary address is assigned an administrative distance of 10 by default.D. Manual summaries can be configured with the classful mask only.E. The summary address is entered into the routing table and is shown to be sourced fromthe Null0 interface.

Answer: A, E

Explanation:EIGRP automatically summarizes routes at the classful boundary, the boundary where thenetwork address endsas defined by class-based addressing. In most cases, autosummarization is a good thing, keeping the routing tables as compact as possible In thepresence of discontinuous sub networks, automatic summarization must be disabled forrouting to work properly. To turn off auto- summarization, use the followingcommand:Router(config-router)#no auto-summaryEIGRP also enables manualconfiguration of a prefix to use as a summary address. Manual summary routesareconfigured on a per-interface basis. The interface that will propagate the route summarymust first be selectedand then defined with the ip summary-address eigrp command, whichhas the following syntax:Router(config-if)#ip summary-address eigrp autonomous-system-number ipaddress maskadministrative-distanceD 2.1.0.0/16 is a summary, 00:00:22,Null0Notice that the summary route is sourced from Null0, and not an actual interface.

QUESTION: 7Router Company14 is configured as an EIGRP stub router. What are three key conceptsthat apply when configuring the EIGRP stub routing feature in a hub and spoke network?(Select three)

A. Stub routers are not queried for routes.B. A hub router prevents routes from being advertised to the remote router.C. A stub router should have only EIGRP hub routers as neighbors.D. EIGRP stub routing should be used on hub routers only.E. Spoke routers connected to hub routers answer the route queries for the stub router.F. Only remote routers are configured as stubs.

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Answer: A, C, F

Explanation:The Enhanced Interior Gateway Routing Protocol (EIGRP) Stub Routing feature improvesnetwork stability,reduces resource utilization, and simplifies stub router configuration.Stubrouting is commonly used in a hub and spoke network topology. In a hub and spokenetwork, one or moreend (stub) networks are connected to a remote router (the spoke) thatis connected to one or more distributionrouters (the hub). The remote router is adjacentonly to one or more distribution routers. The only route for IPtraffic to follow into theremote router is through a distribution router. This type of configuration is commonlyusedin WAN topologies where the distribution router is directly connected to a WAN. Thedistribution routercan be connected to many more remote routers. Often, the distributionrouter will be connected to 100 or moreremote routers. In a hub and spoke topology, theremote router must forward all nonlocal traffic to a distributionrouter, so it becomesunnecessary for the remote router to hold a complete routing table. Generally,thedistribution router need not send anything more than a default route to the remoterouter.When using the EIGRP Stub Routing feature, you need to configure the distributionand remote routers to useEIGRP, and to configure only the remote router as a stub. Onlyspecified routes are propagated from the remote(stub) router. The router responds toqueries for summaries, connected routes, redistributed static routes,external routes, andinternal routes with the message "inaccessible." A router that is configured as a stubwillsend a special peer information packet to all neighboring routers to reportitsstatusasastub router.

Reference:http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s15/eigrpstb.htm

QUESTION: 8You want to reduce the amount of EIGRP traffic across low speed links in the Companynetwork. Which is the most effective technique to contain EIGRP queries?

A. Using a hierarchical addressing schemeB. Configuring route filtersC. Establishing separate autonomous systemsD. Route summarizationE. None of the other alternatives apply

Answer: D

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Explanation:EIGRP automatically summarizes routes at the classful boundary, the boundary where thenetwork address endsas defined by class-based addressing. In most cases, autosummarization is a good thing, keeping the routingtables as compact as possibleIn thepresence of discontiguous subnetworks, automatic summarization must be disabled forrouting to workproperly. To turn off auto-summarization, use the followingcommand:Router(config-router)#no auto-summaryEIGRP also enables manualconfiguration of a prefix to use as a summary address. Manual summary routesareconfigured on a per-interface basis. The interface that will propagate the route summarymust first be selectedand then defined with the ip summary-address eigrp command, whichhas the following syntax:Router(config-if)#ip summary-address eigrp autonomous-system-number ipaddress maskadministrative-distance

QUESTION: 9Routers Company1 and Company2 have formed an EIGRP neighbor relationship. In orderfor two routers to become EIGRP neighbors, which two values must match? (Select two)

A. K valuesB. DelayC. Autonomous systemD. Hello timeE. Hold timeF. Bandwidth

Answer: A, C

Explanation:Despite being compatible with IGRP, EIGRP uses a different metric calculation and hop-count limitation.EIGRP scales the IGRP metric by a factor of 256. That is because EIGRPuses a metric that is 32-bits long, andIGRP uses a 24-bit metric. By multiplying ordividing by 256, EIGRP can easily exchange information withIGRP.EIGRP also imposes amaximum hop limit of 224, which is slightly less than the 255 limit for IGRP.However,this is more than enough to support most of the largest internetworks. To becomethe neighbor K value shouldbe matched and should belongs to same AS.

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QUESTION: 10Company uses EIGRP as their internal routing protocol. Which three statements are trueabout EIGRP operation? (Select three)

A. The maximum metric for the specific routes is used as the metric for the summaryroute.B. When summarization is configured, the router will also create a route to null 0.C. The summary route remains in the route table, even if there are no more specific routesto the network.D. Automatic summarization across major network boundaries is enabled by default.E. Summarization is configured on a per-interface level.

Answer: B, D, E

Explanation:Using the ip summary-address eigrp summarization command will causes the creation ofan EIGRP summarydefault route to the null 0 interface with an administrative distance of5. Caution should be taken when usingthis as a default route. The low administrativedistance of this default route can cause this route to displacedefault routes learned fromother neighbors from the routing table. If the default route learned from theneighbors isdisplaced by the summary default route, or if the summary route is the only default routepresent,all traffic destined for the default route will not leave the router, instead, this trafficwill be sent to the null 0interface where it is dropped.By default, Cisco routers willautomatically summarize EIGRP routes across major network boundaries. WithEIGRP,

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You can configure a summary aggregate address for a specified interface. If there are anymore specificroutes in the routing table, EIGRP will advertise the summary address out theinterface with a metric equal tothe minimum of all more specific routes.

Incorrect Answer:A: The metric used in a summary route is the best metric from among the summarizedroutes, not themaximum (worst).C: When all of the specific routes used within a summary route are deleted from therouting table, the summaryroute will also be deleted.

QUESTION: 11A link failure in the Company network has caused the EIGRP routers to update theirrouting tables. What action does Company1, an EIGRP router, take when it cannot find afeasible successor for a network?

A. It examines the topology table for a next best path.B. It transitions from passive to active state for that network and queries its neighbors.C. It examines the routing and neighbor tables for the next best path.D. It transitions from active to passive state for that network and queries its neighbors.E. None of the other alternatives apply

Answer: B

Explanation:With EIGRP, A topology table entry for a destination can have one of two states. A routeis considered in thePassive state when a router is not performing a route recomputation.The route is in Active state when a routeris undergoing a route recomputation. If there arealways feasible successors, a route never has to go into Activestate and avoids a routerecomputation.When there are no feasible successors, a route goes into Active state and aroute recomputation occurs. A routerecomputation commences with a router sending aquery packet to all neighbors. Neighboring routers can eitherreply if they have feasiblesuccessors for the destination or optionally return a query indicating that theyareperforming a route recomputation. While in Active state, a router cannot change thenext-hop neighbor it isusing to forward packets. Once all replies are received for a givenquery, the destination can transition toPassive state and a new successor can be selected.

QUESTION: 12EIGRP performs automatic summarization at network boundaries. What administrativedistance is given to these EIGRP summary routes?

A. 1

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B. 90C. 95D. 0E. 5F. 170G. 255H. None of the other alternatives apply

Answer: E

Explanation:EIGRP automatically summarizes routes at the classful boundary, the boundary where thenetwork address endsas defined by class-based addressing. In most cases, autosummarization is a good thing, keeping the routingtables as compact as possibleIn thepresence of discontiguous subnetworks, automatic summarization must be disabled forrouting to workproperly. To turn off auto-summarization, use the followingcommand:Router(config-router)#no auto-summaryDefault Administrative Distance

QUESTION: 13You need to alter the metrics of certain EIGRP routes in the Company network. Whichtwo parameters are used by default to compute the EIGRP metric? (Select two)

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A. MTUB. BandwidthC. DelayD. ReliabilityE. LoadF. Interface up time

Answer: B, C

Explanation:Metrics are the mathematics used to select a route. The higher the metric associated with aroute, the lessdesirable it is. For EIGRP, the Bellman-Ford algorithm uses the followingequation and creates the overall24-bit metric assigned to a route:?? metric = [(K1bandwidth) + [(K2 bandwidth) (256 - load)] + (K3 delay)] [K5 (reliability + K4)]Theelements in this equation are as follows:?? By default, K1 = K3 = 1, K2 = K4 = K5 = 0.Therefore, by default, the metric formulareduces to:metric = (1 bandwidth) + (1delay)metric = bandwidth + delay

QUESTION: 14The Company network is using EIGRP as the network routing protocol. Which of thefollowing statements correctly describe features and characteristics of routing usingEIGRP? (Select three)

A. It sends periodic updates every 60 seconds.B. EIGRP uses DUAL to achieve rapid convergence.C. Adjacencies exist between master routers (MRs) in each domain.D. It uses multicast to discover other EIGRP routers on an internetwork.E. EIGRP provides support for multiple network layer protocols: IPX, AppleTalk, and IP.

Answer: B, D, E

Explanation:B: Enhanced IGRP uses the Diffusing Update based algorithm (DUAL).D: EIGRP use hello multicast packets for neighbor discovery/recovery.E: EIGRP supports IPX, Appletalk, and IP. Separate EIGRP instances can be created foreach routed protocol.

Incorrect Answer:A: EIGRP use triggered updates, not periodic updates.C: Each EIGRP router maintains a neighbor table that lists adjacent routers. However,there is no concept ofmaster router in EIGRP.

Reference:

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"Introduction to Enhanced IGRP (EIGRP)" Cisco website

QUESTION: 15While comparing the tables associated with EIGRP and OSPF, you notice somesimilarities. Which EIGRP table is similar to OSPF’s Link State Adjacency table?

A. Neighbor tableB. Routing tableC. Topology tableD. Successor tableE. None of the other alternatives apply

Answer: A

Explanation:Each EIGRP router maintains a neighbor table that lists adjacent routers. This table iscomparable to theneighbors (adjacency) database used by OSPF .

Incorrect Answer:B: The routing table of EIGRP would compare to the routing table of OSPFC: Both EIGRP and OSPF contain topology tables, which would compare to each other.D: EIGRP does not have a successor table. Successors are maintained in the routing andtopology tables ofEIGRP.

Reference:Building Scalable Cisco Networks (Cisco Press) page 250

QUESTION: 16Which of the following protocols is used in large networks working as service providers?

A. Intermediate System-to-Intermediate System protocol (IS-IS)B. Enhanced Interior Gateway Routing protocol (EIGRP)C. External Border Gateway protocol (eBGP)D. Open Shortest Path First protocol (OSPF)

Answer: A

QUESTION: 17Different types of EIGRP transmissions are sent between neighboring routers. Which threeof the following terms are known as ‘reliable packets’ in EIGRP? (Select three)

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A. HelloB. ACKC. ReplyD. QueryE. Update

Answer: C, D, E

Explanation:Updates are used to convey the reachability of destinations. When a new neighbor isdiscovered, update packetsare sent so the neighbor can build up its topology table. In thiscase, update packets are unicast. In other cases,such as a link cost change, updates aremulticast. Updates are always transmitted reliably.Queries and replies are sent whendestinations go into Active state. Queries are always multicast unless they aresent inresponse to a received query. In this case, it is unicast back to the successor that originatedthe query.Replies are always sent in response to queries to indicate to the originator that itdoes not need to go into Activestate because it has feasible successors. Replies are unicastto the originator of the query. Both queries andreplies are transmitted reliably.EIGRPreliable packets are: Update, Query and Reply.EIGRP unreliable packets are: Hello andAck.

Incorrect Answer:A, B: Hellos are multicast for neighbor discovery/recovery. They do not requireacknowledgment. A hello withno data is also used as an acknowledgment (ack). Acks arealways sent using a unicast address and contain anon-zero acknowledgment number.

Reference:Cisco BSCN version 1.0 study guide, pages 6-18.

QUESTION: 18Which one of the following statements best describes the way EIGRP advertises subnetmask information to its destination networks?

A. EIGRP advertises a prefix length for each destination network.B. EIGRP advertises a fixed length subnet mask for each destination network.C. EIGRP advertises only a classful subnet mask for each destination network.D. EIGRP, like IGRP and RIP, does not advertise a subnet mask for each destinationnetwork.

Answer: A

Explanation:

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EIGRP advertises a prefix length to each destination network. It supports VLSM whichallows subnet masks tobe automatically summarized at the network boundary, and EIGRPcan also be configured to summarize on anybit boundary at any interface.

Incorrect Answer:B: This is incorrect because EIGRP supports Variable Length subnet masks.C: This is incorrect because EIGRP is considered to be a classless protocol, not classful.D: EIGRP is more sophisticated then IGRP and RIP and actually does advertise a subnetmask to eachdestination network.

QUESTION: 19EIGRP was designed specifically not to use excessive bandwidth for routing updates andfunctions across WAN links. If EIGRP is configured on an interface, what is the maximumpercent of its bandwidth EIGRP would use, by default?

A. 10%B. 25%C. 50%D. 75%E. 100%

Answer: C

Explanation:By default, EIGRP will limit itself to using no more than 50% of the available bandwidth.The maximumbandwidth that can be used is a configurable parameter.

Reference:Cisco, Configuration Notes for the Enhanced Implementation ofEIGRP.http://www.cisco.com/warp/public/103/12.html

QUESTION: 20EIGRP supports Variable Length Subnet Masking (VLSM). Which two features of EIGRPare true regarding EIGRP support for VLSM? (Select two)

A. It advertises a routing maskB. It is a classful routing protocolC. It is a classless routing protocolD. It does not advertise a routing mask.

Answer: A, C

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Explanation:EIGRP includes the routing mask when it advertises routes. Subnet mask information mustbe included in allrouting updates for classless protocols. EIGRP is a classless protocol,meaning that is does not solely rely onthe network class in order to find the subnet mask.These two features enable EIGRP to support VLSM.

Incorrect Answer:B: Classful routing protocols do not support VLSM.D: The subnet mask must be included in the route to support VLSM.

QUESTION: 21In an effort to decrease the size of the routing tables in the Company network,summarization is being configured on all routers. Where in an EIGRP network is it mostappropriate to implement route summarization?

A. At area border routersB. At autonomous system boundary routersC. It is done automatically by the DR router in each areaD. Manually at any interface of any EIGRP router within the networkE. In backbone area routers.

Answer: B

Explanation:Enhanced IGRP performs route summarization at classful network boundaries by default.Automatic routesummarization occurs at major network boundaries. ASBRs (autonomoussystem boundary routers) are used atthe major network boundaries.

Incorrect Answer:A, C, E: Area Border Router and DR are used in OSPF, but not in EIGRP. Backbone arearouters are alsoconcepts used in OSPF, but not in EIGRP.D: Manual summarization can be done in any interface at any router within network, butthis is not thepreferred solution. Summarizing manually at each router can result in blackhole routing. However, doneproperly this is an acceptable practice. If the question calls formore than one answer then the best choicewould be B and D.calls for more than oneanswer then the best choice would be B and D.

QUESTION: 22The Company network is using route summarization to decrease the size of the routingtables. In this EIGRP network, which of the following describes the best method forimplementing summarization?

A. At WAN interfaces.

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B. Manually at major network boundaries.C. Dynamically at discontiguous interfaces.D. Dynamically at major network boundaries.E. None of the other alternatives apply

Answer: D

Explanation:EIGRP supports arbitrary route summarization. Route summarization takes placeautomatically at majornetwork boundaries (where network are supernetted).Note: Routesummarization is the consolidation of advertised addresses.

Incorrect Answer:A: Manually configuring summarization at WAN boundaries is not necessarilyrecommended in all situations.If the routers belong to the same major network boundarythen summarization should not be configured.B: Route summarization is automatic in EIGRP, and it is recommended to keep thedefaults.C: Route summarization should only be applied at contiguous interfaces. Choosing thisoption would mostlikely lead to black hole routing, making many networks unreachable.

QUESTION: 23The Company network is running EIGRP on the T1 links within their NBMA frame relaynetwork. By default what would the hold time be for hello packets across these WANlinks?

A. 15 secondsB. 30 secondsC. 90 secondsD. 180 secondsE. 5 Seconds

Answer: D

Explanation:EIGRP sends hello packets every 5 seconds on high bandwidth links and every 60 secondson low bandwidthmultipoint links. The hold time is typically three times the hello interval.In this scenario, on slow NBMAmedia, hold time will be 180 seconds.

Incorrect Answer:A, B, C: Although the hello timers can be manually configured for these values, they arenot the default time.E: This is the default for high bandwidth links, such as Ethernet networks.

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Reference:Enhanced Interior Gateway RoutingProtocolhttp://www.cisco.com/warp/public/103/eigrp1.html

QUESTION: 24EIGRP is being used as the routing protocol within the Company network. Which two ofthe following features allow EIGRP to support classless routing? (Select two)

A. Djikstra’s algorithmB. discontiguous subnetsC. variable length subnet masksD. periodic update announcementsE. unequal path-cost load balancing

Answer: B, C

Explanation:B: Discontiguous subnets are supported by EIGRP. This is a classless routing protocolfeature.C: EIGRP support variable length subnet masks (VLSM). This is a classless routingprotocol feature.

Incorrect Answer:A: EIGRP use the DUAL algorithm, not the Djikstra's algorithm. The Djikstra algorithm isused by distancevector protocols. EIGRP is considered to be a hybrid routing protocol.D: EIGRP use periodic hello messages, not update announcements. EIGRP use updatepackets to conveyreachability of destinations. When a new neighbor is discovered, Updatepackets are sent so the neighborcan build up its. These are not periodic, however.E: IGRP and EIGRP support unequal cost path load balancing, which is known asvariance. However, this isnot a classless feature of EIGRP.Note: Classless routing protocols include the routing mask with the route advertisement.This enablesdiscontiguous subnets and variable length subnet masks.

Reference:Introduction to Enhanced IGRP (EIGRP)http://www.cisco.com/warp/public/103/1.htmlHow Does Unequal Cost Path LoadBalancing (Variance) Work in IGRP and EIGRP?http://www.cisco.com/warp/public/103/19.html

QUESTION: 25The Company network administrator has issued the “EIGRP stub” command on routerCompany8. What is the purpose of the “EIGRP stub” configuration command?

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A. to reduce the convergence time by enabling the EIGRP stub router to propagate theEIGRP queries from the EIGRP hub router.B. to increase scalability by limiting the EIGRP query range.C. to reduce the size of the routing table by blocking the D EX (External EIGRP) routesinto the EIGRP stub router.D. to reduce the convergence time by enabling the EIGRP stub router to also performquery requests to the EIGRP hub router.E. None of the other alternatives apply.

Answer: B

Explanation:The Enhanced Interior Gateway Routing Protocol (EIGRP) Stub Routing feature improvesnetwork stability,reduces resource utilization, and simplifies stub router configuration.Stubrouting is commonly used in a hub and spoke network topology. In a hub and spokenetwork, one or moreend (stub) networks are connected to a remote router (the spoke) thatis connected to one or more distributionrouters (the hub). The remote router is adjacentonly to one or more distribution routers. The only route for IPtraffic to follow into theremote router is through a distribution router. This type of configuration is commonlyusedin WAN topologies where the distribution router is directly connected to a WAN. Thedistribution routercan be connected to many more remote routers. Often, the distributionrouter will be connected to 100 or moreremote routers. In a hub and spoke topology, theremote router must forward all nonlocal traffic to a distributionrouter, so it becomesunnecessary for the remote router to hold a complete routing table. Generally,thedistribution router need not send anything more than a default route to the remoterouter.When using the EIGRP Stub Routing feature, you need to configure the distributionand remote routers to useEIGRP, and to configure only the remote router as a stub. Onlyspecified routes are propagated from the remote(stub) router. The router responds toqueries for summaries, connected routes, redistributed static routes,external routes, andinternal routes with the message "inaccessible." A router that is configured as a stubwillsend a special peer information packet to all neighboring routers to report its status as astub router.Any neighbor that receives a packet informing it of the stub status will notquery the stub router for any routes,and a router that has a stub peer will not query thatpeer. The stub router will depend on the distribution routerto send the proper updates to allpeers.Router(config-router)# eigrp stub [receive-only | connected | static | summary]:Configures a remote router asan EIGRP stub router.

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a0080087026.html

QUESTION: 26Router Company1 is configured as shown below:router eigrp 100

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network 10.0.0.0eigrp stub Based on the information shown above, which two types of routes will beadvertised?(Select two)

A. Receive-onlyB. StubC. StaticD. SummaryE. ConnectedF. Dynamic

Answer: D, E

Explanation:The Enhanced Interior Gateway Routing Protocol (EIGRP) Stub Routing feature improvesnetwork stability,reduces resource utilization, and simplifies stub router configuration.Stubrouting is commonly used in a hub and spoke network topology. In a hub and spokenetwork, one or moreend (stub) networks are connected to a remote router (the spoke) thatis connected to one or more distributionrouters (the hub). The remote router is adjacentonly to one or more distribution routers. The only route for IPtraffic to follow into theremote router is through a distribution router. This type of configuration is commonlyusedin WAN topologies where the distribution router is directly connected to a WAN. Thedistribution routercan be connected to many more remote routers. Often, the distributionrouter will be connected to 100 or moreremote routers. In a hub and spoke topology, theremote router must forward all nonlocal traffic to a distributionrouter, so it becomesunnecessary for the remote router to hold a complete routing table. Generally,thedistribution router need not send anything more than a default route to the remoterouter.When using the EIGRP Stub Routing feature, you need to configure the distributionand remote routers to useEIGRP, and to configure only the remote router as a stub. Onlyspecified routes are propagated from the remote(stub) router. The router responds toqueries for summaries, connected routes, redistributed static routes,external routes, andinternal routes with the message "inaccessible." A router that is configured as a stubwillsend a special peer information packet to all neighboring routers to report its status as astub router.Any neighbor that receives a packet informing it of the stub status will notquery the stub router for any routes,and a router that has a stub peer will not query thatpeer. The stub router will depend on the distribution routerto send the proper updates to allpeers.Router(config-router)# eigrp stub [receive-only | connected | static | summary]:Configures a remote router asan EIGRP stub router.

QUESTION: 27You need to configure EIGRP on a new Company router. Which command should youissue first to configure EIGRP for IP?

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A. router eigrp autonomous-system-numberB. ip eigrp autonomous-system-numberC. ip eigrp routingD. router eigrp process-idE. None of the other alternatives apply

Answer: A

Explanation:Perform the following steps to configure EIGRP for IP:1. Use the following to enableEIGRP and define the autonomous system.Router(config)#router eigrp autonomous-system- numberThe autonomous-system-number is the number that identifies theautonomous system. It is used to indicate allrouters that belong within the internetwork.This value must match all routers within the internetwork.2. Indicate which networksbelong to the EIGRP autonomous system on the local router.Router(config-router)#network network-numberThe network-number determines which interfaces of therouter are participating in EIGRP and which networksare advertised by the router.

QUESTION: 28You need to configure route summarization on a Company EIGRP router. Which is thecorrect command format to configure EIGRP summary route?

A. ip summary-route eigrp as-number address maskB. ip summary-address as-number address maskC. ip auto-summary as-number address maskD. ip auto-summary eigrp as-number address maskE. ip summary-address eigrp as-number address maskF. None of the other alternatives apply

Answer: E

Explanation:EIGRP automatically summarizes routes at the classful boundary, the boundary where thenetwork address endsas defined by class-based addressing. In most cases, autosummarization is a good thing, keeping the routingtables as compact as possibleIn thepresence of discontiguous subnetworks, automatic summarization must be disabled forrouting to workproperly. To turn off auto-summarization, use the followingcommand:Router(config-router)#no auto-summaryEIGRP also enables manualconfiguration of a prefix to use as a summary address. Manual summary routesareconfigured on a per-interface basis. The interface that will propagate the route summarymust first be selectedand then defined with the ip summary-address eigrp command, which

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has the following syntax:Router(config-if)#ip summary-address eigrp autonomous-system-number ipaddress maskadministrative-distance

QUESTION: 29The Company EIGRP network is displayed below: Based on the network shown above,what optional EIGRP configuration statements will be required to achieve full connectivitywithin AS 100?

A. Use the EIGRP “no auto-summary” command on Company1 and Company2.B. Use the “passive interface” on the Company1 and Company2 interface that connects tothe10.1.1.0/24 and 10.1.2.0/24 subnet respectively.C. Use the EIGRP “no auto-summary” command on Company3 and Company4.D. Use the “passive interface” command between the Company3 and Company1connection and between the Company3 and Company2 connection.E. Use the “variance” command on Company3.F. None of the other alternatives apply.

Answer: A

Explanation:EIGRP automatically summarizes routes at the classful boundary, the boundary where thenetwork address endsas defined by class-based addressing. In most cases, autosummarization is a good thing, keeping the routingtables as compact as possibleIn thepresence of discontiguous subnetworks, automatic summarization must be disabled forrouting to workproperly. To turn off auto-summarization, use the followingcommand:Router(config-router)#no auto-summary

QUESTION: 30

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You want to enable load sharing across the Company WAN using EIGRP. Whichconfiguration command is used to enable EIGRP unequal-cost path load balancing?

A. VarianceB. DistanceC. Maximum-pathsD. Default-metricE. MetricF. None of the other alternatives apply

Answer: A

Explanation:Every routing protocol supports equal cost path load balancing. In addition, InteriorGateway Routing Protocol(IGRP) and EIGRP also support unequal cost path loadbalancing. Use the variance n command in order to instruct the router to include routeswith a metric of less than n times the minimum metric route for that destination. Thevariable n can take a value between 1 and 128. The default is 1, which means equal costload balancing. Traffic is also distributed among the links with unequal costs,proportionately, with respect to the metric.

QUESTION: 31You are a network administrator on a Cisco router that’s running EIGRP. You want toaggregate some of the routes. Which of the following commands below would you enter toconfigure the summary route you need?

A. ip auto-summary as-number address maskB. ip summary-address as-number address maskC. ip auto-summary eigrp as-number address maskD. ip summary-route eigrp as-number address maskE. ip summary-address eigrp as-number address mask

Answer: E

Explanation:The ip summary-address eigrp command is used to configure a summary aggregateaddress for a specifiedinterface.Syntax:ip summary-address eigrp autonomous-system-number address mask

Incorrect Answer:A, C, D: No such command exists using this syntax.

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B: We must specify the appropriate protocol with the eigrp keyword.

QUESTION: 32Router Company1 has a 256kbps serial interface link to another Company location. Theconfiguration file of this interface is shown below: interface serial 0/0 bandwidth 56 ipbandwidth- percent eigrp 1 200 From the command output above, how many kbps ofbandwidth is allocated for EIGRP traffic?

A. 56 kbpsB. 112 kbpsC. 128 kbpsD. 256 kbpsE. None of the other alternatives apply

Answer: B

Explanation:The bandwidth-percent command tells EIGRP what percentage of the configuredbandwidth it may use. The default is 50 percent. Since the bandwidth command is alsoused to set the routing protocol metric, it may beset to a particular value for policy reasons.In this case, it is set to 56 kbps even though the actual link is 256kbps. The bandwidth-percent command can have values greater than 100 if the bandwidth is configuredartificially low due to such policy reasons. In this specific case, the bandwidth configuredon the interface is56kbps, so 200 percent of this value is 112 kbps.

