MANETconf: Configuration of Hosts in a Mobile Ad Hoc Network

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MANETconf: MANETconf: Configuration of Configuration of Hosts in a Mobile Ad Hoc NetworkHosts in a Mobile Ad Hoc Network

Authors:Authors: Sanket Nesargi & Ravi PrakashSanket Nesargi & Ravi Prakash

Originally Published:Originally Published: IEEE INFOCOM ’02, New York, June 2002

Presented By:Presented By: Michael Pincott Michael Pincott

Date:Date: July 1, 2003 July 1, 2003

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OutlineOutline

Background InformationBackground Information Topic PrimerTopic Primer System ModelSystem Model Related / Previous WorkRelated / Previous Work MANETconf ConceptMANETconf Concept MANETconf OperationMANETconf Operation Making MANETconf RobustMaking MANETconf Robust Security IssuesSecurity Issues SimulationsSimulations ConclusionsConclusions

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Background InformationBackground Information

Sanket NesargiSanket Nesargi– Received M.S. and Ph.D. in CS at University of Texas at DallasReceived M.S. and Ph.D. in CS at University of Texas at Dallas– Worked at Nortel for a few yearsWorked at Nortel for a few years

– Researches:Researches:• Mobile Computing/Wireless NetworksMobile Computing/Wireless Networks

– Network Service ProtocolsNetwork Service Protocols– Protocol Design FrameworksProtocol Design Frameworks– SecuritySecurity

• Transport/Network Layers in Fixed and Wireless NetworksTransport/Network Layers in Fixed and Wireless Networks• Group CommunicationGroup Communication• Sensor NetworksSensor Networks• Peer-to-Peer SystemsPeer-to-Peer Systems• BioinformaticsBioinformatics

– Personals:Personals:• Moving from “Hair Metal” into Pink Floyd, Led Zeppelin, Rainbow, Deep Purple• Rides a Kawasaki Ninja ZX 6 motorcycle• Loves his BMW 323i• Plays Squash, Badminton, Cricket• His website at UTD is called “The Dark Dungeon”

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Background InformationBackground Information

Ravi PrakashRavi Prakash– Received Ph.D. in CS at The Ohio State Received Ph.D. in CS at The Ohio State

University in 1996University in 1996

– Researches:Researches:• Mobile ComputingMobile Computing

– Location ManagementLocation Management– Mobile-TCPMobile-TCP– Cell PlanningCell Planning– Channel AllocationChannel Allocation

• Checkpointing and RecoveryCheckpointing and Recovery• Causally and Totally Ordered Causally and Totally Ordered

Message DeliveryMessage Delivery• Clocks and Dependency TrackingClocks and Dependency Tracking

– Personals:Personals:• Nesargi’s AdvisorNesargi’s Advisor• Big Robert De Niro fanBig Robert De Niro fan• Toastmaster International MemberToastmaster International Member• He “comes in peace and wants to He “comes in peace and wants to

make the world a happy place.”make the world a happy place.”

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MANETs: PrimerMANETs: Primer

Typical Wireless Typical Wireless Networks:Networks:

– Wireless Server Wireless Server Assigns DHCP, Assigns DHCP, IP,DNS, netmaskIP,DNS, netmask

– Data is routed Data is routed through serverthrough server

– Wireless Server may Wireless Server may be Internet gatewaybe Internet gateway

Laptop computer

IBM Compatible

Wireless Server

Laptop computer

Laptop computer

Laptop computer

Laptop computer

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MANETs: PrimerMANETs: Primer

MANET (Mobile MANET (Mobile Ad Hoc Network):Ad Hoc Network):

– Group of mobile, Group of mobile, wireless nodes wireless nodes working working cooperatively and cooperatively and spontaneouslyspontaneously

– Devoid of fixed Devoid of fixed infrastructure or infrastructure or central central administrationadministration

Laptop computer

IBM Compatible

Laptop computer

Laptop computer

Laptop computer

Laptop computer

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System ModelSystem Model

Without centralized servers, unconfigured Without centralized servers, unconfigured nodes joining the MANET must be assigned nodes joining the MANET must be assigned a unique IP addresses.a unique IP addresses.