Reference:http://www.cisco.com/en/US/tech/tk365/tk207/technologies_tech_note09186a0080094063.shtml

QUESTION: 33EIGRP is being used as the routing protocol on the Company network. Whiletroubleshooting some network connectivity issues, you notice a large number of EIGRPSIA (Stuck in Active) messages. What causes these SIA routes? (Select two)

A. The neighboring router stops receiving ACK packets from this router.B. The neighboring router starts receiving route updates from this router.C. The neighboring router is too busy to answer the query (generally caused by high CPUutilization).D. The neighboring router is having memory problems and cannot allocate the memory toprocess the query or build the reply packet.

Answer: C, D

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Explanation:SIA routes are due to the fact that reply packets are not received. This could be caused bya router which isunable to send reply packets. The router could have reached the limit ofits capacity, or it could bemalfunctioning.

Incorrect Answer:A: Missing replies, not missing ACKs, cause SIA.B: Routes updates do not cause SIA.Notes: If a router does not receive a reply to alloutstanding queries within 3 minutes, the route goes to the stuckin active (SIA) state. Therouter then resets the neighbors that fail to reply by going active on all routesknownthrough that neighbor, and it re- advertises all routes to that neighbor.

Reference:Enhanced Interior Gateway RoutingProtocolhttp://www.cisco.com/warp/public/103/eigrp3.html

QUESTION: 34Part of the routing table of router Company1 is displayed below:

From analyzing the above command output, what is the administrative distance of theexternal EIGRP routes?

A. 24B. 32C. 90D. 170E. 27316F. None of the other alternatives apply

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Answer: D

Explanation:By default an external EIGRP route has a value of 170. By examining the exhibit we seethat this default valueof the external EIGRP routes (see D-EX in exhibit) indeed is set to170. The first value within the bracketsdisplay the AD, so with a value of [170/27316] theAD is 170 and the metric of the route is 27316.

Incorrect Answer:A, B: This is the subnet mask used for some of the routes in the table.C: This is the AD of the internal EIGRP routes, which is the defaultE: This is the EIGRP metric of the external EIGRP routes.

Reference:What Is Administrative Distance?http://www.cisco.com/warp/public/105/admin_distance.html

QUESTION: 35The following command was issued on router Company2:

Given the above output shown above, which statement is true?

A. 192.168.1.0 is a redistributed route into EIGRP.B. 192.168.1.0 is a summarized route.C. 192.168.1.0 is a static route.D. 192.168.1.0 is equal path load balancing with 172.16.1.0.E. None of the other alternatives apply

Answer: A

Explanation:When EIGRP learns the routing information from the different routing protocol it uses DEX symbol to indicate that this routing information has learned from other routingprotocol.

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QUESTION: 36A network administrator is troubleshooting an EIGRP connection between routerCompany1 with IP address 10.1.2.1 and Company2 with IP address 10.1.2.2. Given thedebug output on Company1 shown below, which two statements are true? (Select 2)

A. Company1 received a hello packet with mismatched hello timers.B. Company1 will form an adjacency with Company2.C. Company1 received a hello packet with mismatched metric-calculation mechanisms.D. Company1 received a hello packet with mismatched autonomous system numbers.E. Company1 received a hello packet with mismatched authentication parameters.F. Company1 will not form an adjacency with Company2.

Answer: C, F

Explanation:Metrics are the mathematics used to select a route. The higher the metric associated with aroute, the lessdesirable it is. For EIGRP, the Bellman-Ford algorithm uses the followingequation and creates the overall24-bit metric assigned to a route:?? metric = [(K1bandwidth) + [(K2 bandwidth) (256 - load)] + (K3 delay)] [K5 (reliability + K4)]Theelements in this equation are as follows:?? By default, K1 = K3 = 1, K2 = K4 = K5 = 0.Therefore, by default, the metric formulareduces to:metric = (1 bandwidth) + (1delay)metric = bandwidth + delayK Values should be same to become the EIGRPneighbors.

QUESTION: 37Study the exhibit below carefully:

If the configuration shown below is added to Company1, which three route entries willEIGRP advertise to neighboring routers? (Select three) router eigrp 10 network 10.0.0.0eigrp stub

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A. 192.168.20.0/24B. 10.1.2.0/24C. 10.1.1.0/24D. 10.1.3.0/24E. 10.0.0.0/8

Answer: C, D, E

Explanation:The Enhanced Interior Gateway Routing Protocol (EIGRP) Stub Routing feature improvesnetwork stability,reduces resource utilization, and simplifies stub router configuration.Stubrouting is commonly used in a hub and spoke network topology. In a hub and spokenetwork, one or moreend (stub) networks are connected to a remote router (the spoke) thatis connected to one or more distributionrouters (the hub). The remote router is adjacentonly to one or more distribution routers. The only route for IPtraffic to follow into theremote router is through a distribution router. This type of configuration is commonlyusedin WAN topologies where the distribution router is directly connected to a WAN. Thedistribution routercan be connected to many more remote routers. Often, the distributionrouter will be connected to 100 or moreremote routers. In a hub and spoke topology, theremote router must forward all nonlocal traffic to a distributionrouter, so it becomesunnecessary for the remote router to hold a complete routing table. Generally,thedistribution router need not send anything more than a default route to the remoterouter.When using the EIGRP Stub Routing feature, you need to configure the distributionand remote routers to useEIGRP, and to configure only the remote router as a stub. Onlyspecified routes are propagated from the remote(stub) router. The router responds toqueries for summaries, connected routes, redistributed static routes,external routes, andinternal routes with the message "inaccessible." A router that is configured as a stubwillsend a special peer information packet to all neighboring routers to report its status as astub router.Any neighbor that receives a packet informing it of the stub status will notquery the stub router for any routes,and a router that has a stub peer will not query thatpeer. The stub router will depend on the distribution routerto send the proper updates to allpeers.

QUESTION: 38Two Company routers are connected together as shown below:

Company1 configuration exhibit:

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Study the exhibits carefully. EIGRP has been configured on routers Company1 andCompany2. However, Company1 does not show Company2 as a neighbor and does notaccept routing updates from Company2. What could be the cause of the problem?

A. The “no auto-summary command” has not been issued under the EIGRP process onboth routers.B. EIGRP cannot form neighbor relationship and exchange routing updates with asecondary address.C. EIGRP cannot exchange routing updates with a neighbor's router interface that isconfigured with two IP addresses.

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D. Interface E0 on router Company1 has not been configured with a secondary IP addressof 10.1.2.1/24.E. None of the other alternatives apply

Answer: B

Explanation:Remember that simple distance vector routers do not establish any relationship with theirneighbors. RIP and IGRP routers merely broadcast or multicast updates on configuredinterfaces. In contrast, EIGRP routers actively establish relationships with their neighbors,much the same way that OSPF routers do.EIGRP routers establish adjacencies withneighbor routers by using small hello packets. Hellos are sent bydefault every fiveseconds. An EIGRP router assumes that as long as it is receiving hello packets fromknown neighbors, those neighbors (and their routes) remain viable. By formingadjacencies, EIGRP routers do the following: Dynamically learn of new routes that jointheir network Identify routers that become either unreachable or inoperable Rediscoverrouters that had previously been unreachable

QUESTION: 39While troubleshooting an EIGRP routing problem you notice that one of the Companyrouters have generated a large number of SIA messages. What are two possible causes forEIGRP Stuck-In-Active routes? (Select two)

A. Some query or reply packets are lost between the routers.B. The neighboring router starts receiving route updates from this router.C. A failure causes traffic on a link between two neighboring routers to flow in only onedirection (unidirectional link).D. The neighboring router stops receiving ACK packets from this router.

Answer: A, C

Explanation:The acknowledgement does not reach the destination or they are too delayed. This isnormally due to too many routing topology changes, or a router with insufficient memory.Note: In some circumstances, it takes a very long time for a query to be answered. So long,in fact, that the router that issued the query gives up and clears its connection to the routerthat isn't answering, effectively restarting the neighbor session. This is known as a stuck inactive (SIA) route. The most basic SIA routes occur when it simply takes too long for aquery to reach the other end of the network and for a reply to travel back.

Incorrect Answer:B: Does not apply to SIA. This is the normal operation of EIGRP.D: Ack packets don't reply to Queries, only Reply do.

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Reference:http://www.cisco.com/warp/public/103/eigrp3.html

QUESTION: 40EIGRP uses five generic packet types (hello, updates, queries, replies,acknowledgements). If you wished to view the statistics for these packets, which IOScommand should you use?

A. debug eigrp packetsB. show ip eigrp trafficC. show ip eigrp topologyD. show ip eigrp neighbors

Answer: B

Explanation:The show ip eigrp traffic command displays the number of Enhanced IGRP (EIGRP)packets sent andreceived. Example:The following is sample output from the show ip eigrptraffic command:Router# show ip eigrp trafficIP-EIGRP Traffic Statistics for process77Hellos sent/received: 218/205Updates sent/received: 7/23Queries sent/received:2/0Replies sent/received: 0/2Acks sent/received:21/14

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_command_reference_chapter09186a00800ca5a9.html#wp1018815 Questions)

QUESTION: 41The Company network is shown below, along with the relevant router configurations:

Company1# show run interface Loopback0ip address 10.10.10.1 255.255.255.0!interface Ethernet0ip address 172.29.1.1 255.255.255.0media-type 10BaseT!!

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router eigrp 999 redistribute connected network 172.29.0.0 auto-summaryno eigrp log-neighbor-changes!ip classlessno ip http server Company2# show run interface Ethernet0ip address 172.29.1.2 255.255.255.0media-type 10BaseT!interface Ethernet1ip address 172.19.2.2 255.255.255.0media-type 10BaseT!router eigrp 999 network 172.19.0.0 network 172.29.0.0!ip classlessno ip http server Company3# show run interface Ethernet1/0ip address 172.19.2.3 255.255.255.0!router eigrp 999network 172.19.0.0auto-summaryno eigrp log-neighbor-changes!ip classlessip http serverWith the topology found in the graphic, what will the Company1 loopback 0 be in theCompany3 routing table?

A. It will show up in the routing table as D 10.0.0/8.B. It will show up in the routing table as D EX 10.0.0.0/8.C. It will show up in the routing table as D 10.0.0./24.D. It will not show up in Company3 routing table because there is no network commandon Company1.

Answer: B

Explanation:Because router Company1 is configured with route redistribution, it will redistribute theconnected loopback networkinto EIGRP. Because redistributed routes will show up asexternal EIGRP routes in the routing table, choice Bis correct. Although the loopbackinterface is using a /24 subnet mask, EIGRP summarizes at networkboundaries by defaultso the network will appear as the class A network of 10.0.0.0/8 in the routing table oftheother routers.

Incorrect Answer:A: The route will be external, since it was redistributed into EIGRP.

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C: It will be external because of redistribution, and it will also be summarized since that isthe default behaviorof EIGRP.D: Although it was not configured under the EIGRPnetwork command, it would be redistributed because it is a connected route.

QUESTION: 42The Company EIGRP network is displayed in the following topology diagram:

You work as a network technician at Company.com. Study the exhibits carefully. If thecommand “variance 3” was added to the EIGRP configuration of Company5, which pathor paths would be chosen to route traffic from Company5 to network X?

A. Company5-Company2-Company1B. Company5-Company2-Company1 and Company5-Company3-Company1.C. Company5-Company3-Company1 and Company5-Company4-Company1.D. Company5-Company2-Company1,Company5-Company3-Company1, and Company5-Company4- Company1.

Answer: B

Explanation:Every routing protocol supports equal cost path load balancing. In addition, InteriorGateway Routing Protocol(IGRP) and EIGRP also support unequal cost path loadbalancing. Use the variance n command in order toinstruct the router to include routes witha metric of less than n times the minimum metric route for thatdestination. The variable ncan take a value between 1 and 128. The default is 1, which means equal costloadbalancing. Traffic is also distributed among the links with unequal costs,proportionately, with respect to themetric.In this question the variance 3 command is used.

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In this instance, Company5 can get to Net X using the pathtk5-tk3 = metric of 10, and tk3-tk1 = 10 as well with the FD between tk5 - tk1 being 10 + 10 = 20. Therefore,we can loadbalance on any route that had an FD of 3x the successor, or 3x20, which is 60ImportantNote: If a path does not meet the feasibility condition, the path is not used in loadbalancing. This iswhy chose D is wrong as this path has an Advertised Distance of 25which is greater than the successors FD.The link below refers to an example that is nearlyidentical to the example in this question, except theirs used avariance of 2 and thisquestion used a variance of 3.

Reference:http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009437d.shtml

QUESTION: 43A Company network administrator is troubleshooting an EIGRP configuration across adiscontiguous network. What must the administrator do to ensure all of the Companyrouters have the correct routing information?

A. The administrator must enable classless routing with the command “ip classless”B. The administrator must disable automatic summarization with the command “no auto-summary”C. The administrator must specify a default network with the command “ip default-network”D. Nothing, EIGRP supports discontiguous networks by default.E. The administrator must enable manual summarization with the command “ip summary-address”F. None of the other alternatives apply

Answer: B

Explanation:EIGRP automatically summarizes routes at the classful boundary, the boundary where thenetwork address endsas defined by class-based addressing. In most cases, autosummarization is a good thing, keeping the routingtables as compact as possibleIn thepresence of discontiguous subnetworks, automatic summarization must be disabled forrouting to workproperly. To turn off auto-summarization, use the followingcommand:Company1(config-router)#no auto-summary

QUESTION: 44The Company EIGRP network is shown below:

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In this network, router Company5 is configured with the EIGRP “variance 2” command.What path will Router Company5 take to reach Router Company1?

A. Both Company5-Company2-Company1 and Company5-Company4-Company1B. Only Company5-Company2-Company1C. Only Company5-Company3-Company1D. All available paths.E. Only Company5-Company4-Company1F. Both Company5-Company2-Company1 and Company5-Company3-Company1G. None of the other alternatives apply

Answer: F

Explanation:Use the variance n command in order to instruct the router to include routes with a metricof less than n timesthe minimum metric route for that destination. The variable n can takea value between 1 and 128. The defaultis 1, which means equal cost load balancing.Traffic is also distributed among the links with unequal costs,proportionately, with respectto the metric. In this case, the best path has a total metric of 20, so using avariance of 2will allow for paths up to a metric of 40 to be used.

QUESTION: 45The Company OSPF network has been segmented into numerous different areas. Whichthree choices below are advantages to creating multiple areas in OSPF? (Select three)

A. Fewer hello packetsB. Fewer adjacencies needed

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C. Less frequent SPF calculationsD. Smaller routing tablesE. Reduced Link State Update (LSU) overhead

Answer: C, D, E

Explanation:Three issues can overwhelm an OSPF router in a heavily populated OSPF network: highdemand for router processing and memory resources large routing tables large topologytablesIn a very large internetwork, changes are inevitable. OSPF routers are likely to runSPF calculations frequently,which deprive the router of precious CPU cycles and memoryresources.Not only is the routing table frequently recalculated in a large OSPF network,but it also risks being overstuffedwith multiple paths and hundreds of routes. Full routingtables make routers less efficient. Finally, the link-statedatabase, which must contain acomplete topology of the network, will also threaten to consume resources andslow downthe router. Reduced frequency of SPF calculations - Because detailed route information iskept within each area,it is not necessary to flood all link-state changes to all other areas.Therefore, only those routers affectedby a change need to run the SPF calculation. Smallerrouting tables - When using multiple areas, detailed route entries for specific networkswithinan area are kept inside the area. Rather than advertise these explicit routes outsidethe area, the routescan be summarized into one or more summary routes. Advertising thesesummaries reduces the amountof LSAs propagated between areas but allows all networksto remain reachable. Reduced link-state update (LSU) overhead - LSUs can contain avariety of LSA types, includinglink- state information and summary information. Ratherthan send an LSU about each network to everyarea, advertise a single route or a fewsummarized routes between areas to reduce the overheadassociated with LSUs that crossmultiple areas.

QUESTION: 46Which of the three areas below are valid OSPF area types? (Select three)

A. StubB. ActiveC. RemoteD. BackboneE. Ordinary or standard

Answer: A, D, E

Explanation:OSPF Area Types:The characteristics that are assigned to an area control the type of routeinformation that it can receive. Forexample, the size of routing tables may need to beminimized in an OSPF area. In this case configure the routersto operate in an area thatdoes not accept external routing information, Type 5 LSAs.The following are several area

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types that are possible: Standard area - A standard area can accept link updates and routesummaries. Backbone area (transit area) - When interconnecting multiple areas, thebackbone area is the centralentity to which all other areas connect. The backbone area isalways Area 0. All other areas mustconnect to this area to exchange route information. TheOSPF backbone has all the properties of astandard OSPF area. Stub area - A stub area is anarea that does not accept information about routes external to theautonomous system, theOSPF internetwork, such as routes from non-OSPF sources. If routers need toreachnetworks outside the autonomous system, they use a default route. A default route is notedas0.0.0.0/0. Totally stubby area - A totally stubby area is an area that does not acceptexternal autonomous system(AS) routes and summary routes from other areas internal tothe autonomous system. Instead, if therouter needs to send a packet to a network externalto the area, it sends it using a 0.0.0.0/0 default route.Totally stubby areas are a Ciscoproprietary feature. Not-so-stubby area (NSSA) - An NSSA is an area that is similar to astub area but allows for importingexternal routes as Type 7 LSAs and translation ofspecific Type 7 LSA routes into Type 5 LSAs.

QUESTION: 47Router Company1 has an interface in one OSPF area and another interface in a differentOSPF are a. What kind of router is Company1?

A. ABRB. ASBRC. Internal routerD. Backbone routerE. None of the other alternatives apply

Answer: A

Explanation:An ABR (Area Border Router) shares an interface with at least one other OSPF area.

Incorrect Answer:B: An ASBR (Autonomous System Border Router) have at least one interface in a non-OSPF network.C: An internal router is only connected to routers in the internal area.D: A backbone router has at least one interface in the backbone, also known as Area 0.

QUESTION: 48What kind of information can you find in a type 3 OSPF network summary link LSA?

A. Summary of routes in the AS.B. Summary of link states in an OSPF area.C. Summary of IP subnets in an OSPF area.D. Summary of metric coast from ABR to ASBR.

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E. None of the other alternatives apply.

Answer: C

Explanation:A type 3 area LSA is Inter-area prefix LSA for an ABR. It advertises internal networks torouters in other areas(interarea routes). Type 3 LSAs may represent a single network or aset of networks summarized into oneadvertisement. Only ABRs generate summary LSAs.In OSPF for IPv6, addresses for these LSAs are expressedas prefix, prefix length insteadof address, mask. The default route is expressed as a prefix with length0.

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide_chapter09186a0080145c56.html

QUESTION: 49What does Cisco recommend for those who set up networks with multiple OSPF areas?(Select two)

A. There should not be more than three areas per router.B. Area 0 must be larger than any subsequent OSPF area.C. A router can be a DR or BDR for more than one LAN.D. You should not run more than one instance of the OSPF process on an ABR.

Answer: C, D

Explanation:C: A router can be a DR or BDR for more than one LAN. Since the loopback address isnormally used as therouter ID, this ID is used for all LAN segments.D: Running multiple OSPF processes on the same router is not recommended because itcreates multipledatabase instances that add extra overhead.

Incorrect Answer:A: There is no such limit. The hierarchical structure could be larger.B: There is no requirement that Area 0 must be the largest OSPF area.

QUESTION: 50When designing and implementing OSPF in multiple areas; what should be taken inconsideration? (Select two)

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A. Each area must connect to area 0.B. Each area must have a unique AS number.C. Remote areas must be configured as stub or NSSA areas.D. Traffic between two areas must travel across the backbone area.

Answer: A, D

Explanation:In OSPF, all areas must be connected to a backbone area, which is area 0. It is alsorequired that traffic fromone area to another non-backbone area must traverse area 0, sinceall areas must connect to area 0.

Incorrect Answer:B: OSPF routers within the same Autonomous System should be configured with the sameAS number. TheAS number is also called the OSPF process ID .C: Remote areas are not required to be either stub or not so stubby areas.

QUESTION: 51You are the administrator of the large Company OSPF and are considering dividing it tomultiple areas. What are two advantages of configuring multiple OSPF areas? (Select two)

A. It eliminates the need for a DR or BDR in the OSPF network.B. It eliminates security concerns by segregating portions of the network.C. Type 1 and 2 LSAs are confined to a single area, reducing routing overhead.D. Area members have smaller topological databases than if the network was one largearea, requiring less CPU to derive routes.

Answer: C, D

Explanation:C: Link State update (LSU) traffic is reduced. Rather than send an LSU about eachnetwork within an area, you can advertise a single or fewer summarized routes betweenareas to reduce the overhead associated with linkstate updates when they are crossingareas. Note: All LSA types, except the AS-external-LSAs (LS type = 5), are floodedthroughout a single area only.D: Topological database size would decrease and fewer CPU cycles would be required tocalculate routes.

Incorrect Answer:A: A DR and BDR for each area would still be required.B: Security concerns would not be eliminated. There are no security advantages in usingmore than one area inan OSPF network.

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QUESTION: 52OSPF has been configured on router Company1, which lies on a multi point network. Onthis multiaccess network, what type of router floods type 2 Link State Advertisements(LSAs) into an OSPF area?

A. DRB. ABRC. BDRD. ASBRE. None of the other alternatives apply

Answer: A

Explanation:Type 2 LSAs are generated by Designated Routers (DRs) in multi-access networks. Theydescribe the set of routers attached to a particular network and are flooded within the areathat contains the network only. Note: Instead of routers exchanging link-state informationwith every other router on the segment, each router sends the link-state information to theDR and Backup Designated Router (BDR). The DR sends each router's link-stateinformation to all other routers in the network. This flooding process significantly reducesthe router related traffic on a segment.

Incorrect Answer:B: Area Border Routers generate Type 3 and Type 4 LSAs.C: BDRs are just used for backup, should the DR fail.D: Autonomous System Boundary Routers (ASBRs) generate Type 5 LSAs.

QUESTION: 53You want router one of the OSPF areas on your network to be able to accept type 7external routers, but not type 5 external routes. What kind of area should be configured toaccomplish this?

A. A not-so stubby areaB. A stubby areaC. A totally stubby areaD. A backbone areaE. An on-demand area

Answer: A

Explanation:

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The NSSA external LSA -Identified as Type 7, these LSAs are created by the ASBRresiding in a not so stubby area (NSSA). This LSA is similar to an autonomous systemexternal LSA, except that this LSA is contained within the NSSA area and is notpropagated into other areas, but it is converted into a Type 5 LSA bythe ABR. An NSSA isan area that is seen as a stub area but can receive external routes, which it will notpropagate into the backbone area and thus the rest of the OSPF domain. Another LSA,Type 7, is created specifically for the NSSA. This LSA can be originated andcommunicated throughout the area, but it will not be propagated in to other areas,including Area 0. If the information is to be propagated throughout the AS, it is translatedinto an LSA Type 5 at the NSSA ABR.

QUESTION: 54Router Company1 is an OSPF router connected to area 1. To create an NSSA totallystubby area in Area 1, what commands should be configured on the NSSA ABR?

A. router ospf 1area 1 nssaB. router ospf 1area 1 nssa no-summaryC. router ospf 1area 1 nssa no-redistributionD. router ospf 1area 1 nssa default-information originate metric-type 2E. router ospf 1area 1 nssa default-information originateF. None of the other alternatives apply

Answer: B

Explanation:Not-so-stubby area (NSSA) - An NSSA is an area that is similar to a stub area but allowsfor importing external routes as Type 7 LSAs and translation of specific Type 7 LSAroutes into Type 5 LSAsTo configure an OSPF area as a NSSA, configure all OSPF routerinterfaces that belong to the area using the following command syntax: Router(config-router)#area area-id nssa [no- summary]Typically, use the optional keyword no-summarywhen configuring NSSA on an ABR. This prevents Type 3and Type 4 summary routesfrom flooding the NSSA area and minimizes the routing tables within the area. Ineffect,the no-summary keyword makes the NSSA totally stubby.

QUESTION: 55The Company multi-protocol WAN is shown below:

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In this network, routers Company2, Company3, Company4, and Company5 have OSPFenabled. What should be configured on the routers in area 1 to ensure that all defaultsummary routes and redistributed EIGRP routes will be forwarded from Company6 to area1, and only a default route for all other OSPF routes will be forwarded from Company5 toarea 1.

A. Company5(config-router)# area 1 nssa no-summaryCompany6(config-router)# area 1 nssaB. Company5(config-router)# area 1 stub no-summaryCompany6(config-router)# area 1 stubC. Company5(config-router)# area 1 nssaCompany6(config-router)# area 1 nssaD. Company5(config-router)# area 1 stubCompany6(config-router)# area 1 stub

Answer: A

Explanation:Not-so-stubby area (NSSA) - An NSSA is an area that is similar to a stub area but allowsfor importingexternal routes as Type 7 LSAs and translation of specific Type 7 LSA routesinto Type 5 LSAsTo configure an OSPF area as a NSSA, configure all OSPF routerinterfaces that belong to the area using thefollowing command syntax:Router(config-router)#area area-id nssa [no- summary]Typically, use the optional keyword no-summarywhen configuring NSSA on an ABR. This prevents Type 3and Type 4 summary routesfrom flooding the NSSA area and minimizes the routing tables within the area. Ineffect,the no-summary keyword makes the NSSA totally stubby.

QUESTION: 56Assuming that you are configuring an ABR in an OSPF area, which IOS command wouldyou execute if your goal was to summarize the networks advertised out of the area?

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A. summary-address address maskB. area area-id range address maskC. auto-summary address mask area area-idD. network network-number wildcard mask area area-idE. None of the other alternatives apply

Answer: B

Explanation:The area area-id range address mask command consolidates IA (intra-area) routes on anABR. This commandinstructs the ABR to summarize routes for a specific area beforeinjecting them into a different area.

Incorrect Answer:A: The summary-address address mask command consolidates external routes (inter-area)on an ASBRC: Auto-summarization is not useful here.D: The network command cannot be used for this purpose. This command is simply usedto add a network tothe OSPF routing process.

QUESTION: 57Which two of the following characteristics are defined by the network command? (Selecttwo)

A. The OSPF area IDB. The OSPF router IDC. The OSPF process IDD. Which interface belongs to which OSPF area

Answer: A, D

Explanation:The network command designates the OSPF area for an interface with the specified IPaddress. Syntax: network address wildcard-mask area area-id

QUESTION: 58When configuring a multi-area OSPF network to summarize routes, what additionalcommand is required by ASBR’s that is not needed by ABR’s?

A. area range command

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B. ospf summarize commandC. aggregate-route commandD. summary-address commandE. None of the other alternatives apply

Answer: D

Explanation:Using this command for OSPF causes an OSPF autonomous system boundary router(ASBR) to advertise oneexternal route as an aggregate for all redistributed routes that arecovered by the address. For OSPF, thiscommand summarizes only routes from otherrouting protocols that are being redistributed into OSPF .

Incorrect Answer:A: The area range command is used only with area border routers (ABRs). It is used toconsolidate orsummarize routes for an area. The result is that a single summary route isadvertised to other areas by theABR.B, C: There are no such commands for OSPF .

QUESTION: 59A Company OSPF router is configured in the following manner: router ospf 200 network203.42.67.0 0.0.0.255 area 7 network 203.42.68.0 0.0.0.255 area 0 area 7 stub no-summaryarea 7 default-cost 30 Which of the following statements are true regarding thisconfiguration? (Select two)

A. Area 7 is a totally stubby area.B. If the backbone becomes discontiguous, traffic can be routed through area 7.C. Redistribution of other routing protocols takes place at the area designated router.D. Area 7 non-ABR routers contain only intra-area routing information and a default route.

Answer: A, D

Explanation:An extension to stub areas is what is called "totally stubby areas". Cisco indicates this byadding a "nosummary"keyword to the stub area configuration. A totally stubby area is onethat blocks external routes andsummary routes (inter-area routes) from going into thearea.Note: The area stub command is used to define an area as a stub area.Syntax: areaarea-id stub [no- summary]The no-summary optional parameter prevents an ABR fromsending summary link advertisements into the stubarea.

Reference:OSPF Design Guidehttp://www.cisco.com/warp/public/104/3.html

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QUESTION: 60Which of the following is an OSPF configuration parameter that is used on an ABR, butnot on an internal router?

A. A virtual link to area 0.B. OSPF summarization command.C. default-cost extension to the area commandD. no-summary extension to the area stub command.E. None of the other alternatives apply

Answer: D

Explanation:The no-summary extension of the area stub command is used only for ABRs connected tototally stubbyareas. It prevents an ABR from sending summary link advertisements intothe stub area. This option is used forcreating a totally stubby area.

Incorrect Answer:A: For a virtual link to work both ends need to be configured.B, C: These commands are not specific to an ABR only.

QUESTION: 61Router Company1 is an OSPF ABR that connects area 3 to the network. You wish toconfigure area 3 to summarize the IP address range 172.16.20.192 – 172.16.20.223. Whichtwo of the following IOS commands would you execute to accomplish this? (Select two)

A. network 172.16.20.192 0.0.0.31 area 3B. area 3 range 172.16.20.192 172.16.20.223C. area 3 range 172.16.20.192 255.255.255.224D. network 172.16.20.192 255.255.255.224 area 3

Answer: A, C

Explanation:A: When configuring multiple OSPF areas, make sure to associate the correct networkaddresses with thedesired area ID . Syntax: network address wildcard-mask area area-id.We must use a wildcard mask (0.0.0.31) and not a network mask (255.255.255.224)C: We must instruct the ABR to summarize routes for a specific area before injecting theminto a differentarea. Syntax: area area-id range address mask

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Incorrect Answer:B: This is the wrong syntax. We should use a network mask to specify the address range.D: We should use a wildcard mask, not a network mask with the network command.

QUESTION: 62Router Company1 is an ABR that is part of the Company OSPF network. Company1 hasbeen configured with the “area range” command. What does this command provide?

A. It provides the range of areas in the OSPF internetwork.B. It provides the range of areas in which this ABR participates.C. It provides a summary of networks to be advertised outside the area.D. It provides a summary of networks outside the area and inside the AS.

Answer: C

Explanation:The area range command creates/deletes an area address range entry and optionallyspecifies whether to advertise the addresses. It is used for summarizing routes into an area.Syntax: [no] area area-id range address mask [do-not-advertise]Description: Addressranges are used to aggregate address ranges from within the area into one singleadvertisement sent into the adjacent areas, or to prevent the advertisement of networks. AnOSPF area is defined as a list of address ranges. Each address range consists of an addressand mask pair. Area range entries are used to aggregate network information before theadvertisements are flooded into the backbone. A single summary LSA is originated foreach range.

QUESTION: 63While performing a routine inspection of your OSPF network you come to the realizationthat the Designated Router (DR) may be overloaded, and you’re considering changing theDR. What are three ways you could manipulate the election of the DR? (Select three)

A. Use of the priority command.B. Use of the router-id command.C. Assignment of the loopback address.D. Assigning a lower IP addressE. By adding additional memory to the desired router.

Answer: A, B, C

Explanation:

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A: The OSPF router priority is only used on multi-access networks such as LAN's. Thisestablishes whether therouter is eligible to become the Designated Router (DR) for theLAN. A priority of zero means that therouter is not eligible to become DR.B: The router ID is used to break ties during the DR and BDR election processes if thepriority values areequal.C: The loopback address is used in DR election. The highest IP address on the router is therouter ID . If aloopback address is configured, then it is the router ID .

Incorrect Answer:D: The highest IP address is used as the router ID, not the lowest.E: This would not make it a more likely DR candidate, did the DR election process doesnot take intoconsideration the amount of memory.

QUESTION: 64The following output was seen on router Company1:

Based on the output shown above, which of the following statements is true?

A. A default route is configured on the local router.B. OSPF router 5.0.0.2 is an ABR.C. The default route is learned from an OSPF neighbor.D. Network 6.0.0.0/8 was learned from an OSPF neighbor within the area.E. None of the other alternatives apply.

Answer: B

Explanation:In this example, the network 6.0.0.0/8 shows that it was leaned via IA, or Inter-area. Sincethis came from a neighbor in a different area, then the neighbor router at 5.0.0.2 must bean ABR. The various route types used by OSPF are:

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QUESTION: 65The Company OSPF network is shown in the following exhibit:

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Study the exhibits shown above carefully. All routers have simultaneously been reloadedand the DR election has concluded as expected. On Company4, what state is routerCompany2 in?

A. 2WAY/BDRB. FULL/BDRC. 2WAY/DROTHERD. 2WAY/DRE. FULL/DROTHERF. FULL/DRG. None of the other alternatives apply

Answer: E

Explanation:How OSPF Forms Its Neighbors: In this example topology, all routers are running OpenShortest Path First (OSPF) over the Ethernet network:

This is sample output of the show ip ospf neighbor command on R7 and R8:R7# show ipospf neighborNeighbor ID Pri State Dead Time Address Interface170.170.3.4 12WAY/DROTHER 00:00:34 170.170.3.4 Ethernet0170.170.3.3 1 2WAY/DROTHER00:00:34 170.170.3.3 Ethernet0170.170.3.8 1 FULL/DR 00:00:32 170.170.3.8Ethernet0170.170.3.2 1 FULL/BDR 00:00:39 170.170.3.2 Ethernet0Notice that R7establishes full adjacency only with the Designated Router (DR) and the BackupDesignatedRouter (BDR). All other routers have a two-way adjacency established. This isnormal behavior for OSPF .In this case, the "show ip ospf neighbor" is performed onCompany4. Companyg4 is the DR (due to higher routerID) so it will have FULLadjacency with all routers including Company2. If the "show ip ospf neighbor" hadbeenperformed on Company1, then it would show 2way/drother withCompany2.Router4#show ip ospf neighborNeighbor ID Pri State Dead Time AddressInterface192.168.1.1 1 FULL/DROTHER 00:00:31 192.168.1.1FastEthernet0/0192.168.1.2 1 FULL/DROTHER 00:00:31 192.168.1.2FastEthernet0/0192.168.1.3 1 FULL/BDR 00:00:31 192.168.1.3FastEthernet0/0Router1#show ip ospf neighborNeighbor ID Pri State Dead Time AddressInterface192.168.1.2 1 2WAY/DROTHER 00:00:35 192.168.1.2

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FastEthernet0/0192.168.1.3 1 FULL/BDR 00:00:35 192.168.1.3FastEthernet0/0192.168.1.4 1 FULL/DR 00:00:35 192.168.1.4 FastEthernet0/0

Reference:www.cisco.com/en/US/customer/tech/tk365/technologies_tech_note09186a0080094059.shtml

QUESTION: 66While troubleshooting some connectivity issues, you issue the “show ip ospf database” inorder to examine the link state database. Which three of the statements below are trueregarding the OSPF link state database? (Select three)

A. Each router has an identical link state database.B. External routes are imported into a separate link state database.C. Synchronization of link state databases is maintained via flooding of LSAs.D. Information in the link state database is used to build a routing table by calculating ashortest- path tree.E. By default, link state databases are refreshed every 10 minutes in the absence oftopology changes.

Answer: A, C, D

Explanation:The Link state database is a collection of link state advertisement for all routers andnetworks. Each router inthe OSPF network maintains an identical database. LSA floodingoccurs whenever there is a change in theOSPF topology, ensuring that the databases aresynchronized. OSPF also uses the SPF algorithm to build thedatabase tables.

Incorrect Answer:B. Only one link state database is maintained, and it is used for all OSPF routes.E. The default refresh time is 30 minutes.

Reference:Building Scalable Cisco Networks (Cisco Press) page 178.

QUESTION: 67Which command should you use to verify what networks are being routed by a givenOSPF process?

A. show ip ospfB. show ip routeC. show ip protocolD. show ip ospf database

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E. None of the other alternatives apply

Answer: C

Explanation:The information displayed by the show ip protocols command is useful in debuggingrouting operations.Information in the Routing Information Sources field of the show ipprotocols output can help you identify arouter suspected of delivering bad routinginformation. For OSPF routers, this command will display the routednetworks.

Incorrect Answer:A: To display general information about Open Shortest Path First (OSPF) routingprocesses, use the show ipospf command in EXEC mode. This command will display theareas assigned and other useful information, butnot the networks beingrouted.Example:Company1# show ip ospfRouting Process "ospf 201" with ID192.42.110.200Supports only single TOS(TOS0) routeIt is an area border and autonomoussystem boundary routerRedistributing External Routes from,igrp 200 with metric mappedto 2, includes subnets in redistributionrip with metric mapped to 2igrp 2 with metricmapped to 100igrp 32 with metric mapped to 1Number of areas in this router is 3Area192.42.110.0Number of interfaces in this area is 1Area has simple passwordauthenticationSPF algorithm executed 6 timesB: This will display the active routing table, but not the networks that are being routed.D: The OSPF database does not display the networks being routed.

QUESTION: 68You have a multi-area OSPF network and you’re concerned because one of the sites ishaving connectivity problem to resources in a different area. Which IOS privileged modecommand would you enter to confirm that your network: A) has a path to its ABR, B) hasa path to its ASBR, and C) the SPF calculation is functional?

A. show ip protocolsB. show running-configC. show ip ospf neighborD. show ip ospf border-routers

Answer: D

Explanation:The show ip ospf border-routers command displays the internal OSPF routing table entriesto an area borderrouter (ABR) and autonomous system boundary router (ASBR). The SPFNo in the output is the internalnumber of SPF calculation that installs thisroute.Example:RouterCompany# show ip ospf border-routersOSPF Process 109 internalRouting TableDestination Next Hop Cost Type Rte Type Area SPF No160.89.97.53144.144.1.53 10 ABR INTRA 0.0.0.3 3160.89.103.51 160.89.96.51 10 ABR INTRA

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0.0.0.3 3160.89.103.52 160.89.96.51 20 ASBR INTER 0.0.0.3 3160.89.103.52144.144.1.53 22 ASBR INTER 0.0.0.3 3

Incorrect Answer:A: The show ip protocols command only displays routing protocol parameters and currenttimer values.B: The show running-config command displays the currently used configuration mode.The requiredinformation will not be displayed.C: The show ip ospf neighbor command displays OSPF-neighbor information on a per-interface basis. It doesnot include ABR, ASBR or SPF information.

QUESTION: 69An OSPF link can be in multiple states at any given moment (ie. Exstart, exchange, full).Which two IOS commands let you view the state of the link? (Select two)

A. show ip ospfB. show ip protocolsC. show ip ospf neighborD. show ip ospf interface

Answer: C, D

Explanation:The link state exstart is an OSPF link state (see note below). We need retrieve OSPF linkstate information.C: The output of the show ip ospf neighbor command is used To display OSPF- neighborinformation on aper-interface basis. It includes link state information.D: The show ip ospf interface command is used to display OSPF-related interfaceinformation for a particularinterface. This includes the link state of the specified interface.Note: exstart state: After two OSPF neighboring routers establish bi-directionalcommunication and completeDR/BDR election (on multi-access networks), the routerstransition to the exstart state.

Incorrect Answer:A: The show ip ospf command is used to display general information about OSPF routingprocesses. However,it does not include any link state information.B: The command "show ip protocols" displays the parameters and current state of theactive routing protocolprocess. It does not show any link state information.

QUESTION: 70Which command would display OSPF parameters such as filters, default metric, maximumpaths, and number of areas configured on a router?

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A. show ip protocolB. show ip routeC. show ip ospf interfaceD. show ip ospfE. show ip interfaceF. None of the other alternatives apply

Answer: A

Explanation:The “show ip protocol” command displays values about routing timers and networkinformation associated with the entire router. This includes, the AS number associatedwith the routing process, number of areas configured on the router, the metric, and themaximum paths.

QUESTION: 71Exhibit:

You work as a network technician at Company.com. You trainee Tess King shows you theIOS command output displayed in the exhibit. What command did Tess use to produce thisoutput?

A. show ip RIPB. show ipv6 ospf

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C. show ip ospfD. show ip ospf interfaceE. show ipv6 ospf interfaceF. show ipv4 ospfG. None of the other alternatives apply

Answer: B

Explanation:In this case we can see that OSPFv3 is being used, and since OSPFv3 is used exclusivelyfor IPv6 networks weknow that the correct answer must be "show ipv6 OSPF ." To displaygeneral information about Open ShortestPath First (OSPF) routing processes, use the showipv6 ospf command in user EXEC or privileged EXECmode.Example:The following issample output from the show ipv6 ospf command:Router# show ipv6 ospfRouting Process"ospfv3 1" with ID 10.10.10.1SPF schedule delay 5 secs, Hold time between two SPFs 10secsMinimum LSA interval 5 secs. Minimum LSA arrival 1 secsLSA group pacing timer240 secsInterface flood pacing timer 33 msecsRetransmission pacing timer 66msecsNumber of external LSA 0. Checksum Sum 0x000000Number of areas in this routeris 1. 1 normal 0 stub 0 nssaArea BACKBONE(0)Number of interfaces in this area is1MD5 Authentication, SPI 1000SPF algorithm executed 2 timesNumber of LSA 5.Checksum Sum 0x02A005Number of DCbitless LSA 0Number of indication LSA0Number of DoNotAge LSA 0Flood list length 0

Reference:http://www.cisco.com/en/US/docs/ios/12_3t/ipv6/ipv6_15g.html#wp2139460

QUESTION: 72Which IOS command would you use to find out which networks are routed by a particularOSPF process?

A. show ospfB. show ip routeC. show ip protocolsD. show ip ospf databaseE. None of the other alternatives apply

Answer: C

Explanation:The show ip protocols command display current routing protocols. It displays theparameters and current stateof the active routing protocol process. The output includes alist of the networks routing for individual ospfprocesses.Sample output:RtCompany# showip protocolsRouting Protocol is "ospf 200"Sending updates every 0 secondsInvalid after 0seconds, hold down 0, flushed after 0Outgoing update filter list for all interfaces is not

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setIncoming update filter list for all interfaces is not setRedistributing: ospf 200Routing forNetworks:172.6.31.5/32Routing Information Sources:Gateway Distance LastUpdateDistance: (default is 110)

Incorrect Answer:A: The show ospf command displays summary information regarding the global OSPFconfiguration.B: The show ip route command displays the IP routing table.D: The show ip ospf database command displays the contents of the topological databasemaintained by therouter. The command also shows the router ID and the OSPF process ID.However, the output does notinclude the networks routing for individual ospf processes.

QUESTION: 73Routers Company1, Company2, and Company3 are part of OSPF area 100 as shownbelow:

In the Company network shown above, router Company1 was elected the DR andCompany2 was elected the BDR. Assume that Company1 fails, and that Company2 takesthe place of the DR while Company3 becomes the new BDR. What will happen whenCompany1 comes back online?

A. Company1 will take the place of DR immediately upon establishing its adjacencies.B. Company1 will take the place of DR only if Company2 fails.C. Company1 will take the place of DR only if both Company2 and Company3 fail.D. A new election will take place establishing an all new DR and BDR based onconfigured priority levels an MAC addresses.

Answer: C

Explanation:If a router with a higher priority value gets added to the network, it does not preempt theDR and BDR. Theonly time a DR and BDR changes is if one of them is out of service. If

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the DR is out of service, the BDRbecomes the DR, and a new BDR is selected. If the BDRis out of service, a new BDR is elected. In a multiaccessnetwork, the router that is poweredon first will generally become the DR, since the DR/BDR process isnot pre-emptive.

Reference::CCNP Self-Study Second Edition P.243

QUESTION: 74The Company OSPF network is shown in the diagram below:

Which type of Link State Announcement will CompanygE use to announce changes innetwork 22 to Area 1?

A. Type 1 LSAB. Type 2 LSAC. Type 3 LSAD. Type 4 LSAE. Type 5 LSA

Answer: E

Explanation:

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The external link LSA is originated by AS boundary routers and is flooded throughout theAS. Each external advertisement describes a router to a destination in another autonomoussystem. Default routes for the AS can also be described by AS external advertisements.This is identified as a Type 5 LSA.

QUESTION: 75Which three conditions can cause BGP neighbor establishment to fail? (Select three)

A. There is an access list blocking all TCP traffic between the two BGP neighbors.B. The EBGP neighbor is not directly connected, and the ebgp-multi-hop option is set tothe default value.C. The IBGP neighbor is not directly connected.D. BGP synchronization is enabled in a Transit AS with fully-meshed IBGP neighbors.E. The BGP update interval is different between the two BGP neighbors.F. The BGP neighbor is referencing an incorrect AS number in its neighbor statement.

Answer: A, B, F

Explanation:BGP uses TCP port 179 to establish and maintain neighbor relationships, so any accesslists or firewalls mustpermit this port for BGP to function.By default, EBGP multi-hop isnot enabled, so the EBGP peer must be directly connected in order for the localBGP routerto know how to reach the EBGP peer.BGP uses neighbor statements that specify the ASnumber of the BGP peer. If it is the same number as thelocal BGP router process, then theBGP router knows that IBGP is used. If the AS number for the specifiedpeer is different,then EBGP is used. Either way, the specified neighbor must be configured correctly, ortheBGP peers will not become neighbors.

QUESTION: 76The router that is being used for the Internet is low on memory. Because multiple ISP’s arebeing used, BGP is needed for Internet routing. Which of the following types of routesshould be received from the Internet providers if the goal is to consume as little memory aspossible?

A. Only default routes.B. Only partial BGP routes.C. Only internal BGP routes.D. Only redistributed routes.E. All routes

Answer: A

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Explanation:Today, the Internet consists of over 100,000 routes, so accepting the full routing table froman ISP can consumea great deal of router memory. By only accepting default routes fromthe ISPs ensures a minimal impact on thesystem. There is no risk of having yourautonomous system (AS) becoming a transit AS. By receiving onlydefault routes, theentire Internet will be reachable while only using a small amount of memory for theroutingtable.Note: One recommendation of Cisco, not listed here, is to use AS_PATHfilters for accepting only routesoriginated from an ISP and its directly connectedAutonomous Systems (AS), instead of receiving the full BGProuting table from an ISP.

Reference:Achieve Optimal Routing and Reduce BGP Memory Consumptionhttp://www.cisco.com/warp/public/459/41.shtml

QUESTION: 77Which BGP state is a router in when it has found the IP address in the neighbor statementand has created and sent out a BGP packet but the router has not received a response back?

A. UpdateB. ConnectC. ActiveD. Established

Answer: B

Explanation:The following table describes the various states that a BGP router can be in:BGP StateMachineBGP goes through six states to establish an adjacency.Idle - incoming connectionsare refused, and the system gets ready to start speaking BGP. After this is done (byway ofa Start event), move to Connect.Connect - a connection is made to the peer. Send a BGPOPEN message, and go to OpenSent.Active - a connection comes in from a peer. Send aBGP OPEN message, and go to OpenSent.OpenSent - Wait for an OPEN message fromthe peer. When received, send a KEEPALIVE and go toOpenConfirm.OpenConfirm -Wait for the KEEPALIVE from the peer, then move to Established.Established -Bidirectional communication is established. Start sending UPDATE and KEEPALIVEmessagesas required

QUESTION: 78You need to enable BGP within your enterprise network. Which two statements are trueregarding BGP? (Select two)

A. BGP is designed to scale only to large companies.B. The UDP protocol is used for speed and low overhead.

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C. BGP will never send a message unless it is triggered update.D. The TCP protocol is used for reliability.E. BGP is a path vector routing protocol.F. BGP is a distance vector routing protocol.

Answer: D, E

Explanation:BGP routers exchange network reachability information, called path vectors, made up ofpath attributes. Thepath-vector information includes a list of the full path of BGPautonomous system numbers (hop by hop)necessary to reach a destination network and thenetworks that are reachable at the end of the pathBGP uses TCP as its transport protocol,which provides connection- oriented reliable delivery. BGP assumesthat itscommunication is reliable; therefore, it does not have to implement retransmission or errorrecoverymechanisms. BGP uses TCP port 179.

QUESTION: 79Every routing protocol has a loop prevention mechanism. Which BGP attribute is used byBGP routers to prevent routing loops?

A. OriginB. WeightC. AS-pathD. Next-hopE. Local preferenceF. MEDG. None of the other alternatives apply

Answer: C

Explanation:An AS_Path attribute is a well-known mandatory attribute, type code 2. It is the sequenceof AS numbers that aroute has traversed to reach a destination. The AS that originates theroute adds its own AS number whensending the route to its external BGP peers.Thereafter, each AS that receives the route and passes it on to otherBGP peers willprepend its own AS number to the list. Prepending is the act of adding the AS number tothebeginning of the list. The final list has all the AS numbers that a route has traversedwith the AS number of theAS that originated the route at the end of the list. This type ofAS_Path list is called an AS_Sequence becauseall the AS numbers are orderedsequentially.BGP uses the AS_Path attribute as part of the routing updates, update packet,to ensure a loop free topology onthe Internet. Each route that gets passed between BGPpeers will carry a list of all AS numbers that the route hasalready been through. If the routeis advertised to the AS that originated it, that AS will see itself as part of theAS_Pathattribute list and will not accept the route. BGP speakers prepend their AS numbers when

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advertisingrouting updates to other autonomous systems, external peers. When the route ispassed to a BGP speaker withinthe same AS, the AS_Path information is left intact.

QUESTION: 80You need to determine if you should implement BGP routing within your enterprise.Implementing this routing protocol in an AS (Autonomous System) is most appropriatewhen? (Select 3)

A. An AS has multiple connections to other autonomous systems.B. The Intranet is limited to a single connection to the Internet or another AS.C. Routing policy and route selection for traffic entering and leaving the AS must bemanipulated.D. An AS allows packets to transit through it to reach other autonomous systems.E. There is sufficient memory and processor power to handle to the constant updates.,F. An AS needs to dynamically establish adjacencies with unspecified neighbors.

Answer: A, C, E

QUESTION: 81There are numerous attributes associated with BGP. Which BGP attribute will not beadvertised in routing updates to its neighboring routers?

A. Local preferenceB. Next hopC. OriginD. WeightE. AS_pathF. None of the other alternatives apply

Answer: D

Explanation:The Weight attribute is similar to the Local Preference attribute in that it gives higherpreference to the routethat has a higher weight. The difference is that the weight parameteris local to the router and is not exchangedbetween routers. The weight parameterinfluences routes coming from different providers to the same router,one router withmultiple connections to two or more providers. The weight parameter has a higherprecedencethan any other attribute. It is the most important attribute when determiningroute preference. The weightattribute is a Cisco proprietary attribute, and does not apply toother vendors such as Juniper.

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QUESTION: 82Company uses BGP to advertise their IP blocks to the Internet. Which statement is trueabout EBGP?

A. EBGP requires a full mesh.B. An internal routing protocol can be used to reach an EBGP neighbor.C. A static route can be used to form an adjacency between neighbors.D. The next hop does not change when BGP updates are exchanged between EBGPneighbors.E. None of the other alternatives apply.

Answer: C

Explanation:Only choice C is correct. To reach a EBGP peer, a static route can be used with the EBGPmulti-hop commandto establish a neighbor adjacency. Unlike interior routing protocols,EBGP neighbors do not need to physicallybe connected to each other. All that is needed isa path to the peer IP address, and a valid TCP port 179connection between the BGProuters.

QUESTION: 83All of the IBGP routers in the Company network have peer relationships built with everyother IBGP router in the Company network. Why should iBGP sessions be fully meshedwithin a Transit AS?

A. Routes learned via EBGP are never propagated to other IBGP peers.B. Routes learned via IBGP are never propagated to other IBGP peers.C. A full mesh allows for optimal routing within the Transit AS.D. Routes learned via IBGP are never propagated to other EBGP peers.E. BGP requires redundant TCP sessions between IBGP peers.F. None of the other alternatives apply.

Answer: B

Explanation:Any two routers that have formed a TCP connection in order to exchange BGP routinginformation are calledpeers or neighbors. It is important to remember that the BGP peerswill never become established unless there isIP connectivity between the two peers.BGPdoes not advertise routes learned by way of IBGP peers to other IBGP peers. If BGP did,BGP routinginside the AS would present a dangerous potential for routing loops. ForIBGP routers to learn about all BGProutes inside the AS, they must connect to every otherIBGP router in a full IBGP mesh. This full mesh needs tobe only logical, not physical. In

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other words, as long as the IBGP peers can connect to each other using TCP/IP,a logicalfull mesh can be created even if the routers are not directly connected.

QUESTION: 84The Company BGP network is shown below:

By default, when Company2 passes BGP advertisements from Company1 about network192.168.2.0 to Company3, what address will be listed as the next-hop address?

A. 10.1.1.2B. 10.1.1.1C. 192.168.1.49D. 192.168.1.50E. None of the other alternatives apply

Answer: D

Explanation:The next hop attribute is a well-known mandatory attribute, type code 3. In terms of anIGP, such as RIP, the"next hop" to reach a route is the IP address of the router that hasannounced the route.The next hop concept with BGP is more complex and takes one of thefollowing three forms: For EBGP sessions, the next hop is the IP address of the neighborthat announced the route. For IBGP sessions, where routes originated inside the AS, thenext hop is the IP address of the neighborthat announced the route. For routes injected intothe AS by way of EBGP, the next hop learned fromEBGP is carried unaltered into IBGP.The next hop is the IP address of the EBGP neighbor from whichthe route was learned.When the route is advertised on a multiaccess medium,such as Ethernet or Frame Relay,the next hop isusually the IP address of the interface of the router. This will be theinterface connected to the media thatoriginated the route.

QUESTION: 85

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Which three of the statements below correctly describe the characteristics of AutonomousSystems in routed networks? (Select three)

A. Within an AS, all routers must run either BGP or IBGP.B. An AS uses exterior gateway protocols (EGPs) to exchange information with otherautonomous systems.C. An AS is a group of routers under the same technical administration.D. Within an AS, routes learned through BGP can be redistributed using interior gatewayprotocols.E. Within an AS, routes learned through an interior protocol cannot be redistributed usingBGP to other autonomous systems.

Answer: B, C, D

Explanation:Exterior Gateway Protocol (EGP) routing protocol used to connect between autonomoussystems.o The use of the term autonomous system in connection with BGP stresses thefact that the administrationof an autonomous system appears to other autonomous systemsto have a single coherent interior routingplan, and presents a consistent picture of thosenetworks that are reachable through it.o BGP is used between autonomous systems

Incorrect Answer:A: Within an AS, all routers need not run either interior BGP or exterior BGP. While allIBGP peers need tobe fully meshed, all routers within the network do not need to run BGP.E: One of the major reasons for running BGP is so that the interior public IP networkswithin an AS can bedistributed to other systems in the Internet via BGP.


QUESTION: 86The Company network is displayed in the following diagram:

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On the assumption that there is no IGP running in AS 64700 and synchronization is OFF,which router in AS 64700 is going to advertise the route to 183.32.0.0?

A. Company2 onlyB. Company5 onlyC. Company2 and Company5 onlyD. Company2, Company3, and Company4 onlyE. Company2, Company3, Company4, and Company5

Answer: A

Explanation:BGP needs to establish a TCP session from it's neighbors in order to exchange routes andform a neighborrelationship to exchange updates. This applies to IBGP and EBGP. Thereis no route from Company2 to Company4 norCompany5 to Company3. Because of this,only Company2 will be able to advertise the route to Company1.

QUESTION: 87Which of the following statements about IBGP routers are true? (Select one)

A. They must be fully meshed.B. They can be in a different AS.C. They must be directly connected.D. They do not need to be directly connected.E. All of the above

Answer: D

Explanation: Since BGP runs over TCP, the IBGP speakers need to only be able to reachthe other IBGP speakers via a TCPconnection across the network and do not need to bedirectly connected. Even if two IBGP neighbors areseparated by other routers, they willstill become neighbors as long as they are reachable via TCP.

Incorrect Answer:A: Within an AS, all IBGP speakers must be configured as a full mesh. The onlyexceptions to this rule occurwhen router reflection or confederations are used.B: IBGP routers need to be configured with the same AS number. The only exception tothis rule is when BGPconfederations are in use.C: The routers only need to be reachable via a TCP connection.

QUESTION: 88

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Router Company1 is configured as a route reflector. What would happen if routerCompany1 would receive an update from a peer in a different autonomous system?

A. It discards the update.B. It sends the update to all IBGP peers.C. It sends the update only to non clients.D. It sends the update only to route reflector clients.E. It sends the update to all routers in the autonomous system.

Answer: B

Explanation:When any BGP router receives an update from an EBGP peer, it will forward this routinginformation to allIBGP peers. This is true for all EBGP routers, including route reflectors.

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_configuration_guide_chapter09186a00800ca571.html#5155

QUESTION: 89Which of the following statements is true about BGP peer communications?

A. Communication between BGP peers runs over RIP.B. Communication between BGP peers runs over TCP.C. Communication between BGP peers runs over UDP.D. Communication between BGP peers runs over ICMP.

Answer: B

Explanation:BGP communicate through a TCP connection. TCP port 179 is reserved for BGP sessions.

Reference:Border Gateway Protocolhttp://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/bgp.htm

QUESTION: 90The Company BGP network is shown in the diagram below:

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Router Company1 receives BGP routing advertisements from router Company2 about thenetwork 165.50.0.0. By default, what is the value of the next hop attribute in this multi-access network?

A. 40.1.1.1B. 40.1.1.2C. 40.1.1.3D. Router Company1 does not accept the advertisement from Router Company2 becauseRouter Company1 is not peering with Router Company3 via BGP.E. Router Company2 does not advertise network 165.50.0.0 to Router Company1 becausethe network is not directly connected to Router Company2.

Answer: B

Explanation:In this particular scenario BGP routes are learned from the 40.1.1.0 network, which meansall the Company routers are in the same multi-access network. In the normal situationsrouter Company1 would get Company2’s IP address as the next hop address, but in thisparticular scenario this process would unnecessarily add an extra hop to the path, so bydefault Company3’s interface will be next hop. See the example below from Cisco.Example: BGP Next Hop (Multiaccess Networks)

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This example shows how the next hop behaves on a multiaccess network such asEthernet.Assume that RTC and RTD in AS300 run OSPF . RTC runs BGP with RTA.RTC can reach network 180.20.0.0via 170.10.20.3. When RTC sends a BGP update toRTA with regard to 180.20.0.0, RTC uses as next hop170.10.20.3. RTC does not use itsown IP address, 170.10.20.2. RTC uses this address because the networkbetween RTA,RTC, and RTD is a multiaccess network. The RTA use of RTD as a next hop to reach180.20.0.0is more sensible than the extra hop via RTC.Note: RTC advertises 180.20.0.0 toRTA with a next hop 170.10.20.3.

Reference:http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800c95bb.shtmlCisco Press BSCI Quick Reference Sheets, page 51.

QUESTION: 91A problem was reported that the 10.10.10.0/24 prefix was not injected into the local BGPtable on a Company router named Company1. The following information is available fromthis router: Company1 Configuration: router bgp 65001 network 10.0.0.0 neighbor172.16.1.1 remote-as 65002 no auto-summary Routing table information: show ip route |include 10 O 10.10.10.0/24 [110/11] via 192.168.1.1, 2d00h, Ethernet0/0 Why is thisprefix not in the local BGP table of the Company1?

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A. The 172.16.1.1 neighbor is down.B. The prefix 10.10.10.0/24 is not a 'connected' route.C. This route is not a BGP learned route.D. The network command is wrong.E. None of the other alternatives apply

Answer: D

Explanation:The network command is used with IGPs, such as RIP, to determine the interfaces onwhich to send andreceive updates. The command also indicates which directly connectednetworks to advertise. However, whenconfiguring BGP, the network command does notaffect what interfaces BGP runs on. Therefore, configuringjust a network statement willnot establish a BGP neighbor relationship. This is a major difference betweenBGP andIGPs. The network statement follows this syntax:Router(config-router)#network network-number [mask network-mask]In BGP, the network command tells the BGP process whatlocally learned networks to advertise. The networkscan be connected routes, static routes,or routes learned by way of a dynamic routing protocol, such as RIP.These networks mustalso exist in the routing table of the local router or they will not be sent out in updates.Themask keyword can be used with the network command to specify individual subnets.Routes learned by theBGP process are propagated by default but are often filtered by arouting policy. In this example, the correctsyntax should be "network 10.10.10.0 mask255.255.255.0" under the BGP routing process. Without thecorrect subnet mask specified,the route will not get injected into the BGP routing table, even if it is learned viaan IGP. Inthis case, the route is known via OSPF .

QUESTION: 92Observe the diagram shown below:

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In this network, Company3 is the hub router and Company1 and Company2 are thespokes. There are no virtual circuits between the spoke locations. What is needed tosuccessfully route traffic to the 11.11.11.0/24 network from Company1?

A. The neighbor 10.10.10.1 next-hop-self command on Company2.B. The neighbor 10.10.10.1 next-hop-self command on Company1.C. The neighbor 10.10.10.1 next-hop-self command on Company3.D. Nothing is required. This is the default behavior on this topology.E. None of the other alternatives apply.

Answer: C

Explanation:Refer to the following example:BGP Next Hop (NBMA)

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The common medium appears as a cloud in the diagram. If the common medium is aframe relay or any NBMAcloud, the exact behavior is as if you have connection viaEthernet. RTC advertises 180.20.0.0 to RTA with anext hop of 170.10.20.3.The problem isthat RTA does not have a direct permanent virtual circuit (PVC) to RTD and cannot reachthenext hop. In this case, routing fails.The next-hop-self command remedies thissituation.next-hop-self CommandFor situations with the next hop, as in the BGP Next Hop(NBMA) example, you can use the next-hop-selfcommand. The syntax is: neighbor {ip-address | peer-group-name} next-hop-selfThe next-hop-self command allows you to forceBGP to use a specific IP address as the next hop.For the BGP Next Hop (NBMA)example, this configuration solves the problem:RTC#router bgp 300neighbor 170.10.20.1remote-as 100neighbor 170.10.20.1 next-hop-selfRTC advertises 180.20.0.0 with a nexthop equal to 170.10.20.2.

Reference:http ://www.cisco.com/warp/public/459/bgp-toc.html#bgpnexthop

QUESTION: 93Routers Company1 and Company2 are configured as BGP peers. Which of the followingis true regarding this peering relationship? (Select two)

A. Periodic keepalives are used to verify connectivity.B. Incremental keepalives are used to verify connectivity.C. TCP provides a reliable connection between two BGP routers.D. It provides a “best effort” connection between two BGP routers.

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Answer: A, C

Explanation:A: The default keepalive frequency is 60 seconds.C: BGP peering provides a reliableconnection between BGP routers. BGP utilizes the inherent reliability ofTCP, since allBGP sessions are maintained over TCP port 179.

Incorrect Answer:B: Keepalives messages are not incremental.D: BGP peers form a reliable connection.

Reference:BGP Peer Groupshttp://www.cisco.com/warp/public/459/29.html

QUESTION: 94A Company BGP router is configured as shown below: router bgp 65111 neighbor172.16.1.1 remote-as 65111 neighbor 172.16.2.1 remote-as 65112 network 192.168.0.0network 10.0.0.0 ! ip route 192.168.0.0 255.255.0.0 null0 The 192.168.0.0 network is notbeing propagated throughout the network. Based on the information shown above what isthe reason the 192.168.0.0 route is not being advertised?

A. The network 10.0.0.0 statement is missing mask 0.255.255.255.B. The network 192.168.0.0 statement is missing mask 0.0.255.255.C. The network 10.0.0.0 statement is missing mask 255.0.0.0.D. The network 192.168.0.0 statement is missing mask 255.255.0.0E. The auto-summary configuration is missing.

Answer: D

Explanation:The network command is used with IGPs, such as RIP, to determine the interfaces onwhich to send andreceive updates. The command also indicates which directly connectednetworks to advertise. However, whenconfiguring BGP, the network command does notaffect what interfaces BGP runs on. Therefore, configuringjust a network statement willnot establish a BGP neighbor relationship. This is a major difference betweenBGP andIGPs. The network statement follows this syntax: Router(config-router)#network network-number [mask network-mask]In BGP, the network command tells the BGP process whatlocally learned networks to advertise. The networkscan be connected routes, static routes,or routes learned by way of a dynamic routing protocol, such as RIP.These networks mustalso exist in the routing table of the local router or they will not be sent out in updates.Themask keyword can be used with the network command to specify individual subnets.Routes learned bythe BGP process are propagated by default but are often filtered by arouting policy

QUESTION: 95

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Router Company1 is configured for BGP and peering with other BGP routers has beenestablished. During the BGP configuration on this router, the command “aggregate-address173.33.0.0 255.255.252.0” was issued. However, the peers do not receive this aggregatenetwork in BGP advertisements. Also, the router does not have this aggregate network inits BGP table. Which option indicates a possible reason this command did not cause therouter to advertise the aggregate network to its peers?

A. The next hop IP address must be a loopback address.B. Interface NULL 0 is likely shutdown.C. The IGP running on this router does not have network 173.33.0.0/22 installed.D. The BGP command no synchronization is missing.E. Subnets of 173.33.0.0/22 do not exist in the BGP table.F. The BGP command no auto-summary is missing.

Answer: E

Explanation:BGP allows the aggregation of specific routes into one route using the "aggregate- addressaddress mask"command. Aggregation applies to routes that exist in the BGP routingtable.This is in contrast to the networkcommand, which applies to the routes that exists inIP routing table. Aggregation can be performed if at leastone or more of the specific routesof the aggregate address exist in the BGP routing table.

Reference:http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800945ff.shtml

QUESTION: 96A Company BGP router is configured as shown below:

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Examine the above configuration. What does the route map named test accomplish in thisconfiguration?

A. It permits only the 10.0.0.0/8 prefix to be received from the 10.1.1.1 neighborB. It marks all prefixes received from the 10.1.1.1 neighbor with a MED of 200C. It marks the 10.0.0.0/8 prefix received from the 10.1.1.1 neighbor with a MED of 200D. It marks the 10.0.0.0/8 prefix advertised to the 10.1.1.1 neighbor with a MED of 200E. It marks all prefixes advertised to the 10.1.1.1 neighbor with a MED of 200F. It permits only the 10.0.0.0/8 prefix to be advertised to the 10.1.1.1 neighbor

Answer: D

Explanation:The Multiple-exit-discriminator (MED) attribute is an optional nontransitive attribute, typecode 4. MEDinforms external neighbors about the preferred path into an AS that hasmultiple entry points. A lower MED ispreferred over a higher MED.Unlike LocalPreference, the MED attribute is exchanged between autonomous systems, but a MEDattributethat comes into an AS does not leave the AS. When an update enters the AS with acertain MED value, thatvalue is used for decision making within the AS. When BGPforwards the routing update to another AS, theMED is reset to zero. This is true unless theoutgoing MED is set to a specific value.Example:RTB(config)#route-map setmedoutpermit 10RTB(config-route-map)#set metric 50RTB(config)#router bgp 400

QUESTION: 97The command “bgp always-compare-med” was added to router Company1. What will thiscommand accomplish?

A. It forces Company1 to compare the communities of routes from different autonomoussystemsB. It forces Company1 to compare the weight of routes from different autonomous systemsC. It forces Company1 to compare metrics of routes from different autonomous systemsD. It forces Company1 to compare the local preference of routes from differentautonomous systemsE. None of the other alternatives apply

Answer: C

Explanation:

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The Multiple-exit-discriminator (MED) attribute is an optional nontransitive attribute, typecode 4. MEDinforms external neighbors about the preferred path into an AS that hasmultiple entry points. A lower MED ispreferred over a higher MED.Unlike LocalPreference, the MED attribute is exchanged between autonomous systems, but a MEDattributethat comes into an AS does not leave the AS. When an update enters the AS with acertain MED value, thatvalue is used for decision making within the AS. When BGPforwards the routing update to another AS, theMED is reset to zero. This is true unless theoutgoing MED is set to a specific value.Example:RTB(config)#route-map setmedoutpermit 10RTB(config-route-map)#set metric 50RTB(config)#router bgp 400If the bgpalways-compare-med router configuration command is enabled, all paths are fullycomparable,including those from other autonomous systems in the confederation, even ifthe bgp deterministic medcommand is also enabled.

QUESTION: 98According to Cisco’s official best practice recommendations, what is the preferred methodfor populating the BGP table on your router with IGP routes?

A. Use the network command.B. Redistribute EBGP routes into BGP.C. Redistribute dynamic routes into BGP.D. Redistribute static routes into the IGP.E. None of the other alternatives apply

Answer: A

Explanation:For BGP the network command allows BGP to advertise a network that is already in the IPtable.Note: An alternate solution, not listed here, is to redistribute the IGP routes into BGP.

Incorrect Answer:B: We want to distribute internal routes into BGP, not external routes.C: Redistribution from the IGP is NOT advised because there is a great reliance on the IGPtable. It couldcause instability.D: We want to populate the BGP table, not the IGP table.

QUESTION: 99Your network has 2 separate T1 connections with two different providers. To support this,BGP is being configured. The required information regarding the ISPs is shown below:Your network:164.67.36.0/24 YourAS number: 300AS number of ISP1: 1005

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AS number of ISP2: 1010Based on the information provided, which of the following commands would you enter toadvertise your network to ISP1 and ISP2 via BGP?

A. router bgp 1005network 164.67.36.0 mask 255.255.255.0neighbor 15.1.1.1 remote-as 1005neighbor 25.1.1.1 remote-as 1010B. router bgp 300network 164.67.36.0 mask 255.255.255.0neighbor 15.1.1.1 remote-as 1005neighbor 25.1.1.1 remote-as 1010C. router bgp 300network 164.67.36.0neighbor 15.1.1.1 remote-as 1005neighbor 25.1.1.1 remote-as 1010D. router bgp 1010network 164.67.36.0neighbor 15.1.1.1 remote-as 1005neighbor 25.1.1.1 remote-as 1010

Answer: B

Explanation:Step 1: router bgp 300The router bgp command is used to activate the BGP protocol andidentify the local autonomous system.Step 2: network 164.67.36.0 mask 255.255.255.0Thenetwork command controls which networks are originated by this router.Syntax: networknetwork-number network-maskStep 3:neighbor 15.1.1.1 remote-as 1005neighbor 25.1.1.1remote-as 1010The neighbor remote-as command is used to identify a peer router withwhich the local router will establish asession.

Incorrect Answer:A, D: We must specify the local autonomous system in the router bgp command. We mustuse AS 300, not AS1005 or AS 1010C: Both the network number and the network mask must be specified with the networkcommand.

QUESTION: 100You wish to permit all BGP prefixes between /10 and /18 for the 207.0.0.0 network. Howshould a BGP prefix list be configured to do this?

A. ip prefix-list 207.0.0.0/8 ge 10 le 18B. ip prefix-list 207.0.0.0/8 ge 18 le 10

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C. ip prefix-list 207.0.0.0/24 ge 10 le 18D. ip prefix-list 207.0.0.0/24 ge 18 le 10E. None of the other alternatives apply

Answer: A

Explanation:With prefix lists, the “ge” means “greater than or equal to” while the le means “less than orequal to.” Here, we want to specify all prefixes greater than or equal to 10 and less than orequal to 18 as specified in choice A. In addition, we must specify an 8 bit network mask,not a 24 bit network mask.

QUESTION: 101The Company BGP router is configured as shown below:router bgp 64000neighbor 172.16.1.1 remote-as 64000neighbor 10.1.1.2 remote-as 64550network 200.52.1.192 mask 255.255.255.224no synchronizationaggregate-address 200.52.1.0 255.255.255.0The BGP peers 172.16.1.1 and 10.1.1.2 in the above configuration are established andworking, as well as the interface with IP address 200.52.1.192. Based on this information,which statement below is true about your configuration?

A. Router TestK has an IBGP connection with neighbor 10.1.1.2.B. Router TestK has an EBGP connection with the neighbor 172.16.1.1.C. Router TestK advertises only a route 200.52.1.0 255.255.255.0 in BGP.D. Router TestK advertises only a route 200.52.1.192 255.255.255.224 in BGP.E. Router TestK advertises both the routes to 200.52.1.0 255.255.255.0 and 200.52.1.192255.255.255.224 in BGP.F. None of the other alternatives apply

Answer: E

Explanation:The aggregate route, 200.52.1.0 255.255.255.0, and the more specific route, 200.52.1.192255.255.255.224, willboth be advertised. To only advertise the aggregate route thesummary-only option of the aggregate-addresscommand must be used.Note: Theaggregate-address command is used to create an aggregate, or summary, entry in the BGPtable.

Incorrect Answer:

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A: The neighbor 10.1.1.2 belongs to another autonomous system and is a EBGP neighbor,not an IBGPneighbor.B: Router A and neighbor 172.16.1.1 belong to the same autonomous system and is anIBGP neighbor, not anEBGP neighbor.C: The summary-only option of the aggregate-address command is used to only advertisethe summary andnot the specific routes.D: The aggregate route, 200.52.1.0 255.255.255.0, will be advertised as well.

QUESTION: 102While troubleshooting an Internet related problem on the Company network, you enableBGP packet debugging. Which attribute must exist in the BGP update packet?

A. LOCAL_ PREFB. AGGREGATORC. AS_PathD. WeightE. None of the other alternatives apply

Answer: C

Explanation:An AS_Path attribute is a well-known mandatory attribute, type code 2. It is the sequenceof AS numbers that aroute has traversed to reach a destination. The AS that originates theroute adds its own AS number whensending the route to its external BGP peers.Thereafter, each AS that receives the route and passes it on to otherBGP peers willprepend its own AS number to the list. Prepending is the act of adding the AS number tothebeginning of the list. The final list has all the AS numbers that a route has traversedwith the AS number of theAS that originated the route at the end of the list. This type ofAS_Path list is called an AS_Sequence becauseall the AS numbers are orderedsequentially.BGP uses the AS_Path attribute as part of the routing updates, update packet,to ensure a loop free topology onthe Internet. Each route that gets passed between BGPpeers will carry a list of all AS numbers that the route hasalready been through. If the routeis advertised to the AS that originated it, that AS will see itself as part of theAS_Pathattribute list and will not accept the route. BGP speakers prepend their AS numbers whenadvertisingrouting updates to other autonomous systems, external peers. When the route ispassed to a BGP speaker withinthe same AS, the AS_Path information is left intact.

QUESTION: 103Which IOS command would you enter if you wanted to view a list of IBGP and EBGPneighbor relationships that are configured?

A. show ip bgpB. show ip bgp pathsC. show ip bgp peers

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D. show ip bgp summaryE. show ip bgp protocols

Answer: D

Explanation:The show ip bgp summary command displays the status of all BGP connections.Neighbors withcorresponding AS values will be listed; both interior and external.

Incorrect Answer:A: The show ip bgp command displays routes in the BGP routing table, not the neighbors.B: The show ip bgp paths command is used to display all the BGP paths in the database.However, it does notlist the neighbors.C, E: There is no such command.

Reference:http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/np1_r/1rprt1/1rbgp.htm

QUESTION: 104Based on the “show ip bgp summary” output shown below on router Company1, whichtwo statements are true? (Select two)

A. The BGP session to the 10.2.2.2 neighbor is established.B. The router is attempting to establish a BGP peering session with the 10.1.1.1 neighbor.C. The router is attempting to establish a BGP peering session with the 10.2.2.2 neighbor.D. The BGP session to the 10.3.3.3 neighbor is established.E. The BGP session to the 10.1.1.1 neighbor is established.F. The BGP session to the 10.3.3.3 neighbor is established, but the router has not receivedany BGP routing updates from the 10.3.3.3 neighbor.

Answer: C, E

Explanation:Show ip bgp summary command displays the summary of all BGP connections.The sixstates of the BGP FSM are described as follows: Idle - Idle is the first state of a BGP

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connection. BGP is waiting for a start event. It is normally initiated byan administrator or anetwork event. At the start event, BGP initializes its resources and resets a connectretrytimer. Then it starts listening for a TCP notice that BGP can transition back to Idle fromany other statein case of errors. Connect - In the Connect state, BGP is waiting for the TCPconnection to be completed. If the TCPconnection is successful, the state transitions toOpenSent. If the TCP connection fails, the state transitionsto the Active state, and therouter tries to connect again. If the connect retry timer expires, the state remainsin theConnect state, the timer is reset, and a TCP connection is initiated. In case of any otherevent, initiatedby the system or the administrator, the state returns to Idle. Active - In theActive state, BGP is trying to acquire a peer by initiating a TCP connection. If itissuccessful, it transitions to OpenSent. If the connect retry timer expires, BGP restarts theconnect timer andreturns to the Connect state. While active, BGP is still listening for aconnection that may be initiated fromanother peer. The state may go back to Idle in case ofother events, such as a stop event initiated by thesystem or the operator.In general, aneighbor state that is switching between "Connect" and "Active" is an indicationthatsomething is wrong and that there are problems with the TCP connection. It could bebecause of many TCPretransmissions, or the incapability of a neighbor to reach the IPaddress of its peer. OpenSent - In the OpenSent state, BGP is waiting for an open messagefrom its peer. The open message ischecked for correctness. In case of errors, such as anincompatible version number or an unacceptable AS,the system sends an error notificationmessage and goes back to idle. If there are no errors, BGP startssending keepalivemessages and resets the keepalive timer. At this stage, the hold time is negotiated andthesmaller value is taken. If the negotiated hold time is zero (0), the hold timer and thekeepalive timer are notrestarted.At the OpenSent state, BGP recognizes whether the peerbelongs to the same AS or to a different AS. BGPdoes this by comparing its AS number tothe AS number of its peer. A same AS is an IBGP peer and adifferent AS is an EBGPpeer.When a TCP disconnect is detected, the state falls back to Active. For any othererrors, such as an expirationof the hold timer, BGP sends a notification message with thecorresponding error code. Then it returns to theIdle state. OpenConfirm - While inOpenConfirm state, BGP is waiting for a keepalive or notification message. If akeepalivemessage is received, the state goes to the Established state, and the neighbor negotiationiscomplete. If the system receives an update or keepalive message, it restarts the hold time,assuming that thenegotiated hold time is not zero. If a notification message is received, thestate falls back to Idle. The systemsends periodic keepalive messages at the rate set by thekeepalive timer. In the case of any TCP disconnector in response to any stop event,initiated by the system or the administrator, the state returns to Idle. Inresponse to anyother event, the system sends a notification message with an FSM error code and returnstothe Idle state. Established - Established is the final state in the neighbor negotiation. BGPstarts exchanging updatepackets with its peers. If it is non-zero, the hold timer is restartedat the receipt of an update or keepalivemessage.

QUESTION: 105Which IOS command could you use to verify if a BGP router is or isn’t a route reflector?

A. show ip bgp neighborB. show running-configC. show route-reflector

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D. show route-reflector-clientE. None of the other alternatives apply

Answer: A

Explanation:The show ip bgp neighbor command indicates if a particular neighbor is a route reflectorclient.Note: Route reflectors modify the BGP split horizon rule by allowing therouterconfigured as the route reflector to propagate routes learned by IBGP to otherIBGPpeers.

Incorrect Answer:B: Displaying the current configuration would not be useful in finding information in theroute reflector status.C, D: There are no such commands.

QUESTION: 106The “show ip bgp” command was issued on a Company router as shown below:

Based on the Company2 output, which statement is true?

A. The best path to reach the 192.168.11.0 prefix is via 10.200.200.11.B. The 192.168.11.0 and 192.168.12.0 prefixes were learned via EBGP from the10.200.200.11 and 10.200.200.12 EBGP neighbors.C. The best path to reach the 192.168.11.0 prefix is via both 10.200.200.11 and10.200.200.12; BGP will automatically load balance between the two.D. The best path to reach the 192.168.11.0 prefix is via 10.200.200.12.E. None of the other alternatives apply.

Answer: D

Explanation:The best path to any given destination is noted by the ">" in the IP BGP table. In this case,the best path to192.168.11.0 is via next hop 10.200.200.12 due to the fact that the weight ishigher (101) than the path via thealternative next hop. Weight is a Cisco proprietary

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method for path determination and the weight value is usedabove all other values. Within arouter, the path with the highest weight will be preferred.

QUESTION: 107How many metrics are associated with EIGRP for each route?

A. 3B. 4C. 7D. 5

Answer: D

QUESTION: 108While verifying BGP operation on the Company router, you issue the “show ip bgp”command as shown below: routerCompany>show ip bgpBGP table version is 1046033, local router ID is 198.32.162.100Status codes: s suppressed, d damped, h history, * valid, > best, i – internalOrigin codes: i – IGP, e EGP, ? –incompleteNetwork Next Hop Metric LocPrf Weight Path* > 143.16.0.0 128.214.63.2 0 400 0 200 1* 143.16.0.0 192.208.10.5 0 300 0 300 1* 143.16.0.0 143.16.63.5 0 100 0 200 1* 143.16.0.0 203.250.13.41 0 100 0 500 1From the information above, which path will the network 143.16.0.0 prefer to take to exitthe AS?

A. 128.214.63.2B. 192.208.10.5C. 128.213.63.5D. 203.250.13.41E. All of the above will be used in a round robin fashion.

Answer: A

Explanation:Local preference (LocPref) is a well-known discretionary attribute that provides anindication to routers in theAS about which path is preferred to exit the AS. A path with ahigher local preference is more preferred. In thisscenario the following entry has thehighest local preference value of 400.Network Next Hop Metric LocPrf Weight Path* >128.213.0.0 128.214.63.2 0 400 0 200 1The preferred exit path of the AS is therefore128.214.63.2, as noted by the">" which refers to the best path forthis destination.

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QUESTION: 109What are the two reasons for the appearance of 0.0.0.0 as the next hop for a network whenusing the “show ip bgp” command? (Choose two)

A. The network was originated via redistribution of an interior gateway protocol into BGP.B. The network was defined by a static route.C. The network was learned via IBGP.D. The network was learned via EBGP.E. The network was originated via a network or aggregate command.

Answer: A, E

Explanation:From BGP FAQ on www. cisco.com:Q. What does a next hop of 0.0.0.0 mean in the showip bgp command output?A. A network in the BGP table with a next hop address of 0.0.0.0means that the network is locally originatedvia redistribution of Interior Gateway Protocol(IGP) into BGP, or via a network or aggregate command in theBGP configuration.

Reference:http://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a00800949e8.shtml#two

QUESTION: 110Network Topology Exhibit:

Company2 Exhibit:

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Company3 Exhibit:

You work as a network engineer at Company.com. Study the exhibits carefully. BGP hasbeen configured on the Company routers in the network. However, the IBGP peers inautonomous system 65200 have not converged. In addition, this console message wasgenerated on router TESCompanyING2:*Mar 1 03:09:07.729: %TCP-6-BADAUTH NoMD5 digest from 10.10.23.2(179) to 10.10.23.3(11002) On the basis of the informationthat is provided, what is the cause of the problem?

A. OSPF must be configured with the same MD5 authentication.B. BGP authentication can be used on iBGP peers when the connection is configuredbetween the loopback interfaces.C. BGP authentication can be used on eBGP peers only.D. The password that is used for BGP authentication on both BGP peers in autonomoussystem 65200 must be the same.

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E. None of the other alternatives apply

Answer: D

Explanation:The above log message is relating the invalid MD5 password on neighbor. Both peers needto use the same password for MD5 authentication.


You work as a network engineer at Company.com. You study the exhibit carefully. Whichtwo statements are correct? (Choose two.)

A. All the routes were redistributed into BGP from an IGP.B. All the routes were originated by BGP with the network command.C. All six routes will be installed in the routing table.D. Four routes will be installed in the routing table.E. Two routes will be installed in the routing table.

Answer: A, D

Explanation:Because the AS paths shown all end with a ? we know that all of the routes had beedredistributed into BGP. The four best paths, as noted with the > sign, will all be insertedinto the routing table.

QUESTION: 112

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One of the Company routers is unable to form a neighbor relationship with an externalBGP peer. Which two statements are true about external BGP neighbor relationships?(Select two)

A. EBGP neighbors use TCP port 179 to exchange BGP routing tables.B. the BGP split-horizon rule specifies that routes learned via IBGP are never propagatedto other EBGP peers.C. EBGP neighbors must be in different autonomous systems.D. Static routes or an interior gateway protocol is required between EBGP neighbors.E. When an EBGP neighbor receives an update from another EBGP neighbor, it should notforward the update to other EBGP neighbors.F. Loopback addresses should be used between EBGP neighbors.

Answer: A, C

Explanation:BGP updates are carried using TCP on port 179. In contrast, RIP updates use UDP port520, while OSPF doesnot use a Layer 4 protocol. Because BGP requires TCP, IPconnectivity must exist between BGP peers. TCPconnections must also be negotiatedbetween them before updates can be exchanged. Therefore, BGP inheritsthose reliable,connection-oriented properties from TCP.When BGP is running between routers indifferent autonomous systems, it is called External BGP (EBGP).When BGP is runningbetween routers in the same AS, it is called Internal BGP (IBGP). BGP allows the paththatpackets take to be manipulated by the AS, as described in this module. It is important tounderstand howBGP works to avoid creating problems for your AS as a result of runningBGP.


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Above is the output from the “show ip bgp neighbors” command issued on routerCompany1. What is line 21 stating about the BGP connection?

A. The number of consecutive TCP connections to the specified remote neighborB. The number of total TCP connections that the router hasC. The number of times the router has established a TCP connectionD. The number of neighbors that the router hasE. None of the other alternatives apply

Answer: C

Explanation:BGP uses TCP as its transport protocol (port 179) to establish adjacency with neighbor. Itforms a TCPconnection with each of the configured neighbors and keeps track of the stateof these relationships byperiodically sending a BGP TCP keepalive message.In Exhibitline 21 provides information about the number of times the router has established a TCP

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connectionand dropped connections with neighbors. This is useful for identifying aflapping connection with a neighbor.


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Study the exhibits carefully. On the basis of the configuration that is provided, how wouldthe BGP updates that come from router Company1 be replicated inside autonomoussystem 65200?

A. All BGP updates that are received on router Company2 will be sent to routersCompany3 and Company4.Routers Company3 and Company4 will then forward those BGP updates to router R5.B. None of the BGP updates that are received on router Company2 will ever be receivedby router Company5.C. All BGP updates that are received on router Company2 will not be sent to routersCompany3 and Company4.D. All BGP updates that are received on router Company2 will be sent directly to routerCompany5.E. None of the other alternatives apply

Answer: B

Explanation:If the sending IBGP neighbor is not fully meshed with each IBGP router, the routers thatare not peering withthis router have different IP routing tables from the routers that arepeering with itIBGP configuration is based on full mesh topology with the exception of theuse of a route reflector. But in thisexhibit Companyg2 and Companyg5 are not configured

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as a BGP neighbor on IBGP. So Company2 and Companyg5don't exchange updates witheach other. Incoming routes from AS65100 to Company 2 will be sent toCompany3 andCompany4, but not to Company5.


Company2 Exhibit:

You work as a network engineer at Company.com. Study the exhibits carefully. What willCompany2 do with a packet sourced from within AS 64200 with a destination address of192.168.25.1?

A. It will be forwarded to the Company2 192.168.25.0 network.B. It will be dropped because network 192.168.25.0 is not in the Company1 routing table.C. It will be dropped because network 192.168.25.0 is not in the Company2 routing table.D. It will be forwarded to the null 0 interface of Company2 and dropped.E. None of the other alternatives apply

Answer: A

Explanation:In this example, Company2 will send the summary route of 192.168.24.0/22 to theCompany1 peer, which means all packets destined for any of the 4 internal AS64200networks will be forwarded to router Company2 from Company1.

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QUESTION: 116The Company network uses the autoconfiguration feature in their IPv6 network. Whichstatement best describes autoconfiguration for IPv6?

A. A router connected to the local link sends its 64 bit prefix address and the host appendsits MAC address to create its unique IPv6 address.B. A router connected to the local link sends a broadcast periodically to advertise thesubnet and the host appends its locally configured IPv4 address to create a unique IPv6address.C. A host will contact its local router to receive its unique IPv6 address.D. The local DHCP server will detect a new host has been added to the LAN segment andautomatically send a unique IPv6 address to the new host.E. None of the other alternatives apply.

Answer: A

Explanation:The first task in stateless autoconfiguration is for the host to create a unique interfaceidentifier to be used for any link-local, site-local, or global addresses. This interfaceidentifier, called EUI-64, is 64 bits that are adapted from the device’s layer two address,typically MAC-48 in LANs.

Reference:www.prolixium.com/files/ipv6_autocfg/ipv6_autocfg.ps

QUESTION: 117An IPv6 packet contains some differences to an IPv4 packet. Which three arecharacteristics of IPv6? (Select three)

A. An IPv6 header contains the next header field.B. An IPv6 header contains the protocol field.C. An IPv6 header contains the header checksum field.D. An IPv6 address is 128 bits long.E. An IPv6 header is 20 bits long.F. IPv6 routers send RA messages.

Answer: A, D, F

Explanation:

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All IPv6 addresses are 128 bits long to accommodate a far larger number of stations thanwhat was possible with the 32 bit IPv4 addresses. The following displays the IPv6 headerfield in detail: IPv6 header: Version. 4 bits.IPv6 version number.Traffic Class. 8bits.Internet traffic priority delivery value.Flow Label. 20 bits.Used for specifying specialrouter handling from source to destination(s) for a sequence of packets.Payload Length. 16bits unsigned.Specifies the length of the data in the packet. When cleared to zero, theoption is a hop-by-hop Jumbo payload.Next Header. 8 bits.Specifies the next encapsulatedprotocol. The values are compatible with those specified for the IPv4 protocolfield.HopLimit. 8 bits unsigned.For each router that forwards the packet, the hop limit isdecremented by 1. When the hop limit field reacheszero, the packet is discarded. Thisreplaces the TTL field in the IPv4 header that was originally intended to beused as a timebased hop limit.Source address. 16 bytes.The IPv6 address of the sending node.Destinationaddress. 16 bytes.The IPv6 address of the destination node.

Reference:http://www.networksorcery.com/enp/protocol/ipv6.htm

QUESTION: 118Hosts on the Company LAN are IPv6 enabled. When an IPv6 enabled host boots, it sendsa router solicitation (RS) message to the Company router. This IPv6 router responds with arouter advertisement (RA). Which two items are contained in the RA? (Select two)

A. Any route advertisements it has receivedB. Request for the local host IP addressC. Keepalive timersD. Prefixes for the linkE. Lifetime of the prefixF. IPv6 address for the host

Explanation:In IP Version 6, Router Advertisements have the following attributes:• Routers advertise periodically– Max. time between advertisements can be in the range from 4 and 1800 seconds– The advertisement has a lifetime (= 0 if not a default router)

Answer: D, E

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• Advertisement contains one or more prefixes– Prefixes have a lifetime• Preferred lifetime• Valid lifetime• Specifies if stateful or stateless autoconfiguration is to be used• Plays a key role in site renumbering

QUESTION: 119The Company network is in the process of migrating the IP address scheme to use IPv6.Which of the following address types are associated with IPv6? (Select three)

A. UnicastB. PrivateC. BroadcastD. PublicE. MulticastF. Anycast

Answer: A, E, F

Explanation:IP version 6 introduced the concept of anycasts. The three IP address types used for IPv6are: Unicast - An IPv6 unicast address is an identifier for a single interface, on a singlenode. A packet that issent to a unicast address is delivered to the interface identified bythat address. Anycast - An anycast address is an address that is assigned to a set ofinterfaces that typically belong todifferent nodes. A packet sent to an anycast address isdelivered to the closest interface-as defined bythe routing protocols in use-identified by theanycast address. Multicast - An IPv6 multicast address is an IPv6 address that has a prefixof FF00::/8 (11111111). AnIPv6 multicast address is an identifier for a set of interfacesthat typically belong to different nodes.

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide_chapter09186a0080110dd2.html#99899

QUESTION: 120You wish to represent some IPv6 networks in a shorter form. What number is a validrepresentation for the 200F:0000:AB00:0000:0000:0000:0000/56 IPv6 prefix?

A. 200F:0:0:AB/56

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B. 200F:0:AB00::/56C. 200F::AB00/56D. 200F:AB/56E. None of the other alternatives apply

Answer: B

Explanation:Due to the method of allocating certain styles of IPv6 addresses, it will be common foraddresses to containlong strings of zero bits. In order to make writing addresses containingzero bits easier a special syntax isavailable to compress the zeros. The use of "::" indicatesmultiple groups of 16-bits of zeros. The "::" can onlyappear once in an address. The "::"can also be used to compress the leading and/or trailing zeros in an address.For examplethe following addresses:1080:0:0:0:8:800:200C:417A a unicastaddressFF01:0:0:0:0:0:0:43 a multicast address0:0:0:0:0:0:0:1 the loopbackaddress0:0:0:0:0:0:0:0 the unspecified addressesmay be representedas:1080::8:800:200C:417A a unicast addressFF01::43 a multicast address::1 the loopbackaddress:: the unspecified addressesIn our example, the trailing zero's can be compressedinto ::, giving us 200F:0:AB00:: as the address.

QUESTION: 121What is the IPv6 address FF02:2 used for within the Company IP Version 6 network?

A. All hosts in a particular multicast groupB. All routers in an autonomous systemC. All routers in a local segmentD. All host in a local segmentE. None of the other alternatives apply

Answer: C

Explanation:To identify all nodes for the node-local and link-local scopes, the following multicastaddresses are defined: FF01::1 (node-local scope all-nodes address) FF02::1 (link-localscope all- nodes address)To identify all routers for the node-local, link-local, and site-localscopes, the following multicast addresses aredefined: FF01::2 (node-local scope all-routersaddress) FF02::2 (link-local scope all-routers address) FF05::2 (site-local scope all-routersaddress)

Reference:http ://technet2.microsoft.com/windowsserver/en/library/8c07faf2-35b3-4f2a-920fd61ad76581ad1033.mspx?mfr=true

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QUESTION: 122The Company network is migrating to IP version 6. Which two statements are correctregarding the IPv6 addressing structure? (Select two)

A. An IPv6 interface can have multiple anycast addresses assigned to it.B. All IPv6 interfaces have a link-local address.C. An IPv6 interface can have only one unicast, anycast, and multicast address.D. IPv6 interfaces can only have one local and one global address.

Answer: A, B

Explanation:Anycast Address: IPv6 also defines a new type of address called anycast. An anycastaddress identifies a list ofdevices or nodes; therefore, an anycast address identifiesmultiple interfaces. You can assign multiple anycastaddress on single interface.Link-localAddress: Scope is configured to single link and assigned to an interface. The address isunique onlyon this link, and it is not routable off the link.

QUESTION: 123What are two rules for compacting IPv6 addresses? (Choose two)

A. Every 16-bit segment segment that consists of all zeroes can be represented with asingle colon. B. The trailing zeroes in any 16-bit segment do not have to be written.C. The leading zeroes in any 16-bit segment do not have to be written.D. Any single, continuous string of one or more 16-bit segments that consists of all zeroescan be represented with a double colon.E. The maximum number of times a double colon can replace a 16-bit segment thatconsists of all zeroes is two.F. Two zeroes in the middle of any 16-bit segment do not have to be written.

Answer: C, D

Explanation:Here are some abbreviation methods used to make it easier to work with IPV6.1.Whenever one or more successive 16-bit groups in an IPv6 address consist of all 0s, thatportion of theaddress can be omitted and represented by two colons (::). The two-colonabbreviation can be used only once inan address, to eliminate ambiguity.2. When a 16-bitgroup in an IPv6 address begins with one or more 0s, the leading 0s can be omitted.Thisoption applies regardless of whether the double-colon abbreviation method is usedanywhere in the address.Example:IPV6 address:2001:0001:0000:0000:00A1:0CC0:01AB:397A, this address can write on this form aswell:2001:1:0:0:A1:CC0:1AB:397Aor2001:0001::00A1:0CC0:0174AB:397Aor2001:1::A1:CC0:1AB:397A

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QUESTION: 124In the context of IP version 6, what is router solicitation?

A. A request made by a node to join a specified multicast groupB. A request made by a node for its IP addressC. A request made by a node for the IP address of the DHCP serverD. A request made by a node for the IP address of the local routerE. None of the other alternatives apply

Answer: D

Explanation:IPv6 Router solicitation is a message type used by hosts to the all-routers multicastaddress. Hosts send this message to learn the addresses of routers on a given link, as wellas their various parameters, without waiting for a periodic RA message. If a host has noconfigured IPv6 address, it sends an RS using the unspecified address as the source. If ithas a configured address, it sources the RS from the configured address.

QUESTION: 125You need to explain the differences between an IPv4 header and an IPv6 headr. In thiscomparison, which three statements are true? (Choose three)

A. An IPv6 header is half the size of an IPv4 header.B. An IPv4 header includes a checksum. However, an IPv6 header does not include one.C. A router has to recompute the checksum of an IPv6 packet when decrementing theTTL.D. An IPv6 header is simpler and more efficient than an IPv4 header.E. The 128-bit IPv6 address makes the IPv6 header more complicated than an IPv4 header.F. An IPv6 header has twice as many octets as an IPv4 header.

Answer: B, D, F

Explanation:IPv6 has simpler header than IPv4, which Provides better routing efficiency; no broadcastsand thus no potential threat of broadcast storms; no requirement for processing checksums;simpler and more efficient extension header mechanisms; and flow labels for per-flowprocessing with no need to open the transport inner packet to identify the various trafficflows.

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QUESTION: 126From the following list, which statement is true about IPv6?

A. Only one IPv6 address can be assigned to each interface.B. IPv6 hosts use anycast addresses to assign IP addresses to interfaces.C. Each host can autoconfigure its address without the aid of a DHCP server.D. Only one IPv6 address is assigned per node.E. None of the other alternatives apply

Answer: C

Explanation:Stateless autoconfiguration is a plug-and-play feature that enables devices to automaticallyconnect to an IPv6 network without manual configuration and without any server likeDHCP server. DHCP and DHCPv6 are known as stateful protocols because they maintaintables within dedicated servers.

QUESTION: 127IPv6 has been implemented on the Company WAN. Which address type does the IPv6address FF05:0:0:0:0:0:0:2 specify?

A. Site local unicastB. MulticastC. Link localD. Aggregable global unicastE. UnspecifiedF. None of the other alternatives apply

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Answer: B

Explanation:All IPv6 multicast addresses start with the first 8 bits of the address set to 1. Thus allmulticast addresses start with the hexadecimal notation FF (1111 1111). The multicastrange is as follows: FF00::/8 FFFF::/8 The second octet, following to the first octet of FF,identifies both the scope and the lifetime of the multicast address. In this way, IPv6 hasmillions of group multicast addresses to use in current and emerging technologies.

Reference:CCNP Self-Study CCNP BSCI Exam Certification Guide p.112

QUESTION: 128Company has migrated to IPv6 in their network. Which three IPv6 notations represent thesame address? (Select three)

A. 2031::130F::9C0:876A:130BB. 2031:0000:130F:0000:0000:09C0:876A:130BC. 2031:0:130F:::9C0:876A:130BD. 2031::130F:0::9C0:876A:130BE. 2031:0:130F:0:0:09C0:876A:130B F. 2031:0:130F::9C0:876A:130B

Answer: B, E, F

Explanation:With IP version 6, octets containing all zero’s can be simply represented as :, whileconsecutive zero fields can be represented as ::. Answer choices C and E are simply theshorthand version of the fully written IPv6 address shown in choice A. For a fullexplanation of the IPv6 address representation, see the reference link below:

Reference:http://www.ietf.org/rfc/rfc1924.txt?number=1924

QUESTION: 129You need to design an addressing scheme for the Company IPv6 network. What is thedifference between the IPv6 addresses ::/0 and ::/128?

A. ::/0 is the unspecified address, and ::/128 is the multicast address.B. ::/0 is the unicast address, and ::/128 is the multicast address.

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C. ::/0 is the anycast address, and ::/128 is the multicast address.D. ::/0 is the default route, and ::/128 is the unspecified address.E. ::/0 is the unicast address, and ::/128 is the anycast address.F. ::/0 is the anycast address, and ::/128 is the default address.G. None of the other alternatives apply

Answer: D

Explanation:::/128 is the unspecified address (RFC4291).::/0 is the default unicast route address.

Reference:Special-Use IPv6 Addresses - draft-ietf-v6ops-rfc3330-for-ipv6-04.txthttp://tools.ietf.org/html/draft-ietf-v6ops-rfc3330-for-ipv6-04

QUESTION: 130Which command must be globally enabled on router Company1 to support IPv6?

A. ip routing ipv6B. ipv6 unicast-routingC. ipv6 routingD. ip classlessE. ipv6 cef

Answer: B

Explanation:To support the processing and forwarding of IP version 6 packets, the “ipv6 unicast-routing “command must be enabled in global configuration mode. The following is aconfiguration example: ipv6 unicast-routing interface ethernet0/0 description connection toenterprise ipv6 address 2002:C0A8:2101::1/128

QUESTION: 131You have been tasked with setting up OSPF on an existing Company router using IPv6.Which command enables OSPF for IPv6 on a router?

A. ipv6 router ospf process-id

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B. router ospf process-idC. router ospf ipv6 process-idD. ipv6 ospf process-id area-idE. None of the other alternatives apply

Answer: A

Explanation:To enable Open Shortest Path First (OSPF) for IPv6 router configuration mode, use theipv6 router ospf command in global configuration mode.ipv6 router ospf process-idSyntaxDescription processidInternal identification. It is locally assigned and can be a positiveinteger from1 to 65535. The number used here is the number assignedadministrativelywhen enabling the OSPF for IPv6 routing process.

Reference:http://www.cisco.com/en/US/products/ps6922/products_command_reference_chapter09186a00801d6615.html#wp2027608

QUESTION: 132The command “ipv6 ospf 1 area 0” was issued on router Company1. What is true aboutthis command?

A. It must be issued before the network command to enable the OSPF process for IPv6.B. It must be issued after the network command to enable the OSPF process for IPv6.C. It must be issued in router global configuration mode to enable the OSPF process forIPv6.D. It must be issued in interface configuration mode to enable the OSPF process for IPv6.E. None of the other alternatives apply

Answer: D

Explanation:Cisco IOS enables OSPFv3 using interface subcommands, instead of using the OSPFv2method (using the network command in router configuration mode). To enable OSPFv3process ID (PID) 1 and area 0 on a given interface, the basic command is simply ipv6 ospf1 area 0.Example of configuring OSPFv3:R(Config)#ipv6 unicast-routingR(Config)#int s0/0R(Config-if)#ipv6 address 2ffa::1/64R(Config-if)#ipv6 ospf 1 area 0R(Config-if)#ipv6 ospf priority <priority>R(Config-if)#ipv6 ospf cost <cost>

QUESTION: 133

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Company is in the process of migrating from IP version 4 to version 6. Which twostatements are true about using IPv4 and IPv6 simultaneously on a network segment?(Select two)

A. IPv6 provides for more host IP addresses but IPv4 provides for more networkaddresses.B. Host configuration options for IPv4 can be either statically assigned or assigned viaDHCP. Host configuration options for IPv6 can be statically assigned only.C. IPv4 and IPv6 addresses can be simultaneously assigned to a host but not to a routerinterface.D. IPv6 allows a host to create its own IPv6 address that will allow it to communicate toother devices on a network configured via DHCP. IPv4 does not provide a similarcapability for hosts.E. Hosts can be configured to receive both IPv4 and IPv6 addresses via DHCP.

Answer: D, E

Explanation:The original specification of the Dynamic Host Configuration Protocol (DHCP) was madewith only IPv4 in mind. That specification has been subsequently revised, up to the latestversion of DHCP. With the arrival ofIPv6, a new DHCP specification for IPv6 has beendesigned and published as DHCPv6.These protocols allow nodes to communicate via IPv4or IPv6 (respectively) to retrieve configuration settings for operation in a managedenvironment. While an IPv6 node may acquire address-related configuration settings viaIPv6 stateless address auto configuration, such a node may wish to use stateless DHCPv6[5] for other administratively configured options, such as DNS or NTP.

Reference:RFC 4477: Dynamic Host Configuration Protocol (DHCP): IPv4 and IPv6 Dual-StackIssueshttp://www.ietf.org/rfc/rfc4477.txt

QUESTION: 134The Company WAN is shown below:

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Based on the network above, if Company1 is configured for 6to4 tunneling, what will bethe prefix of its IPv6 network?

A. AC1F:6401::/32B. 1723:1100:1::/48C. FFFF:AC1F:6401::/16D. 2002:AC1F:6401::/48E. 3FFE:AC1F:6401::/32

Answer: D

QUESTION: 135A Company router is configured as shown below:

Given the partial configuration shown above, which statement regarding IPv6 is true?

A. The configuration is an example of a 6to4 tunnel.B. The configuration is an example of a 4to6 tunnel.C. The configuration is an example of an encrypted IPv6 VPN tunnel.D. The configuration is an example of a one to one IPv6 tunnel.E. None of the other alternatives apply.

Answer: A

Explanation:Network Diagram This document uses the network setup shown in the diagram below.This figure shows the topology of a typical 6to4 tunnel to the 6bone.

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Configuration: Your 6bone ISP has provided you with the IPv4 address its 6bone borderrouter: 192.168.33.1. Use the preceding address information to configure a 6to4 tunnel onyour identified dual-stack border router by entering the following commands:

Enterprise Router ipv6 unicast-routing interface Ethernet0 description connection to 6boneISP ip address 192.168.99.1 255.255.255.0 interface Tunnel2002 description 6to4 tunnelto 6bone ISP no ip address no ip redirects ipv6 address 2002:C0A8:6301::1/128 tunnel

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source ethernet0 tunnel mode ipv6ip 6to4 ipv6 route 2002::/16 Tunnel2002 ipv6 route ::/02002:C0A8:2101::1

Reference:http://www.cisco.com/en/US/tech/tk872/technologies_configuration_example09186a00801f3b4f.shtml

QUESTION: 136Company is migrating from IPv4 to IPv6. What happens when an IPv6 enabled routerrunning version 6 to 4 must send a packet to a remote destination and the next hop is theaddress of 2002::/16?

A. The IPv6 packet is encapsulated in an IPv4 packet using an IPv4 protocol type of 41.B. The IPv6 packet has its header removed and replaced with an IPv4 header.C. The IPv6 packet is dropped because that destination is unable to route IPv6 packets.D. The packet is tagged with an IPv6 header and the IPv6 prefix is included.E. None of the other alternatives apply

Answer: A

Explanation:When the requesting site's 6to4 router sees that it must send a packet to another site (thatis, there is a non local destination), and that the next hop destination prefix contains thespecial 6to4 Top Level Aggregation (TLA)value of 2002::/16, the IPv6 packet isencapsulated in an IPv4 packet using an IPv4 protocol type of 41, as defined in theTransition Mechanisms RFC . The source IPv4 address will be the one in the requestingsite's6to4 prefix (which is the IPv4 address of the outgoing interface to the Internet on the6to4 router, and contained in the source 6to4 prefix of the IPv6 packet), and the destinationIPv4 address will be the one in the next hop destination 6to4 prefix of the IPv6 packet.

Reference:http://www.cisco.com/web/about/ac123/ac147/ac174/ac197/about_cisco_ipj_archive_article09186a00800c830a.html

QUESTION: 137Company is implementing IPv6 within their network. Which two statements are trueconcerning IPv6? (Select two)

A. Like IPv4, IPv6 broadcasts are sent to all nodes on a LAN segment. B. Mobile IP is built into IPv6 by default.C. The leading zeros in an address format are mandatory.D. IPSec is mandatory and built into IPv6.

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Answer: B, D

Explanation:All IPv6 nodes can potentially implement mobility as needed because the standards forMobileIPv6 have been defined by the IETF. Mobile IP defines how the mobile device canmove around without breaking its connection or changing its IPv6 address. With IPv4,IPsec is optional and you need to ask the peer if it supports IPsec. With IPv6, IPsecsupport is mandatory. By mandating IPsec, we can assume that you can secure your IPcommunication whenever you talkto IPv6 devices.

QUESTION: 138Company plans to migrate their network from IPv4 to IPv6 in the near future. Which threetechniques can be used to transition from IPv4 to IPv6? (Select three)

A. Dual stackB. NATC. Flow labelD. Mobile IPE. 6to4 tunnelingF. AnycastG. MBGP

Answer: A, B, E

Explanation:The four key strategies for deploying IPv6 are as follows: Deploying IPv6 over IPv4tunnels: These tunnels encapsulate the IPv6 traffic within the IPv4 packets, and areprimarily for communication between isolated IPv6 sites or connection to remote IPv6networks over an IPv4 backbone. The techniques include using manually configuredtunnels, generic routing encapsulation (GRE) tunnels, semiautomatic tunnel mechanismssuch as tunnel broker services, and fully automatic tunnel mechanisms such as IPv4-compatible and 6to4. Deploying IPv6 over dedicated data links: This technique enablesisolated IPv6 domains to communicate by using the same Layer 2 infrastructure as forIPv4, but with IPv6 using separate FrameRelay or ATM PVCs, separate optical links, ordense Wave Division Multiplexing (dWDM). Deploying IPv6 over MPLS backbones:This technique allows isolated IPv6 domains to communicate with each other, but over anMPLS IPv4 backbone. Multiple techniques are available at different points in the network,but each requires little change to the backbone infrastructure or reconfiguration of the corerouters because forwarding is based on labels rather than the IP header itself. DeployingIPv6 using dual-stack backbones: This technique allows IPv4 and IPv6 applications tocoexist in a dual IP layer routing backbone. All routers in the network need to be upgradedto be dualstackwith IPv4 communication using the IPv4 protocol stack and IPv6communication using the IPv6stack.In addition to the strategies for deploying IPv6 within

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your IPv4 environment, you also need protocol translation mechanisms (for example, aNAT-PT device to connect IPv6-only web browsers to IPv4-only webservers) or dual-stack servers (for example, an e- mail server that handles IPv4-only and IPv6-only mailclients)to allow communication between applications using IPv4 and applications usingIPv6. These mechanisms become increasingly important as IPv6 deployment moves fromthe testing to the actual usage phase, and more relevant as application developers decidethat continuing to support IPv4 is not cost-effective.

Reference:http://www.cisco.com/en/US/tech/tk872/technologies_white_paper09186a00800c9907.shtml#1098273

QUESTION: 139The Company network will use 6to4 tunneling to migrate from IPv4 to IPv6. Whichstatement is true concerning 6to4 tunneling?

A. Hosts and routers inside a 6to4 site will need a special code.B. An edge router must use IPv6 address of 2002::/16 in its prefix.C. IPv4 traffic is encapsulated with an IPv6 header.D. The edge routers can use any locally configured IPv6 address.E. None of the other alternatives apply

Answer: B

Explanation:A 6to4 tunnel is an automatic IPv6 tunnel where a 6to4 border router in an isolated IPv6network creates atunnel to a 6to4 border router in another isolated IPv6 network over anIPv4 infrastructure. The tunnel destination is determined by the globally unique, 32-bitIPv4 address of the remote 6to4 border router that is concatenated to the prefix 2002::/16.6to4 tunnels are configured between 6to4 border routers or between 6to4border routers andhosts.A 6to4 relay service is a 6to4 border router that offers traffic forwarding to the IPv6Internet for remote 6to4border routers. A 6to4 relay forwards packets that have a 2002::/16source prefix.

Reference:IPv6: Providing IPv6 Services over an IPv4 Backbone UsingTunnelshttp://www.cisco.com/en/US/docs/ios/solutions_docs/ipv6/v6sertun.html

QUESTION: 140Router Company1 Exhibit:

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Router Company1 is configured as shown in the exhibit. Based on the information shown,which two statements are true about Company1’s configuration? (Select two)

A. This configuration is referred to as a stacker.B. This configuration is referred to as a dual stack.C. This configuration is referred to as a dual-stack 6to4 tunnel.D. This configuration is referred to as a stacker 6to4 tunnel.E. This configuration will attempt to route packets using IPv4 first, and if that fails, thenIPv6.F. The configuration allows applications on the same segment to communicate via IPv4 orIPv6.

Answer: B, F

Explanation:This Company router demonstrates an example of an IPv6 Dual Stack configuration. Dualstack (Figure 1 below) runs both IPv4 and IPv6 protocol stacks on a router in parallel,making it similar to the multiprotocol network environments of the past, which often ranInternetwork Packet Exchange (IPX), AppleTalk, IP, and other protocols concurrently.The technique of deploying IPv6 using dual- stack backbones allows IPv4 and IPv6applications to coexist in a dual IP layer routing backbone. The IPv4 communication usesthe IPv4 protocol stack, and the IPv6 communication uses the IPv6 stack.As a transitionstrategy, dual stack is ideal for campus networks with a mixture of IPv4 and IPv6applications. Figure 1: Dual-Stack Example

Reference:http://www.cisco.com/en/US/products/ps6553/products_white_paper0900aecd805c54d0.shtml

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The Company network is migrating to IPv6 and needs to maintain communication betweenthe IPv4 and IPv6 network segments. Based on the exhibit shown, which statement iscorrect regarding the operation of NAT-PT between the IPv4 and IPv6 networks shown?

A. ICMP can be used to determine the IPv6-toIPv4 address mapping.B. The router will determine the IPv4 destination address.C. The host is statically configured with the IPv6-to-IPv4 address mapping.D. The source IPv6 host can use DNS to determine the IPv6-to-IPv4 address mapping.E. None of the other alternatives apply.

Answer: D

Explanation:The following example shown below from the NAT-PT Internet draft explains thisbest:Example: DNS updates with dynamic V4 address assignments^| [DNS]-----[DNS]------[DNS]-------[DNS][IPv6-B]-+ | || | +==============+ |[IPv6-A]-+----[NAT-PT]------|IPv4 network |--[IPv4-C]|+==============+(pool of v4 addresses)Figure 2: IPv4 toIPv6 communicationHost IPv6-A has an IPv6 address -> FEDC:BA98::7654:3210HostIPv6-B has an IPv6 address -> FEDC:BA98::7654:3211Host IPv4-C has an IPv4 address -> 132.146.243.30NAT-PT has a pool of addresses including the IPv4 subnet120.130.26.0Say host C wants to communicate with Host A,Host C can not send a packetto an IPv6 address of Host Abecause Host C can not use an IPv6 address and Host A doesnot have an IPv4 address.Host A, however, has a DNS name, which has the same format inIPv4 and IPv6. Host C makes a name lookupthrough its local DNS server. The DNS serverdoes not have a record of IPv4 address attached to this name soit forwards the request to aparent server. The request at some point reaches the Primary DNS server of the IPv6stubdomain, which redirects the request to the NAT-PT. The NAT-PT returns a valid IPv4address (e.g: fromits pool of addresses) to the DNS server and eventually the reply returnsto Host C, while NAT-PT retainsthe address mapping for a fixed amount of time (until anactual session is initiated). The TTL values on allDNS resource records (RRs) returned byNAT-PT would be set to 0.Host C can now initiate a connection to Host A with an IPv4

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packet which includes the followingaddresses from figure 2: say SA=132.146.243.30 andDA=120.130.26.10.On receiving the packet, the NAT-PT, recognizes the session andtranslates the packets and its addresses asnormal to SA=PREFIX::132.146.243.30 andDA= FEDC:BA98::7654:3210.Note that in the above configuration we assume that theDNS server of the V6 domain is co-located with theNAT-PT, thus, the details of theDNS/NAT-PT interaction are an implementation issue.

Reference:Network Address Translation - Protocol Translation (NAT-PT) InternetDrafthttp://tools.ietf.org/html/draft-ietf-ngtrans-natpt-01

QUESTION: 142Companyg is using 6to4 tunneling within their IPv6 network. Which two statements aboutthis kind of tunneling are accurate? (Choose two)

A. 6to4 is a manual tunnel method.B. Prepending a reserved IPv6 code to the hexadecimal representation of 192.168.0.1facilitates 6to4 tunneling.C. Each 6to4 site receives a /48 prefix in a 6to4 tunnel.D. 2002::/48 is the address range specifically assigned to 6to4.E. Prepending 0x2002 with the IPv4 address creates an IPv6 address that is used in 6to4tunneling.

Answer: C, E

Explanation:The 6to4 transition mechanism provides a solution to the complexity problem of buildingmanually configuredtunnels to an ISP by advertising a site's IPv4 tunnel endpoint (to beused for a dynamic tunnel) in a specialexternal routing prefix for that site.The specificationof a 48- bit external routing prefix in the IPv6 Aggregatable Global Unicast AddressFormatthat provides just enough space to hold the 32 bits required for the 32-bit IPv4tunnel endpoint address (calledV4ADDR in Figure 3) makes this setup possible.Sendingand Receiving Rules for 6to4 RoutersWhen the requesting site's 6to4 router sees that itmust send a packet to another site (that is, there is a nonlocaldestination), and that the nexthop destination prefix contains the special 6to4 Top Level Aggregation (TLA)value of2002::/16, the IPv6 packet is encapsulated in an IPv4 packet using an IPv4 protocol type of41, asdefined in the Transition Mechanisms RFC.

Reference:Routing IPv6 overIPv4www.cisco.com/web/about/ac123/ac147/ac174/ac197/about_cisco_ipj_archive_article09186a00800c830a.html

QUESTION: 143

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Company is using 6to4 tunnels in their IPv6 network. Which two statements are true aboutthese tunnels? (Choose two)

A. In a 6to4 tunnel, the first two bytes of the IPv6 address will be 0x2002 and the next fourbytes will be the hexadecimal equivalent of the IPv4 address.B. In a 6to4 tunnel, the IPv4 address 192.168.99.1 would be converted to the2002:1315:4463:1::/64 IPv6 address.C. In a 6to4 tunnel, the IPv4 address 192.168.99.1 would be converted to the2002:c0a8:6301::/48 IPv6 address.D. In a 6to4 tunnel, the first two bytes of the IPv6 address will be locally derived and thenext two bytes will be the hexadecimal equivalent of the IPv4 address.E. In a 6to4 tunnel, the IPv4 address 192.168.99.1 would be converted to the2002:c0a8:6301::/16 IPv6 address.

Answer: A,C

Explanation:The 6to4 method uses the reserved prefix 2002::/16 concatenated with the hexadecimalequivalent of the IPv4 address to allow an IPv4 site to create and use a /48 IPv6 prefixbased on a single Globally routable reachable IPv4 address. For example, in a 6to4 tunnel,the first two bytes of the IPv6 address will be locally derived and the next two bytes willbe the hexadecimal equivalent of the IPv4 address.

Reference:BSCI study guide volume 2, Cisco Press, page 8-75.

QUESTION: 144You need to determine the best tunneling method to use within your IPv6 netwoek. Whichstatement best describes the difference between a manually configured IPv6 in IPv4 tunnelversus an automatic 6to4 tunnel?

A. An automatic 6to4 tunnel does not require dual-stack (IPv4 and IPv6) routers at thetunnel endpoints.B. An automatic 6to4 tunnel allows multiple IPv4 destinations.C. A manually configured IPv6 in IPv4 tunnel allows multiple IPv4 destinations.D. A manually configured IPv6 in IPv4 tunnel does not require dual-stack (IPv4 and IPv6)routers at the tunnel endpoints.E. None of the other alternatives apply.

Answer: B

Explanation:An automatic 6to4 tunnel allows isolated IPv6 domains to be connected over an IPv4network to remote IPv6networks. The key difference between automatic 6to4 tunnels and

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manually configured tunnels is that the tunnelis not point-to-point; it is point-to-multipoint.In automatic 6to4 tunnels, routers are not configured in pairsbecause they treat the IPv4infrastructure as a virtual nonbroadcast multiaccess (NBMA) link. The IPv4addressembedded in the IPv6 address is used to find the other end of the automatictunnel.The simplest deployment scenario for 6to4 tunnels is to interconnect multiple IPv6sites, each of which has atleast one connection to a shared IPv4 network. This IPv4network could be the global Internet or a corporatebackbone. The key requirement is thateach site has a globally unique IPv4 address; the Cisco IOS softwareuses this address toconstruct a globally unique 6to4/48 IPv6 prefix. As with other tunnelmechanisms,appropriate entries in a Domain Name System (DNS) that map betweenhostnames and IP addresses for bothIPv4 and IPv6 allow the applications to choose therequired address.

Reference:Implementing Tunneling forIPv6http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-tunnel.html

QUESTION: 145Which interface command on router Company1 would provide IPv4-Compatible IPv6tunnels within the Company network?

A. tunnel mode ipv6ip isatapB. tunnel mode ipv6ipC. tunnel mode ipv6ip auto-tunnelD. tunnel mode gre ipv6E. tunnel mode ipv6ip 6to4F. None of the other alternatives apply

Answer: E

Explanation:Example configuration of a tunnel interface: interface Tunnel2002 description 6to4 tunnelto 6bone ISP no ip address no ip redirects ipv6 address 2002:C0A8:6301::1/128 tunnelsource ethernet0 tunnel mode ipv6ip 6to4

Reference:IPv6: Connecting to the 6bone Using 6to4 Tunnelshttp://www.cisco.com/en/US/docs/ios/solutions_docs/ipv6/6b624tnl.html

QUESTION: 146The following output was seen on an existing Company router:

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Based on the information shown above, what IOS command produces this output?

A. show ipv6 ospf interfaceB. show ipv6 ospfC. show ip ospfD. show ip ospf interfaceE. None of the other alternatives apply

Answer: B

Explanation:Sample Output for the show ipv6 ospf CommandThe following is sample output from theshow ipv6 ospf command:Router# show ipv6 ospfRouting Process "ospfv3 1" with ID172.16.3.3It is an autonomous system boundary routerRedistributing External Routesfrom,staticSPF schedule delay 5 secs, Hold time between two SPFs 10 secsMinimum LSAinterval 5 secs. Minimum LSA arrival 1 secsLSA group pacing timer 240 secsInterfaceflood pacing timer 33 msecsRetransmission pacing timer 66 msecsNumber of externalLSA 1. Checksum Sum 0x218DNumber of areas in this router is 1. 1 normal 0 stub 0nssaArea 1Number of interfaces in this area is 2SPF algorithm executed 9 timesNumber ofLSA 15. Checksum Sum 0x67581Number of DCbitless LSA 0Number of indication LSA0Number of DoNotAge LSA 0Flood list length 0

Reference:http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-OSPF.html#wp1071056

QUESTION: 147

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Part of the output from a Company router is shown in the exhibit:\

On the basis of the output shown on this Company router, which two statements are true?(Select two)

A. The output was generated by the “show ip interface” command.B. OSPF Version 2 has been enabled to support IPv6C. This is the designated router (DR) on the FastEthernet 0/0 link.D. Interface FastEthernet 0/0 was configured with the ipv6 ospf 1 area 1 command.E. The router was configured with the commands:F. router ospf 1G. network 172.16.6.0 0.0.0.255 area 1H. The IP address of the backup designated router (BDR) is FE80:205:5FFF:FED3:5808

Answer: D, F

Explanation:OSPFv3 supports IPv6. The configuration of OSPFv3 is not a subcommand mode of therouter ospf command as it is in OSPFv2 configuration. For example, instead of using thenetwork area command to identify networks that are part of the OSPFv3 network, theinterfaces are directly configured to specify that IPv6 networks are part of the OSPFv3network. The following describes the steps to configure OSPF for IPv6:

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There are several commonly used OSPFv3 show commands, including the show ipv6 ospf[process- id] [areaid] interfacee [interface] command.

Incorrect Answer:A: This is the output from the “show ipv6 interface”B: OSPF version 3 supports IPv6, not version 2.C: This is the BDR, not the DRE: The configuration of OSPFv3 is not a subcommand mode of the router ospf commandas it is in OSPFv2.

QUESTION: 148The command “clear ipv6 ospf process” was issued on a Company router. What does thiscommand accomplish?

A. The route table is cleared. Then the OSPF neighbors are reformed.B. The OSPF adjacencies are cleared and initiated again.C. The OSPF database is repopulated and then the shortest path first (SPF) algorithm isperformed.D. The shortest path first (SPF) algorithm is performed on the LSA database.E. None of the other alternatives apply

Answer: C

Explanation:When the process keyword is used with the clear ipv6 ospf command, the OSPF databaseis cleared andrepopulated, and then the SPF algorithm is performed. When the force-spfkeyword is used with the clear ipv6ospf command, the OSPF database is not clearedbefore the SPF algorithm is performed.

Reference:http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-ospf_support_TSD_Island_of_Content_Chapter.html

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Exhibit:

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Study the exhibits carefully. Routers Company1 and Company2 are IPv6 BGP peers thathave been configured to support a neighbor relationship over an IPv4 internetwork. Whichthree neighbor IP addresses are valid choices to use in the highlighted section of theexhibit? (Choose three)

A. ::0A43:0002B. 0A43:0002::C. 10.67.0.2::D. 10.67.0.2:0:0:0:0:0:0E. ::10.67.0.2F. 0:0:0:0:0:0:10.67.0.2

Answer: A, E, F

Explanation:Many transition strategies have been developed for IPv4 networks to migrate to IPv6service and for IPv6networks to intercommunicate over IPv4 networks like dual stack,tunneling and IPv4 Compatible IPv6 address.To configure BGP peer:router bgp<as>neighbor <IPv4 address> or <IPv6 address> or <ipv4 compatible IPv6 address>Thesethree answer choices are all valid IPv6 representations of the 10.67.0.2 IP address.


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Company1 exhibit:

Company2 exhibit:

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You work as a network engineer at Company.com. You study the exhibit carefully. The6to4 overlay tunnel configuration has been applied on each router to join isolated IPv6networks over a IPv4 network. Which statements regarding the 6to4 overlay tunnel is true?

A. The least significant 32 bits in the address referenced by the ipv6 route 2002::/16Tunnel0 command will correspond to the IPv4 address assigned to the tunnel source.B. The least significant 32 bits in the address referenced by the ipv6 route 2002::/16Tunnel0 command will correspond to the interface E0/0 IPv4 address.C. This is actually a configuration example of an IPv4-compatible tunnel and not a 6to4tunnel.D. The configuration is invalid since the tunnel source command must be configured withan IPv6 address.E. This is actually a configuration example of an ISATAP overlay tunnel and not a 6to4tunnel.

Answer: A

Explanation:6to4 tunnels use IPv6 addresses that concatenate 2002::/16 with the 32-bit IPv4 address ofthe edge router,creating a 48-bit prefix. The tunnel interface on R1 has an IPv6 prefix of2002:4065:4001:1::/64, where4065:4001 is the hexadecimal equivalent of 64.101.64.1, theIPv4 address of its interface in the IPv4 network.The tunnel interface on R2 has an IPv6prefix of 2002:4065:4101:1::/64, where 4065:4101 is the hexadecimalequivalent of64.101.65.1, the IPv4 address of its interface in the IPv4 network.When Company1receives a packet with IPv6 destination address of 2002:4065:4101:1:: (from the leftIPv6network, for example) Company1 will:* Take the IPv6 destination address of thatpacket (2002:4065:4101:1::) and convert it into an IPv4 address. Inthis case, the IPv4address is 40.65.41.01 in hex, which is 64.101.65.1 in decimal format.* Company1encapsulates the IPv6 packet in an IPv4 packet with a destination address of 64.101.65.1;thepacket is routed normally through the IPv4 network to R2* Company2 receives theIPv4 packet, decapsulates and routes it normally to its final IPv6 destination.

QUESTION: 151The Company network is redistributing routing information from OSPF and EIGRP.Which three steps are most helpful in verifying proper route redistribution? (Select three)

A. On the routers not performing the route redistribution, use the show ip route commandto see if the redistributed routes show up.B. On the ASBR router performing the route redistribution, use the show ip protocolcommand to verify the redistribution configurationsC. On the ASBR router performing the route redistribution, use the show ip routecommand to verify that the proper routes from each routing protocol are there.D. On the routers not performing the route redistribution, use the show ip protocolscommand to verify the routing information sources.

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E. On the routers not performing the route redistribution, use the debug ip routingcommand to verify the routing updates from the ASBR.

Answer: A, B, C

Explanation:In order to verify proper route redistribution, use the "show ip route" command on allrouters within thenetwork, as well as the ABSR, to verify that the routes are properly beingadvertised to all routers. In addition, issuing the "show ip protocol" can be used on therouter performing the redistribution to verify that routes arebeing redistributed into eachother.

Incorrect Answer:D: Issuing this command on a non-redistribution router will not tell us where and how theroutes are originatingfrom. This command will only be useful on the redistributing routers.E: This command can not be used to verify the redistributed routes.

QUESTION: 152Your network is running BGP as well as EIGRP. You are considering redistributing yourBGP routes into your EIGRP. What factors must you consider before redistributing BGProutes to IGP?

A. IGPs are limited to 250 routesB. A full BGP routing table may contain 100,000+ routesC. Because of possible routing loops, Cisco router configuration does not allow BGProutes to be redistributed into an IGP.D. Because BGP routes are not advertised unless they are known by the IGP, Ciscoautomatically redistributes routes into BGP.E. None of the other alternatives apply.

Answer: B

Explanation:The size of the BGP routing table must be taken into consideration. It is generally notrecommended toredistribute BGP routes into your IGP due to the large number of routesthat can be obtained from BGP.

Incorrect Answer:A: There is no such limit.C: BGP routes can very well be distributed into an IGP.D: BGP routers are not redistributed automatically.

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QUESTION: 153When you’re running an Interior Gateway Protocol (like OSPF or EIGRP); why wouldyou want to redistribute these routes into BGP?

A. So BGP can propagate this information to other IGP neighbors.B. So BGP can propagate this information to other IBGP neighbors.C. So BGP can propagate this information to other EBGP neighbors.D. So BGP can propagate this information to other OSPF neighbors.E. None of the other alternatives apply.

Answer: C

Explanation:When BGP is used between autonomous systems (AS), the protocol is referred to asExternal BGP (EBGP). Inorder to advertise the IP subnets used within your network toother autonomous systems, these routes must beinjected into BGP.Note: Customernetworks usually employ an Interior Gateway Protocol (IGP) such as RIP or OSPF fortheexchange of routing information within their networks

Reference:Border GatewayProtocolhttp://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/bgp.htm

QUESTION: 154The Company WAN is displayed below:

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Based on the configuration shown above and the default behavior of the routing protocols,which network will be present in the routing table of Company4?

A. Only networks belonging to EIGRP 100 will be present in the routing table ofCompany4.B. Network B, which is redistributed using the redistribute statement under EIGRP 100.C. Network A, which is automatically redistributed between two different EIGRPautonomous systems.D. Network A, which is automatically redistributed between two different EIGRPautonomous systems and Network B which is redistributed using the redistributestatement.

Answer: A

Explanation:To support multiple routing protocols within the same internetwork efficiently, routinginformation must beshared among the different routing protocols. For example, routeslearned from a RIP process may need to beimported into an IGRP process. This process ofexchanging routing information between routing protocols iscalled route redistribution.Such redistribution can be one- way or two-way. One-way routes are where oneprotocolreceives the routes from another. Two-way routes are where both protocols receive routesfrom eachother. Routers that perform redistribution are called boundary routers becausethey border two or moreautonomous systems or routing domains. In this exhibit OSPF is

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redistributed into EIGRP but EIGRP is notredistributed into OSPF so Companyg4'srouting table only contains routes that belong to EIGRP 100.

QUESTION: 155A Company router is configured as shown below:

Based on the output shown above, which three statements accurately describe the result ofapplying the exhibited route map? (Select three)

A. The map redistributes into EIGRP all routes that match the pfx prefix list and the fivemetric values- 40000, 1000, 255, 1, and 1500.B. The map prohibits the redistribution of all type 2 external OSPF routes.C. The map permits the redistribution of all type 1 external OSPF routes.D. The map prohibits the redistribution of all type 2 external OSPF routes with tag 6 set.E. The map prohibits the redistribution of all external OSPF routes with tag 6 set.F. All routes that do no match clauses 10 and 20 of the route map are redistributed withtheir tags set to 8.

Answer: C, D, F

Explanation:The route-map command is used to configure policy routing, which is often a complicatedtask. A route map isdefined using the syntax shown in thefigure.Syntax:RouterA(Config)#route-map map-tag [permit | deny ] <SequenceNumber>RouterA(Config-map-router)#The map-tag is the name, or ID, of the route map.This map- tag can be set to something easily recognizablename. The route-map commandchanges the mode on the router to the route-map configuration mode, fromthere conditionscan be configured for the route map.In this example, the first route-map entry (10) willdeny all type 2 routes with a tag of 6 (both must be true).The second route map (20) willset the metrics for all routes matching the pfx prefix list. Choice A is incorrectbecause themetrics shown do not need to match. These metrics will be assigned to the routes thatmatch.The last route-map (30) will set all other routes that did not already match 10 or 20with a tag of 8.

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QUESTION: 156Study the exhibit below carefully:

Based on the network shown above, will redistributed RIP routes from OSPF Area 2 beallowed in Area 1?

A. RIP routes will be allowed in Area 1 only if they are first redistributed into EIGRP.B. Because Area 1 is an NSSA, redistributed RIP routes will not be allowed.C. Redistributed RIP routes will be allowed in Area 1 because they will be changed intotype 5 LSAs in Area 0 and passed on into Area 1.D. Redistributed RIP routes will be allowed in Area 1 because they will be changed intotype 7 LSAs in Area 0 and passed on into Area 1.E. Because NSSA will discard type 7 LSAs, redistributed RIP routes will not be allowed inArea 1.

Answer: B

Explanation:The following are several area types that are possible on OSPF: Standard area - A standardarea can accept link updates and route summaries. Backbone area (transit area) - Wheninterconnecting multiple areas, the backbone area is the centralentity to which all otherareas connect. The backbone area is always Area 0. All other areas mustconnect to thisarea to exchange route information. The OSPF backbone has all the properties of astandardOSPF area. Stub area - A stub area is an area that does not accept information about routesexternal to theautonomous system, the OSPF internetwork, such as routes from non-OSPFsources. If routers need toreach networks outside the autonomous system, they use adefault route. A default route is noted as0.0.0.0/0. Totally stubby area - A totally stubbyarea is an area that does not accept external autonomous system(AS) routes and summaryroutes from other areas internal to the autonomous system. Instead, if therouter needs tosend a packet to a network external to the area, it sends it using a 0.0.0.0/0 defaultroute.Totally stubby areas are a Cisco proprietary feature. Not-so-stubby area (NSSA) - An

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NSSA is an area that is similar to a stub area but allows for importingexternal routes asType 7 LSAs and translation of specific Type 7 LSA routes into Type 5 LSAs.

QUESTION: 157The Company multi-protocol network is shown below:

Configuration exhibit:

Refer to the exhibit and the partial configuration on router Company2. On routerCompany4 all RIP routes are redistributed into the OSPF domain. A second redistributionis configured on router Company2 using a route map. Based on the configuration on routerCompany2, which EIGRP external routes will be present in the routing table ofCompany1?

A. The routes originating from the RIP routing domainB. All OSPF inter and intra-area routesC. The routes originating from the OSPF stub areaD. All routes originating from RIP and OSPF routing domainsE. None of the other alternatives apply

Answer: A

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Explanation:The route-map command is used to configure policy routing, which is often a complicatedtask. A route map isdefined using the syntax shown in thefigure.Syntax:RouterA(Config)#route-map map-tag [permit | deny ] <SequenceNumber>RouterA(Config-map-router)#The map-tag is the name, or ID, of the route map.This map- tag can be set to something easily recognizablename. The route-map commandchanges the mode on the router to the route-map configuration mode, fromthere conditionscan be configured for the route map.Route maps operate similar to access lists, byexamining one line at a time and when a match is found, action istaken. Route maps aredifferent from numbered access lists because they can be modified without changingtheentire list. Each route map statement is given a number. If a sequence number is notspecified, the first routemap condition will automatically be numbered as ten (10). Thesecond condition will automatically benumbered as 20, and so on. The optional sequencenumber can be used to indicate the position that a new routemap is to have in the list ofroute maps already configured with the same name.In Exhibit Access-list is created todeny from 50.50.50.0 and 60.60.60.0 (OSPF Domain) and that is called byroute-mapCompanyg.While redistributing OSPF routes into EIGRP Companyg rout-map is called soit denies to publish the RIP domainnetwork into the EIGRP.

QUESTION: 158Router Company2 connects two different routing domains as shown below:

Company2 is configured as shown below:

During the redistribution process configured on Company2, some of the EIGRP routes,such as 10.1.1.0/24 and 10.2.2.0/24, are not being redistributed into the OSPF routingdomain. Which two items could be a solution to this problem? (Select two)

A. Change the EIGRP AS number from 100 to 1 in the redistribute command.B. Configure the redistribute command under router eigrp 1 instead.C. Change the metric-type to 2 in the redistribute command.D. Change the metric to an EIGRP compatible metric value (bandwidth, delay, reliability,load, MTUs) in the redistribute command.E. Add the subnets option to the redistribute command.

Answer: A, E

Explanation:

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In this example, the router is configured for EIGRP AS 1, but EIGRP AS 100 is beingredistributed into OSPFso the EIGRP AS needs to be changed from 100 to 1.The subnetskeyword tells OSPF to redistribute all subnet routes. Without the subnets keyword, onlynetworksthat are not subnetted are redistributed by OSPF .Example:Router A(config)#router ospf 109Router A(config- router)#redistribute rip subnetsRouter A(config-router)#network 130.10.62.0 0.0.0.255 area 0Router A(config-router)#network 130.10.63.0 0.0.0.255 area 0The subnets keyword tells OSPF to redistribute all subnet routes. Without the subnetskeyword, only networksthat are not subnetted are redistributed by OSPF .

QUESTION: 159The Company network administrator is troubleshooting a redistribution problem with RIProutes into OSPF . Given the exhibited configuration commands shown below, whichstatement is true?

A. Redistributed routes will maintain their original RIP routing metric.B. Redistributed routes will have a default metric of 0 and will be treated as unreachableand not advertised.C. Redistributed routes will be tagged as external type 2 (E2) with a metric of 20.D. Redistributed routes will be tagged as external type 1 (E1) with a metric of 30.E. Redistributed routes will have a default metric of 0 but will not be treated as reachableand will be advertised.F. None of the other alternatives apply

Answer: C

Explanation:If a metric is not specified, OSPF puts a default value of 20 when redistributing routesfrom all protocols exceptBorder Gateway Protocol (BGP) routes, which get a metric of 1.The default metric type for OSPF is external,type 2.

Reference:http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009487e.shtml#ospf

QUESTION: 160

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The Company network administrator is troubleshooting a redistribution of OSPF routesinto EIGRP. Given the exhibited commands shown below, which statement is true?

A. Redistributed routes will have an external type of 2 and a metric of 20.B. Redistributed routes will have a default metric of 0 but will be treated as unreachableand not advertised.C. Redistributed routes will maintain their original OSPF routing metric.D. Redistributed routes will have a default metric of 0 and will be treated as reachable andadvertised.E. Redistributed routes will have an external type of 1 and a metric of 1.F. None of the other alternatives apply.

Answer: B

Explanation:IGRP and EIGRP IGRP and EIGRP are Cisco proprietary routing protocols. Both use acomposite metricmade up of the following:?? Bandwidth?? Delay?? Reliability??LoadEIGRP requires you to specify a metric except when the redistribution occurs withanother instance of EIGRPor IGRP. All instances of EIGRP and IGRP use the samecomposite style of metrics, meaning that the metricwill carry across the redistribution.Redistributing any other routing protocol, except EIGRP or IGRP, intoEIGRP will requireyou to set the metric.Although the redistribute ospf 5 command is configured underEIGRP, there is no configuration of the defaultmetriccommand. When redistributingbetween different routing protocols, the default-metric command must beconfigured.When one routing protocol is being redistributed into another, the router doesn't have away totranslate the routing metric from one routing protocol into another. If a metric is notspecified, the metric valuedefaults to 0. Because EIGRP uses a composite metric, it willnot understand a metric of 0 and the routes willnot be used. The default-metric commandis used so that the network administrator can manually initialize therouting metric duringroute redistribution. The fix for this problem: Configure a default metric under EIGRPinthis router

QUESTION: 161You need to implement route redistribution on a number of the Company OSPF routers.Which three statements are true when configuring redistribution for OSPF? (Select three)

A. Subnets redistribute by default.B. The default metric is 20.

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C. The default metric is 10.D. The default metric type is 1.E. Subnets do not redistribute by default.F. The default metric type is 2.

Answer: B, E, F

Explanation:If a metric is not specified, OSPF puts a default value of 20 when redistributing routesfrom all protocols exceptBorder Gateway Protocol (BGP) routes, which get a metric of1.For all redistributed OSPF routes, the default metric type is 2.When there is a major netthat is subnetted, you need to use the keyword subnet to redistribute protocols intoOSPF .Without this keyword, OSPF only redistributes major nets that are not subnetted.

Reference:http//www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009487e.shtml#ospf

QUESTION: 162A Company OSPF router has been configured in the following manner:router ospf 1 redistribute eigrp 1 metric 33 subnetsBased on this information, what function does the 33 parameter in the redistributecommand serve?

A. It specifies the metric cost to be applied to the redistributed routes.B. It specifies the administrative distance on the redistributed routes.C. It specifies the metric limit to 33 subnets in each OSPF route advertisement.D. It specifies the process-id for the pseudo process that injects the EIGRP routes intoOSPF .

Answer: A

Explanation:It specifies the metric cost to be applied to the redistributed routes. In this example, ametric of33 will be applied to all of the EIGRP routes when redistributed into OSPF . The"subnets" keyword specifiesthat subnet mask information is to be preserved during thisprocess.

Reference:Redistributing RoutingProtocolshttp://www.cisco.com/warp/public/105/redist.html#examples

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QUESTION: 163You are configuring redistribution to advertise EIGRP routes into OSPF on a boundaryrouter. Given the configuration:router ospf 1redistribute eigrp 1 metric 25 subnets Whichis the function of the “subnets” keyword in the redistribute command?

A. It specifies subnetted routes should be advertised into OSPF .B. It specifies subnetted routes should be advertised out of OSPF .C. It specified routes that will be summarized on the 25-bit boundary.D. It specifies a limit of 25 subnets for each OSPF route advertisement.E. None of the other alternatives apply.

Answer: A

Explanation:The subnets keyword is used to specify that subnet mask information used by classlessrouting protocols shouldbe preserved when redistributed into the other routing protocol. Inthis case, the EIGRP routes, includingsubnet masks, will be redistributed into OSPF.

Incorrect Answer:B: Here the routes are being placed into the OSPF routing process, not advertised out of.C, D: In this configuration, the value of "25" means that the metric will be 25 when placedinto OSPF . It hasnothing to do with the bit boundary or the number of subnets that can beadvertised.

QUESTION: 164The Company network is in the process of changing the routing protocol from EIGRP toOSPF, as well as changing the IP network to the private 10.0.0.0/8 network. To do this,router Company1 has been configured as shown below: router ospf 100 redistribute eigrp100 metric 100 metric-type 1 network 172.16.0 0.0.0.255.255 All other configurations usethe default values. You want to successfully redistribute all networks and subnets on theCompany network. What can you do to accomplish this goal? (Choose two)

A. Change the OSPF process-id number from 100 to 1 in the router ospf command.B. Configure the redistribute command under router eigrp 1 instead.C. Change the EIGRP AS number from 100 to 1 in the redistribute command.D. Add the subnets option to the redistribute command.E. Add the network 10.0.0.0 0.255.255.255 command under router ospf 100.F. Change the metric to an EIGRP compatible metric value for Bandwidth, Delay,Reliability, Load, MTU, (such as 64 1000 100 1 1500) in the redistribute command.

Answer: D, E

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Explanation:The use of the "subnets" keyword will ensure that the subnet mask information will beredistributed into theOSPF process. Since both EIGRP and OSPF support the use ofVLSM, this is recommended.Since the network is being migrated to OSPF, it would bebest to begin advertising the network via the OSPFprocess, as shown in answer choice E.

QUESTION: 165A policy needs to be implemented on Router Company2 so that any traffic sourced from172.16.10.0/24 will be forwarded to Router Company3. Which configuration on RouterCompany2 will achieve the desired effect? Exhibit:

A.access-list 1 permit 172.16.10.0 0.0.0.255!interface e0ip policy route-map policy!route-map policy permit 10match ip address 1set ip next-hop 172.16.14.4B.access-list 1 permit 172.16.10.0 0.0.0.255!interface s0ip policy route-map policy!route-map policy permit 10match ip address 1

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set ip next-hop 172.16.12.3C.access-list 1 permit 172.16.10.0 0.0.0.255!interface e0ip policy route-map policy!route-map policy permit 10match ip address 1set ip next-hop 172.16.12.2D.access-list 1 deny 172.16.10.0 0.0.0.255!interface s0ip policy route-map policy!route-map policy permit 10match ip address 1set ip next-hop 172.16.12.2

Answer: B

Explanation:Route-map allows conditions to be tested against a packet or route using the matchcommands. If the conditionsmatch, actions are taken to modify attributes of the packet orroute. These actions are specified by the setcommands.To accomplish the condition asdefined on questions, first define the access-list by permitting the172.16.10.0/24. Thencreate a route-map by matching condition of access-list and set next-hop torouterCompany3.

QUESTION: 166The Company routed network is shown below:

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The relevant portion of the configuration of router Company2 is shown below:

You work as a network technician at Company.com. Study the exhibits carefully. BothCompany5 and Company2 are performing two-way IGRP/RIP route redistribution.Whatbehavior will Company2 use with the given Company2 configurations?

A. Updates about 192.168.1.0 that are learned through RIP will be ignored.B. Updates about 192.168.1.0 will be advertised out the s0 interface.C. Updates about 192.168.1.0 that are heard through the s1 interface will be ignored.D. Updates about 192.168.1.0 that are learned through IGRP will be added to the routingtable, but not advertised to Company1.

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Answer: C

Explanation:When a distribute list is defined, the access list that it is tied to is used to define the routingupdates that arepermitted. In our example, the access list specifies that only the192.168.1.0 network is to be filtered, while allother network advertisements are allowed.Since the distribute list specifies that this filter is to be used forincoming updates oninterface serial 1, choice C is correct.

QUESTION: 167The Company WAN is depicted below:

Company3 is redistributing the EIGRP routes into OSPF . What will the EIGRP routesappear in the routing table of Company1?

A. OB. O IAC. O E2D. DE. D EX

Answer: C

Explanation:O E1 or O E2. The routes in this LSA are external to the autonomous system. They can beconfigured to have one of two values. E1 will include the internal cost to the ASBR addedto the external cost reported by the ASBR. E2 does not compute the internal cost – it justreports the external cost to the remote destination.

QUESTION: 168

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During a redistribution of routes from OSPF into EIGRP, the Company administratornotices that none of the OSPF routes are showing up in EIGRP. What are two possiblecauses? (Choose two.)

A. Incorrect distribute lists have been configuredB. Missing ip classless commandC. CEF not enabledD. No default metric configured for EIGRP

Answer: A, D

Explanation:Possible reasons for OSPF routes not showing up include the use of distribute lists tocontrol routing and no metric is configured either with the redistribute command or withdefault-metric. Remember while redistributing into RIP or EIGRP, you should provide themetric. Here are the default seed metrics for various protocols: RIP : Infinity EIGRP :Infinity OSPF : 20 IS-IS: 0

QUESTION: 169The Company administrator is redistributing OSPF into RIP. RIP is routing the128.103.36.0/24 network. OSPF is routing the 128.103.35.32/28 network. Users in the RIPdomain cannot reach devices in the OSPF domain. Which two tasks must be done toenable RIP to advertise the routes learned from OSPF into the RIP domain? (Choose two.)Exhibit:

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A. Redistribute configured static routes into RIP.B. Tune the OSPF default metrics to allow seamless redistribution into RIP.C. Add a static route that points to the OSPF domain address space with a /24 networkmask with a next hop of null0.D. Add a static route that points to the RIP domain address space with a /24 network maskand a next hop of 128.103.36.2.E. Use a route map statement inserted into a distribute list to control routing updates.

Answer: A, C

Explanation:By configuring a statis route to null 0, and then redistributing this statis route into RIP, willallow the RIP users to learn about the summarized route into the OSPF network. Trafficwill not be dropped into the null 0 bucket because Company2 has more specific routes, sothis router will forwad the packets accordingly.

QUESTION: 170The Company WAN is shown in the following diagram:

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Exhibit, Router Configuration

Which command should be added to CompanyB under router bgp 100 to allow only theexternal OSPF routes to be redistributed to CompanyC?

A. redistribute ospf 1B. redistribute ospf 1 match external 1C. redistribute ospf 1 match external 2D. redistribute ospf 1 match external 1 external 2

Answer: D

Explanation:Redistribution of Only OSPF External (Type 1 and 2) Routes into BGPUse the externalkeyword along with the redistribute command under router bgp to redistributeOSPFexternal routes into BGP. With the external keyword, you have three choices:redistribute both external type-1 and type-2 (Default) redistribute type-1 redistribute type-2Enter the commands in the configuration mode as described here:RTB(config-router)#router bgp 100RTB(config-router)# redistribute ospf 1 match external 1 external 2

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QUESTION: 171Company is implemting IPv6 into their existing IPv4 netwrok. Which statement is trueabout incorporating IPv6 into an already existing IPv4 network?

A. Only OSPF version 3 can be utilized for routing IPv4 and IPv6.B. IPv4 and IPv6 networks can be routed simultaneously.C. IPv6 can be routed using the same routing protocol versions as IPv4D. A router routing for IPv6 and IPv4 must convert IPv4 packets to IPv6 packets to routethem.E. None of the other alternatives apply

Answer: B

Explanation:The transition from IPv4 to IPv6 does not require an upgrade on all nodes at the sametime. Many transitionmechanisms like dual stack, tunneling etc enable smooth integrationof IPv4 to IPv6.You can configure IPv4 as well as IPv6 Address on same router's sameinterface, so you can route IPv4 routeand IPv6 route simultaneously.Here is the example toconfigure IPv4 and IPv6 address on the same interface:Router(Config)#ints0/0Router(Config-if)#ip address 1.1.1.1 255.255.255.0Router(Config-if)#ipv6 addressaffe::1/64

QUESTION: 172In this Company IPv6 network, an IPv6 overlay tunnel is required to communicate withisolated IPv6 networks across the existing IPv4 infrastructure. There are currently fiveIPv6 overlay tunnel types. Which three IPv6 overlay tunnel statements are true? (Choosethree)

A. Overlay tunnels can only be configured between border routers capable of supportingIPv4 and IPv6.B. An manual overlay tunnel supports point-to-multipoint tunnels capable of carrying IPv6and Connectionless Network Service (CLNS) packets.C. Overlay tunneling encapsulates IPv6 packets in IPv4 packets for delivery across anIPv4 infrastructure.D. Overlay tunnels can be configured between border routers or between a border routerand a host capable of supporting IPv4 and IPv6.E. Cisco IOS supports manual, generic routing encapsulation (GRE), IPv4-compatible,6to4, and Intra- Site Automatic Tunnel Addressing Protocol (ISATAP) overlay tunnelingmechanisms.F. Cisco IOS supports manual, generic routing encapsulation (GRE), IPv6-compatible,4to6, and Multiprotocol Label Switching (MPLS) overlay tunneling mechanisms.

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Answer: C, D, E

Explanation:Overlay tunneling encapsulates IPv6 packets in IPv4 packets for delivery across an IPv4infrastructure. This issimilar to how you create a generic routing encapsulation (GRE)tunnel to transport Internetwork PacketExchange (IPX) traffic through an IP network. Atthe tunnel head end, an IPv6 packet is encapsulated into IPv4packet and sent to the remotetunnel destination. This is where the IPv4 packet header is stripped, and theoriginal IPv6packet is forwarded further into an IPv6 cloud. This can be done between border routersorbetween a border router and a host capable of supporting IPv4 and IPv6These are thefive methods of tunneling IPv6 traffic: Manual IPv6 tunnels Automatic IPv4-Compatibletunnels GRE Automatic 6to4 tunnels Intra-Site Automatic Tunnel Addressing Protocol(ISATAP) Tunnels

Reference:Tunneling IPv6 through an IPv4Networkhttp://www.cisco.com/en/US/tech/tk872/technologies_configuration_example09186a00800b49a5.shtml

QUESTION: 173The Company network is displayed below:

Router Company2 was configured as shown below:

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Based on the exhibits above, which statement is true.

A. All routes matching access list 110 will be forwarded.B. There is a set entry missing in the route-map REDIST-MAP deny 20 statement.C. The set metric-type entry is not a valid route-map command.D. There is a match entry missing in the route-map REDIST-MAP permit 30 statement.E. All routes not matching access list 101 or 110 will be flagged as an OSPF external type2 with a metric of 5000.F. None of the other alternatives apply.

Answer: E

Explanation:The route-map command is used to configure policy routing, which is often a complicatedtask. A route map isdefined using the syntax shown in thefigure.Syntax:RouterA(Config)#route-map map-tag [permit | deny ] <SequenceNumber>RouterA(Config-map-router)#The map-tag is the name, or ID, of the route map.This map- tag can be set to something easily recognizablename. The route-map commandchanges the mode on the router to the route-map configuration mode, fromthere conditionscan be configured for the route map.Route maps operate similar to access lists, byexamining one line at a time and when a match is found, action istaken. Route maps aredifferent from numbered access lists because they can be modified without changingtheentire list. Each route map statement is given a number. If a sequence number is notspecified, the first routemap condition will automatically be numbered as ten (10). Thesecond condition will automatically benumbered as 20, and so on. The optional sequencenumber can be used to indicate the position that a new routemap is to have in the list ofroute maps already configured with the same name.After entering the route-mapcommand, enter set and match commands in the route-map configuration mode.Each

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route-map command has a list of match and set commands associated with it. The matchcommandsspecify the match criteria. They are the conditions that should be tested todetermine whether to take action.The set commands specify the set actions. They are theactions to be performed if the match criteria are met.

QUESTION: 174The Company network administrator has configured more than one routing protocol withinthe network domain. What two situations could require the use of multiple routingprotocols in any network? (Select two)

A. When there are multiple paths to destination networks.B. When using UNIX host-based routers.C. When all equipment is manufactured by CiscoD. When smaller broadcast domains are desired.E. Because having multiple routing protocols confuses hackersF. When migrating from an older Interior Gateway Protocol (IGP) to a new IGP

Answer: B, F

Explanation:Simple routing protocols work well for simple networks, but networks grow and becomemore complex. Whilerunning a single routing protocol throughout your entire IPinternetwork is desirable, multiprotocol routing iscommon for a number of reasons,including company mergers, multiple departments managed by multiplenetworkadministrators, multivendor environments, or simply because the original routing protocolis no longerthe best choice. Often, the multiple protocols are redistributed into each otherduring a migration period fromone protocol to the other.

QUESTION: 175It isn’t always in your best interests to redistribute dynamically learned routes from aninterior gateway protocol to a border gateway protocol. Which of the following arepotential issues that can occur when doing so? (Select two)

A. Routing loops can occur.B. The routes are automatically summarized.C. External IGP learned routes might not necessarily have originated in this AS.D. The BGP process will ignore the external IGP learned routes.

Answer: A, C

Explanation:It is fairly common to redistribute IGP routes (such as Enhanced IGRP, IGRP, IS-IS,OSPF, and RIP routes)into BGP. However, precautions should be made when doing so.

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Some of your IGP routes might have been learned from BGP (C), so you need to useaccess lists to prevent the redistribution of routes back into BGP, or else routing loops canoccur (A). In addition, when these IGRP routes are redistributed, all of the networks in theIGP routing table will be redistributed, including those that were learned externally.

Incorrect Answer:B: With redistribution into exterior protocols such as BGP, no routes are automaticallysummarized.D: All routes will be included in the redistribution, including externally learned routes.

Reference:Building Scalable Cisco Networks (Cisco Press) page 408.Using the Border GatewayProtocol for Interdomain Routinghttp://www.cisco.com/univercd/cc/td/doc/cisintwk/ics/icsbgp4.htm

QUESTION: 176What’s the preferred method of route redistribution, when two routes of different protocolsget exchanged? (Select two)

A. Use one way route redistribution when there is one path.B. Use one way route distribution when there are multiple paths.C. Use static routes when there are multiple paths.D. Use two way route distribution when there is one path.E. Use two way route redistribution where there are multiple paths.F. Use static routes when there is one path.

Answer: B, C

Explanation:B. One way redistribution- To avoid routing loops and problems with varying convergencetimes, allow routes to be exchanged in only one direction, not both directions. In the otherdirection, you should consider a default route.C. When you want to prevent routing loops - Many companies have large enoughnetworks that redundant paths are prominent. In some cases, for example, when a path tothe same destination is learned from two different routing protocols, you may want to filterthe propagation of one of the paths.


QUESTION: 177

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Router Company1 has been configured to filter routes. Which of the following are reasonsto control routing updates via route filtering? (Choose three)

A. To hide certain networks from the rest of the organization.B. For easier implementation.C. To control network overhead on the wire.D. For simple security.E. To prevent adjacencies from forming.

Answer: A, C, D

Explanation:Route filtering is used to filter out routing updates from other parts of the network, makingcertain networks unreachable from other parts of the organization. This can be done tosimply decrease the amount of traffic overhead associated with routing updates over partsof the network, or for security reasons.

Incorrect Answer:B: Route filtering requires a more complex router configuration, and can also lead todifficult troubleshooting.E: Route filtering will only block certain routes from incoming or outgoing, but the routingprotocol adjacencies will still be formed between neighboring routers.

QUESTION: 178Router Company4 is configured to filter some routes when advertising to its neighbors.Which statement about route filtering is true when it is used to control routing updates?

A. Only inbound routes can be filtered.B. Only outbound routes can be filtered.C. Routes to be filtered are selected by using distribute lists.D. Routes to be filtered are selected using only extended access lists.E. Routes to be filtered are selected by using the distribute-group command.

Answer: C

Explanation:The syntax for the distribute-list in/out command is:distribute-list access-list-numberin/out [interface-name]where access-list-number is the standard IP access-list againstwhich the contents of the incoming or outgoing routing update are matched. The[interface-name] argument is optional and specifies the interface on which the update isexpected. It is important to note that the access-list referred to in access-list-number isapplied to the contents of the update, not to the source or destination of therouting updatepackets. The router decides whether or not to include the contents in its routing table based

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on the access-lists. Forexample: access-list 1 permit 1.0.0.0 0.255.255.255routerripdistribute-list 1 in!--- The distribute-list command is given!--- under the routerconfiguration mode.

Incorrect Answer:A, B: Distribute lists can be used to filter traffic based on incoming as well as outgoingroutes.D: Standard access-lists are used with distribute lists, not extended access lists.E: This isan invalid command. The correct syntax is "distribute-list"

QUESTION: 179You are a network analyst at Company and are currently in the process of analyzing twoautonomous systems, each running a different routing protocol, but connected betweeneach other with redundant paths. The junior administrator wants to prevent routing loopsbetween the two autonomous systems and asks you if there’s an IOS feature that couldhelp him. How would you answer?

A. Route filtering.B. Passive interfaces.C. Static redistribution.D. Two-way redistribution.

Answer: A

Explanation:Multiple autonomous systems or routing domains can share route information through theredistributionprocess. Proper implementation of redistribution requires route filters toprevent feedback loops from forming.It is strongly recommended that redistributionbetween multiple ASs and multiple routing protocols beaccompanied by route filters.

Reference:CCNP #640-503 Building Scalable Cisco Networks (Cisco Press), More EIGRPScalability Rules

QUESTION: 180Two Company RIP routers are connected together as shown in the exhibit:

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Study the exhibit carefully. Which configuration command sequence would prevent thepropagation of updates for network 192.168.236.0/24 to the Company2 router?

A. Company2(config)# router ripCompany2(config-router)# passive-interface s0/0B. Company2(config)# access-list 1 deny 192.168.236.0Company2(config)# access-list 1 permit anyCompany2(config)# router ripCompany2(config-router)# distribute-list 1 out serial 0/0C. Company2(config)# access-list 1 deny 192.168.236.0Company2(config)# access-list 1 permit anyCompany2(config)# interface serial 0/0Company2(config-if)# ip access-group 1 inD. Company1(config)# router ripCompany1(config-router)# passive-interface s0/0E. Company1(config)# access-list 1 deny 192.168.236.0Company1(config)# access-list 1 permit anyCompany1(config)# interface serial 0/0Company1(config-if)# ip access-group 1 outF. Company1(config)# access-list 1 deny 192.168.236.0Company1(config)# access-list 1 permit anyCompany1(config)# router ripCompany1(config-router)# distribute-list 1 out serial 0/0G. None of the answers are correct.

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Answer: F

Explanation:Use the distribute-list command to pick and choose which routing updates a router willsend or receive. Byreferencing an access list, the distribute-list creates a route filter. This isa set of rules that precisely controlswhat routes a router will send or receive in a routingupdate. This command is available for all IP routingprotocols and can be applied to eitherinbound or outbound routing updates. When applied to inbound updates,the syntax forconfiguring a route filter is as follows:Router(config-router)#distribute-list access-list-number in [interface-name]When applied to outbound updates, the syntax can be morecomplicated as shown in the following:Router(config- router)#distribute-list access-list-number out [interface-name | routing-process | as-number]

QUESTION: 181Study the exhibit below carefully. What is the correct configuration to enable routerCompany4 to exchange RIP routing updates with router Company1 but not with routerCompany3?

A. Company4(config)# router ripCompany4(config-router)# neighbor 192.168.10.3Company4(config-router)# passive-interface fa0/0B. Company4(config)# interface fa0/0Company4(config-if)# neighbor 192.168.10.3Company4(config-if)# passive-interface fa0/0C. Company4(config)# router ripCompany4(config-router)# neighbor 192.168.10.34 no broadcastCompany4(config-router)# passive-interface fa0/0D. Company4(config)# interface fa0/0Company4(config-if)# neighbor 192.168.10.3

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Company4(config-if)# passive-interface 192.168.10.34

Answer: A

Explanation:Configure LAN interfaces as passive interfaces when enabling a routing protocol. Apassive interface receivesupdates, but does not send them. The passive-interface commandcan be used with all IP interior gatewayprotocols. It can be used with RIP, IGRP, EIGRP,OSPF, and IS-IS. The syntax of the command is as follows:Router(config-router)#passive-interface type numberNote: The passive-interface command works differently with thedifferent IP routing protocols that support it.In OSPF, the network address of the passiveinterface appears as a stub network. OSPF routing information isneither sent nor receivedby way of a passive interface. In EIGRP and OSPF, the router stops sending Hellopacketson passive interfaces. When this happens, the router cannot form neighbor adjacencies.Therefore, therouter cannot send and receive routing updates on the interface. It will beseen later in this module that thepassive effect can be achieved for an EIGRP interface byusing the distribute-list command. This can be donewithout preventing adjacencyrelationships.

QUESTION: 182The Company WAN is shown below


What are the effects of this RIP configuration on router Company1? (Select two)

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A. User traffic from the 172.16.1.0 network is denied by access-list 44B. No routing updates will be sent from router Company1 on interface BRI0 to routerCompany3C. The routing table on router Company1 will be updated with the route to routerCompany4D. The route to network 172.16.1.0 will not be entered into the routing table on routerCompany1E. Router Company1 will not advertise the 10.0.0.0 network to router Company3

Answer: C, D

Explanation:Answer C is correct because the Company4 networks are not being blocked. Answer D iscorrect as thedistribute list calls ACL 44 which denies network 172.16.1.0.

Incorrect Answer:A: This is incorrect because this ACL is being called by a distribute-list which only affectsroute table updates,not user traffic.B, E: Only incoming routes are filtered, not outgoing routes. All known routing entrieswill be advertised fromrouter Company1

QUESTION: 183Two Company routers are connected as shown below:

Router Company1 is configured as follows:

Based on the information shown above, what is the effect of the “distribute-list” commandin the Company1 configuration?

A. Company1 will filter only the 172.24.1.0/24 route from the Company2 RIP updates.B. Company1 will permit only the 10.0.0.0/24 route in the Company2 RIP updates.

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C. Company1 will filter 10.1.0.0/24 and the 172.24.1.0/24 routes from the Company2 RIPupdates.D. Company1 will not filter any routes because there is no exact prefix match.

Answer: C

Explanation:The distribute list is used to define the routing updates to be permitted through theinterface. In the exampleabove, the filter list specifies that only the 10.0.1.0/16 networkswill be permitted via incoming RIP updatesthrough interface serial 0. All other incomingRIP updates, including the 10.1.0.0/24 and 172.24.1.0/24 will befiltered. Since the10.0.1.0/24 is part of the 10.0.1.0/16 network, it will be allowed.

QUESTION: 184Which one of the following BGP prefix lists would you use if you wanted to deny thedefault route 0.0.0.0?

A. ip prefix-list abc deny 0.0.0.0/0B. ip prefix-list abc permit 0.0.0.0/32C. ip prefix-list abc deny 255.255.255.255/0D. ip prefix-list abc permit 255.255.255.255/32E. None of the other alternatives apply

Answer: A

Explanation:To deny the default route 0.0.0.0/0 use the following command: ip prefix-list abc deny0.0.0.0/0

Incorrect Answer:B, D: We are required to deny it, not permit it.C: This will effectively deny all routes, not just the default route.

QUESTION: 185Which of the following prefix-list statements would you enter if you wanted to permit allprefixes that fall between /8 and /24 on the 192.0.0.0 network?

A. ip prefix-list abc permit 192.0.0.0/8 ge 8 le 24B. ip prefix-list abc permit 192.0.0.0/8 ge 24 le 8C. ip prefix-list abc permit 192.0.0.0/24 ge 24 le 8

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D. ip prefix-list abc permit 192.0.0.0/24 ge 8 le 24

Answer: A

Explanation:When used with prefix lists, the “ge” means “greater than or equal to” and the term “le”means “less than or equal to.” Greater than (ge) 8 and less than (le) 24. An 8 bit subnetmask should also be used, since we are looking to match all prefixes beginning on theentire 192.X.X.X range.

QUESTION: 186You have a router that’s been configured with multiple IP routing protocols, and you’reinterested in checking out if and how inbound and outbound routing updates are beingfiltered. Which one of the following commands would list these filters?

A. show ipB. show ip routeC. show ip protocolsD. show ip interfaceE. show protocol filters

Answer: C

Explanation:The command show ip protocols command is used to display the parameters and currentstate of the activerouting protocol process. The information is presented on a routingprotocol basis and includes applied inboundand outbound filters.

Incorrect Answer:A: Show ip is an incomplete command.B: The show ip route command displays active routes, not information on filters.D: The show ip interface command lists a summary of an interface's IP information andstatus. However, itdoes not list the filters applied on a routing protocol basis.E: This is an invalid command.


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Based on the partial configuration file of router Company3, which statement is true?

A. Only traffic with a destination from 10.10.0.0/19 will be permitted.B. Router Company3 will accept only the 10.10.0.0/19 route from its BGP neighbor.C. Only traffic going to 10.10.0.0/19 will be permitted.D. Router Company3 will send only route 10.10.0.0/19 to its BGP neighbor.E. None of the other alternatives apply

Answer: B

Explanation:Distribute-list is used to permit or deny advertising the routes in association with anaccess-list. The distributelistcommand permits the routes as permitted by an access-list ordeny routes as denied by access-list either inthe inbound or outbound direction.In theexhibit, access-list has permitted only 10.10.0.0/19. All other routing entries will beimplicitly denied.So Companyg3 will accept only 10.10.0.0/19 routes from its BGP172.16.1.2 neighbor because distributelistcommand is applied into inbound direction.


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Exhibit:

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In this network, host CompanyA is a DNS server. Examine the Company1 configurationfile. On the basis of the information that is presented, which statement is true?

A. Route updates containing the DNS server address will be placed in the route table, buttraffic going to the DNS server will be denied.B. Route updates containing the DNS server address will be denied placement in the routetable.C. Route updates containing the DNS server address will be placed in the route table, buttraffic coming from the DNS server will be denied.D. Traffic going to the DNS server will be blocked at the S0/0 interface on the routerCompany1.E. None of the other alternatives apply.

Answer: C

Explanation:Distribute lists are used to deny routing updates for a particular network. In this example,since no distribute lists have been defined.the routing updates for the 10.1.1.0 network willbe allowed, but actual traffic from the DNS server will be denied due to access list 101.


Company2 Exhibit:

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Based on the information in the exhibit and the partial configuration file of Company2,which statement is true?

A. Companyg2 will not have the 10.0.0.0 network in its routing table.B. Companyg3 will not have the 192.168.10.0 network in its routing table.C. Companyg3 will be able to access the 10.0.0.0 network.D. Companyg3 will not have the 10.0.0.0 network in its routing table.E. Companyg2 and Companyg3 will not have the 10.0.0.0 network in their routing tables.F. None of the other alternatives apply

Answer: D

Explanation:You use the distribute-list command and link it to an ACL to complete the filtering ofrouting update traffic. In the exhibit a distribute-list is defined in the outbound direction ofs0/0, which is linked with access-list 10 where access-list 10 permitted only 192.168.0.00.0.0.255 and the implicit deny to all other. So Company2 sends only about 192.168.0.00.0.0.255 route to Company3 router.


Exhibit #2:

Part of the router configuration of Company2 is shown in the exhibit. The s0 interfaceconnects to the 192.168.5.0 network. Based on the information shown, select the correctstatement.

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A. Company2 will not advertise the 10.0.0.0/8 network because it is blocked by the ACL.B. The 10.0.0.0/8 network will not be advertised by Company2 because the networkstatement for the 10.0.0.0/8 network statement for the 10.0.0.0/8 network is missing fromCompany2.C. Traffic from the 172.16.0.0/16 network will be blocked by the ACL.D. Users on the 10.0.0.0/8 network can successfully ping users on the 192.168.5.0/24network, but users on the 192.168.5.0/24 cannot successfully ping users on the 10.0.0.0/8network.E. The 10.0.0.0/8 network will not be in the routing table on Company2.F. None of the other alternatives apply

Answer: A

Explanation:In this example, access-list 7 is used to specify which networks will be advertised out theinterface on the distribute list. Ths ACL only allows for the 172.16.0.0/16 to be advertisedout (everything else is denied by the implicit “deny all” statement in access lists), so10/0/0;0/8 will indeed be filtered and will not be advertised to any upstream routers.

QUESTION: 191What is the purpose of configuring the router as a PPPoE client?

A. for DSL connectivity and removing the need for the end-user PC to run the PPPoEclient softwareB. for connecting the router to a cable modem, which bridges the Ethernet frames from therouter to the cable modem termination systemC. to enable PPP session from the router to the termination device at the headend for metroEthernet connectivityD. to provide VPN access over L2TP

Answer: A

Explanation:PPPoE is widely used for digital subscriber line (DSL) internet browsing because thepublic telephone network uses ATM for its transport protocol; therefore, Ethernet framesmust be encapsulated in a protocol supported over both Ethernet and ATM.

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QUESTION: 192What is the international standard for transmitting data over a cable system?

A. PPPoEB. AAL5C. DOCSISD. CMTSE. IPTV

Answer: C

Explanation:DOCSIS is an international telecommunications standard that permits the addition of high-speed data transfer to an existing Cable TV (CATV) system.

QUESTION: 193You as a network engineer for Company.com. You study the exhibits carefully. A newTAC engineer came to you for advice. A GRE over IPsec tunnel was configured, but thetunnel is not coming up. What did the TAC engineer configure incorrectly?Network Topology Exhibit:


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A. The crypto map is not configured correctly.B. The OSPF network is not configured correctly.C. The crypto map is not applied to the correct interface.D. The crypto ACL is not configured correctly.

Answer: D

QUESTION: 194Which two methods use IPsec to provide secure connectivity from the Company branchoffice to the main office? (Choose two.)

A. MPLS VPNB. Virtual Tunnel Interface (VTI)C. PPPoED. DMVPNE. SSL VPNF. PPPoA

Answer: B, D

QUESTION: 195What is a key benefit of using a GRE tunnel to provide connectivity between branchoffices and headquarters?

A. open standardB. less overheadC. scalability

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D. granular QoS supportE. authentication, integrity checking, and confidentialityF. dynamic routing over the tunnel

Answer: F

QUESTION: 196Which of the following can you do to express an IPv6 address as efficiently as possible?(Select 2 choices.)

A. Replace every four-character group of zeros with double colons.B. Remove leading and trailing zeros from each four-character group.C. Remove only leading zeros from each four-character group.D. Remove only trailing zeros from each four-character group.E. Replace only one four-character group of zeros with a double colon.F. Replace one or more contiguous four-character groups of zeros with a double colon.

Answer: C, F

QUESTION: 197Which of the following statements are correct regarding EIGRP queries? (Select 2choices.)

A. EIGRP queries cannot propagate across autonomous systems.B. EIGRP queries require replies before the network will converge.C. EIGRP queries can be contained by disabling route summarization.D. EIGRP queries can be contained by creating stub routers.E. EIGRP queries prevent routers from becoming SIA.

Answer: B, D

QUESTION: 198Which of the following codes from the output of the show ip route command indicates thatthe route is a default route? (Select the best answer.)

A. EXB. *C. DD. S

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Answer: B

QUESTION: 199Which of the following ICMPv6 message types is used to query for the Layer 2 address ofa host? (Select the best answer.)

A. outer solicitationB. neighbor solicitationC. router advertisementD. neighbor advertisement

Answer: B

QUESTION: 200Which of the following must match for two directly connected routers running OSPF toestablish a neighbor adjacency? (Select 2 choices.)

A. area IDsB. process IDsC. router IDsD. hello timers

Answer: A, D

QUESTION: 201Which of the following could you do so that the routers can share redistributed routes?(Select 2 choices.)

A. Change the EIGRP router ID by issuing the eigrp router-id 1.2.3.4 command on eitherrouter.B. Change the loopback1 IP address by issuing the ip address 1.2.3.4 255.255.255.255command for the loopback1 interface on either router.C. Change the secondary IP address by issuing the ip address 172.16.2.2 255.255.255.0secondary command for the Fa0/1 interface on RouterB.D. Change the loopback0 IP address by issuing the ip address 1.2.3.4 255.255.255.255command for the loopback0 interface on either router.E. Create a different EIGRP AS by issuing the router eigrp 2 command on either router.

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Answer: A, B

QUESTION: 202Which of the following features belong to the Generic Routing Encapsulation (GRE)tunneling protocol? Each correct answer represents a complete solution. Choose all thatapply.

A. GRE provides explicit protection against recursive encapsulation.B. GRE tunnels are designed to be completely stateful.C. GRE provides implicit protection against recursive encapsulation.D. GRE supports multiprotocol tunneling.E. GRE is used for creating a virtual point-to-point link.F. GRE tunnels are designed to be completely stateless.

Answer: A, B, D, F

QUESTION: 203What administrative distance is assigned to external BGP routes by default? (Select thebest answer.)

A. 5B. 1C. 170D. 200E. 20F. 90

Answer: E

QUESTION: 204Which of the following statements is correct regarding EIGRP manual summarization?(Select the best answer.)

A. Manual summarization is configured in interface configuration mode.B. Manual summarization must occur on classful bit boundaries.C. Manual summarization is enabled by issuing the no ip summary-address eigrpcommand.D. Manual summarization is configured in global configuration mode.E. Manual summarization is enabled by issuing the no auto-summary command.

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Answer: A

QUESTION: 205Which of the following configurations is consistent with this routing protocol behavior?(Select the best answer.)

A. Area 2 is a stub area, and Area 3 is an NSSA.B. Area 2 is a stub area, and Area 3 is a normal area.C. Area 2 is a normal area, and Area 3 is a stub area.D. Area 2 is an NSSA, and Area 3 is a stub area.

Answer: D

QUESTION: 206You configure the routers on your network for OSPF operation. You want to configure thenetwork type so that all routers will automatically establish adjacencies with neighborrouters without requiring the manual configuration of neighbor commands. Additionally,you want DR elections to take place. Which of the following commands should you issuein interface configuration mode? (Select the best answer.)

A. ip ospf network non-broadcastB. ip ospf network point-to-multipoint non-broadcastC. ip ospf network point-to-pointD. ip ospf network point-to-multipointE. ip ospf network broadcast

Answer: E

QUESTION: 207Look at the following configuration below and select the statements that are true.RD2(config)#router ospf 100RD2(config-router)# distance 180 10.1.10.1 0.0.0.0 match-meRD2(config-router)#!RD2(config-router)#ip access-list standard match-meRD2(config-std-nacl)# permit host 172.16.0.0Choose two.

A. OSPF will have an AD of 180 for routes from 10.1.10.1 in the 172.16.0.0/16 range.B. The neighbor RID is 10.1.10.1C. OSPF will have an AD of 180 for all routes.D. The local RID is 10.1.10.1

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Answer: A, B

QUESTION: 208What will the AS Path look like to BGP speaking routers in AS 65101 to reach AS Path65401? Choose the best answer .

A. AS 65102 65300 65301 65401B. AS 65101 65102 65300 65301 65401C. AS 65102 65301 65401D. AS 65101 65102 65301 65401

Answer: C

QUESTION: 209Which IOS show command gives you the following SLA tracking information output tothe screen as shown below: Track 1Interface Serial0/1/0 ip routingIP routing is Up27 changes, last change 00:03:37Tracked by:1207165940Choose the best answer.

A. show ip sla statisticsB. show trackC. show interfaces dampeningD. show ip sla

Answer: B

QUESTION: 210When configuring EIGRP on new WAN technologies such as an MPLS VPN or MetroEthernet, it is important that an engineer understand what layer of the OSI model thesetechnologies function on to determine how EIGRP will form neighbor relationships. Fromthe choices below, choose the proper OSIlayer each WAN technology runs on. Choosetwo.

A. MPLS VPN is a layer 2 technology

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B. Metro Ethernet is a layer 2 technologyC. MPLS VPN is a layer 3 technologyD. Metro Ethernet is a layer 3 technologyE. MPLS VPN is a layer 4 technology

Answer: B, C

QUESTION: 211A router has been configured with OSPF authentication on interface fa0/0. The OSPFneighbor relationship is not forming. You issue a "debug ip ospf events" command and seethe following log message: 05:01:35: OSPF: Rcv pkt from 192.168.2.2, OSPF_VL0 :Mismatch Authentication type. Input packet specified type 0, we use type 1 Using thisinformation, which of the following is true? Choose the best answer.

A. Fa0/0 on the local router has the following configuration. ip ospf authentication type-1B. Fa0/0 on the local router has the following configuration. ip ospf authenticationC. Fa0/0 on the local router has the following configuration. ip ospf authentication nullD. Fa0/0 on the local router has the following configuration. ip ospf authenticationmessage-digest

Answer: B

QUESTION: 212Which of the following routing protocols are supported by the Enhanced Internet GatewayRouting Protocol (EIGRP)?Each correct answer represents a complete solution. Choose allthat apply.

A. Border Gateway ProtocolB. AppleTalk routing protocolC. Open Shortest Path First protocolD. IPX routing protocolsE. IP routing protocols

Answer: E, B, D

QUESTION: 213Which of the following commands correctly configures an IPv6 address on an interfaceand sets it to operate using RIPng with the name CCNP-lab? Choose the best answer.

A. Router(Config-if)# interface FastEthernet0/0

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Router(Config-if)# ipv6 address 2011::1/64Router(Config-if)# ipv6 rip CCNP-labB. Router(Config)# interface FastEthernet0/0Router(Config-if)# ipv6 address 2011::1/64Router(Config-if)# ipv6 rip CCNP-lab enableC. Router(Config-if)# interface FastEthernet0/0Router(Config-if)# ipv6 address 2011::1/64D. Router(Config)# interface FastEthernet0/0Router(Config-if)# ipv6 address 2011::1/64Router(Config-if)# ip ripng CCNP-lab enable

Answer: B

QUESTION: 214An engineer wants to redistribute OSPF into EIGRP. They log in to the boarder router thatruns bothSPF and EIGRP and execute the following commands:Router(config)#router eigrp 100Router(config-router)#redistribute ospf 2Router(config-router)#endRouter#Unfortunately, this did not cause OSPF routes to redistribute into EIGRP. What is likelythe problem? Choose two.

A. EIGRP needs to be configured with default metric values before it will redistributeOSPF .B. OSPF cannot be redistributed into EIGRP.C. OSPF must first be redistributed into static routes prior to being redistributed intoEIGRP.D. The OSPF process ID is something other than 2.

Answer: A, D

QUESTION: 215An engineer is trying to summarize the following networks using the "ip summary-addreseigrp" command:10.8.88.0/2510.8.89.48/2910.8.64.96/27Which network and subnet mask below would be the smallest EIGRP summary address toinclude all three subnets? Choose the best answer.

A. 10.8.64.0 255.255.224.0B. 10.8.64.0 255.255.128.0

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C. 10.8.64.0 255.255.192.0D. 10.8.0.0 255.255.192.0

Answer: A

QUESTION: 216Company uses EIGRP as the primary routing protocol in their network. How does EIGRPadvertise subnet masks for each destination network?

A. EIGRP advertises a fixed length subnet mask for each destination network.B. EIGRP advertises only a classful subnet mask for each destination network.C. EIGRP, like IGRP and RIP, does not advertise a subnet mask for each destinationnetwork.D. EIGRP advertises a prefix length for each destination network.E. None of the other alternatives apply

Answer: D

Explanation:Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco-proprietary routingprotocol based on IGRP. Unlike IGRP, which is a classful routing protocol, EIGRPsupports CIDR, allowing network designers to maximize address space by using CIDRand VLSM. Compared to IGRP, EIGRP boasts faster onvergence times, improvedscalability, and superior handling of routing loops. The prefix length field signifies thesubnet mask to be associated with the network number specified in the destination field.Thus, if an EIGRP router is configured as follows:• ip address 172.16.1.1 255.255.255.0it will advertise 172.16.1.0 with a prefix length of 24. Likewise, if the router is configuredas follows:• ip address 172.16.250.1 255.255.255.252 it will advertise 172.16.250.0 with a prefixlength of 30.

QUESTION: 217The Company network uses EIGRP. Identify three characteristics of EIGRP feasiblesuccessors? (Select three)

A. Traffic will be load balanced between feasible successors with the same advertiseddistance.B. If the advertised distance of the non-successor route is less than the feasible distance ofbest route, then that route is identified as a feasible successor.C. If the successor becomes unavailable, then the feasible successor can be usedimmediately without recalculating for a lost route.D. The feasible successor can be found in the routing table.

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E. A feasible successor is selected by comparing the advertised distance of a non-successorroute to the feasible distance of the best route.

Answer: B, C, E

Explanation:Once a neighbor relationship has been formed, called an Adjacency, the routers exchangerouting update information and each router builds its own topology table. The Updatescontain all the routes known by the sender. For each route, the receiving router calculates adistance for that route based on the distance that is conveyed and the cost to that neighborthat advertised the particular route. If the receiving router sees several routes to a particularnetwork with different metrics, then the route with the lowest metric becomes the FeasibleDistance (FD) to that network. The Feasible Distance is the metric of a network advertisedby the connected neighbor plus the cost of reaching that neighbor. This path with the bestmetric is entered into the routing table because this is the quickest way to get to thatnetwork. With the other possible routes to a particular network with larger metrics, thereceiving router also receives the Reported Distance (RD) to this network via other routers.The Reported Distance being the total metric along a path to a destination network asadvertised by an upstream neighbor. The Reported Distance for a particular route iscompared with the Feasible Distance that it already has for that route. If the ReportedDistance is larger than the Feasible Distance then this route is not entered into theTopology Table as a Feasible Successor. This prevents loops from occurring. If theReported Distance is smaller than the Feasible Distance, then this path is considered to bea Feasible Successor and is entered into the Topology table. The Successor for a particularroute is the neighbor/peer with the lowest metric/distance to that network. If the receivingrouter has a Feasible Distance to a particular network and it receives an update from aneighbor with a lower advertised distance (Reported Distance) to that network, then thereis a Feasibility Condition. In this instance, the neighbor becomes a Feasible Successor forthat route because it is one hop closer to the destination network. There may be a numberof Feasible Successors in a meshed network environment, up to 6 of them are entered intothe Topology table thereby giving a number of next hop choices for the local router shouldthe neighbor with the lowest metric fail. What you should note here, is that the metric for aneighbor to reach a particular network (i.e. the Reported Distance) must always be lessthan the metric (Feasible Distance) for the local router to reach that same network. Thisway routing loops are avoided. This is why routes that have Reported Distances larger thanthe Feasible Distance are not entered into the Topology table, so that they can never beconsidered as successors, since the route is likely to loop back through that local router.

Incorrect Answer:A: With EIGRP, traffic is load balanced across equal cost links in the routing table, but notbetween feasible successors.D: The feasible successors are found in the topology table, but not the active routing table.

Reference:http ://www.rhyshaden.com/eigrp.htm

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QUESTION: 218OSPF networks create Link State Advertisements (LSAs). What kind of LSA is conceivedby an Area Border Router (ABR) containing route summarization of area subnets?

A. Router link, type 1.B. Router link, type 8.C. Network summary link, type 3.D. AS external summary link, type 4.

Answer: C

Explanation:The network summary link entry is a LSA type 3 that is originated by ABRs. It describesthe links between the ABR and the internal routers of a local area. These entries areflooded throughout the backbone area to the other ABRs.

Incorrect Answer:A: Router link, LSA type 1 is generated by each router for each area it belongs to. Itdescribes the states of the router's link to the area.B: Router LSA is type 1.D. External link LSA is type 5.

QUESTION: 219When an OSPF ASBR announces external networks, what kind of LSA type does it use?

A. Type 1 LSAB. Type 2 LSAC. Type 3 LSAD. Type 4 LSAE. Type 5 LSA

Answer: E

Explanation:In OSPF, Type 5 LSA is used to announce external networks. The OSPF Router LSAtypes are described here:• Router LSA (type 1) - information about the router and its directly connected links;flooded only w/in the area

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• Network LSA (type 2) - information about a LAN and the routers connected to it;originated by the DR; flooded only w/in the area• Summary LSA (type 3) - describe networks reachable outside the area; originated by thearea border routers (ABR)• ASBR Summary LSA (type 4) – reachability information to the Autonomous SystemBorder Routers outside the area; originated by the ABRsExternal LSA (type 5) - information about destinations outside the OSPF domain;originated by the ASBRs; flooded throughout the whole network• Other LSA types exist for multicast information (type 6) and other extensions, includingNSSA area (type 7).

QUESTION: 220Router Company1 is configured for OSPF as shown below:router ospf 76network 172.22.23.0 0.0.0.0 area 1network 172.18.0.0 0.0.255.255area 0 area 0 range 172.18.0.0 255.255.0.0area 1 range 172.22.23.0 255.255.255.0Which of the following statements are true regarding the above configuration? (Selectthree)

A. The OSPF router ID is 76.B. This is an area border router.C. The designated router priority is 76.D. This router connects area 1 to the backbone area.E. Any router interfaces with an address of 172.18.x.x are in area 0.

Answer: B, D, E

Explanation:An interface may belong to only one area. If a router has multiple interfaces and if any ofthose interfaces belong to different areas, the router is considered as an area border router.The networks that follow the network command are connected to each other and Area O isalways the backbone area. Finally, the command “network 172.18.0.0 0.0.255.255 area 0”identifies that all interfaces with IP address of 172.18.0.0 area within area 0.

Incorrect Answer:A, C: The command router ospf 76 identifies the process ID as 76 and not the router IDnor the router priority. Catherine Paquet and Daine Teare, “Building Scalable CiscoNetworks” (Cisco Press 2001), pp 178-181.

QUESTION: 221

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Routers Company1 and Company2 are configured for BGP as shown below:RTR Company1router bgp 200neighbor 183.215.22.1 remote-as 200neighbor 183.215.22.1 update-source loopback 1RTR Company2router bgp 200neighbor 147.229.1.1 remote-as 200These two routers currently have an active BGP peering session between them and theyare able to pass routes to each other. Based on these configuration files, which of thefollowing are true? (Select three)

A. RTR Company1 and RTR Company2 are running IBGP inside AS 200B. The IP address of RTR Company1’s Loopback 1 interface is 147.229.1.1.C. The IP address of RTR Company1’s Loopback 1 interface is 183.215.22.1.D. RTR Company1 and RTR Company2 are running EBGP between the autonomoussystems.E. RTR Company1 has forced BGP to use the loopback IP address as the source in theTCP neighbor connection.

Answer: A, B, E

Explanation:A: The two statements that define a remote AS (autonomous) use the same AS number.Both routers must belong to the same AS and there IBGP is used.B: The IP address of the Company1 loopback address is 147.229.1.1 as specified in theneighbor statement of the Company2 router: neighbor 147.229.1.1 remote-as 200E: The “neighbor 183.215.22.1 update-source loopback 1” command issued at Company1makes Company1 use this loopback for the BGP connection to Company2. See Note 2below.Note 1: Syntax of neighbor command: Router(config-router)#neighbor {ip-address | peer-group- name} remote-as as-number This command specifies a BGP neighbor.Note 2: For iBGP, you might want to allow your BGP connections to stay up regardless ofwhich interface is used to reach a neighbor. To enable this configuration, you firstconfigure a loopback interface and assign it an IP address (neighbor 183.215.22.1 update-source loopback 1). Next, configure the BGP update source to be the loopback interface(we have to assume this step – it is not indicated by the exhibit). Finally, configure yourneighbor to use the address on the loopback interface (neighbor 147.229.1.1 remote-as200).

Incorrect Answer:C: 183.215.22.1 is the IP address of Company2, not Company1.

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D: There is only one AS and the routers belong to that AS. Within an AS IBGP is used,not EBGP.

QUESTION: 222To enable BGP tunneling over the Company IPv4 backbone, the IPv4 address192.168.30.1 is converted into a valid IPv6 address. Which three IPv6 addresses areacceptable formats for the IPv4 address? (Choose three.)

A. 192.168.30.1:0:0:0:0:0:0B. 0:0:0:0:0:0:192.168.30.1C. ::192.168.30.1D. C0A8:1E01::E. 192.168.30.1::F. ::C0A8:1E01

Answer: B, C, F

Explanation:Many transition strategies have been developed for IPv4 networks to migrate to IPv6service and for IPv6 networks to intercommunicate over IPv4 networks. Most of thesestrategies involve tunneling, dual stack, IPv4 Compatible IPv6 Address. A mechanismexists for creating IPv6 addresses that are compatible with IPv4. These addresses use 0s inthe first 96 bits of the address and one of the two formats for the remaining portion of theaddress. Here is the example of IPv4 10.10.100.16 address acceptable for IPv6 format:0:0:0:0:0:10:10:100:16Or ::10:10:100:16or::A:A:64:10So Answer B, C, F are the correct answers.

QUESTION: 223You are using multiple routing protocols in different Autonomous Systems (AS) within theCompany network domain. You need to redistribute between the systems. You are usingtwo-way redistribution but you want to ensure a loop free topology. Which action shouldhelp you avoid routing loop issues?

A. Manually configuring the administrative K-factorB. Manually configuring the administrative distanceC. Manually configuring the static routesD. Manually configuring the default gatewayE. None of the other alternatives apply

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Answer: B

Explanation:If a boundary router is running multiple IP routing protocols, then it may be possible thatthe router will learn about the same network from more than one routing protocol.Theadministrative distance of a routing protocol provides a rate of trustworthiness as a sourceof routing information. Administrative distance is an integer from 0 to 255. The lowestadministrative distance has the highest trust rating. An administrative distance of 255means the routing information source cannot be trusted at all and should be ignored. Anadministrative distance of zero is reserved for directly connected interfaces and willalways be preferred.Specifying administrative distance values enables the Cisco IOSsoftware to discriminate between sources of routing information. If two routes have thesame network number, and possibly subnet information, the IOS software always picks theroute whose routing protocol has the lowest administrative distance distance command isused to modify the default administrative distance. The distance command can also beapplied with optional arguments to make changes to selected routes based on where theyoriginate. The expanded syntax of the distance command is as follows: Router(config-router)#distance weight [source-ip-address source-mask (access-list-number | name)]

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