Hosts already in the MANET must be Hosts already in the MANET must be responsible for uniquely configuring hosts responsible for uniquely configuring hosts wishing to join the MANET.wishing to join the MANET.

Hosts in the MANET must be responsible for Hosts in the MANET must be responsible for allowing graceful and abrupt host departures.allowing graceful and abrupt host departures.

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System ModelSystem Model

In IPv4, the MANET can In IPv4, the MANET can use:use:

– 10.0.0.0 – 10.255.255.25510.0.0.0 – 10.255.255.255– 172.16.0.0 – 172.31.255.255172.16.0.0 – 172.31.255.255– 192.168.0.0 – 192.168.255.255192.168.0.0 – 192.168.255.255

Nodes communicate through Nodes communicate through the exchange of IP packets.the exchange of IP packets.

Hosts of edges of MANET Hosts of edges of MANET may not be directly may not be directly reachable. MANET nodes reachable. MANET nodes must behave as routers and must behave as routers and forward packets from the forward packets from the source to the destination.source to the destination.

Laptop computer

IBM Compatible

Laptop computer

Laptop computer

Laptop computer

Laptop computer

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Related/Previous WorkRelated/Previous Work

Zeroconf Working Group:Zeroconf Working Group:– Attacks similar problem of network configuration Attacks similar problem of network configuration

with the lack of dedicated servers.with the lack of dedicated servers.

Assigns unique IPs to nodes in:Assigns unique IPs to nodes in:– Single network segments where all nodes can Single network segments where all nodes can

directly communicate.directly communicate.– Multiple segments connected to the same router.Multiple segments connected to the same router.

Limits the flexibility of Ad Hoc NetworksLimits the flexibility of Ad Hoc Networks

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PMWRS (Perkins, Malinen, Wakikawa, Royer, Sun):PMWRS (Perkins, Malinen, Wakikawa, Royer, Sun):– Similar to Zeroconf.Similar to Zeroconf.

– Performs duplicate address detection through multiple rounds of MANET-Performs duplicate address detection through multiple rounds of MANET-wide flooding.wide flooding.

PMWRS Limitations:PMWRS Limitations:– Uses AREQ and AREP.Uses AREQ and AREP.

– Tied to underlying routing protocol as it specifies the routes to be used by its Tied to underlying routing protocol as it specifies the routes to be used by its messages.messages.

– Uses 169.254.*.* IP block. Routers drop packets! This limits hosts ability to Uses 169.254.*.* IP block. Routers drop packets! This limits hosts ability to route packets after configured.route packets after configured.

– Network selects a candidate IP for the host joining the network. Checks for Network selects a candidate IP for the host joining the network. Checks for conflicts by polling hosts in the network. Timeout delays and retry constants conflicts by polling hosts in the network. Timeout delays and retry constants are limiting when the size/shape of network is unknown.are limiting when the size/shape of network is unknown.

– If multiple hosts request an IP concurrently, PMWRS may assign two hosts If multiple hosts request an IP concurrently, PMWRS may assign two hosts the same IP.the same IP.

– Much of the 169.254.*.* address block is reserved by IETF for future use.Much of the 169.254.*.* address block is reserved by IETF for future use.

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Hardware Based Addressing:Hardware Based Addressing:

– Use the “unique” hardware address of a card to help uniquely assign Use the “unique” hardware address of a card to help uniquely assign IPs (MAC address in Ethernet Adapters).IPs (MAC address in Ethernet Adapters).

Hardware Based Addressing Limitations:Hardware Based Addressing Limitations:

– MANET nodes not restricted to NICs with unique MAC addresses.MANET nodes not restricted to NICs with unique MAC addresses.

– Not all NICs have unique addresses.Not all NICs have unique addresses.

– Some devices allow for the reprogramming of the MAC address.Some devices allow for the reprogramming of the MAC address.

– Nodes can be easily determined by tracking the MAC. Security?Nodes can be easily determined by tracking the MAC. Security?

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MANETconf ConceptMANETconf Concept

Assign unique IP addresses to hosts despite dynamic Assign unique IP addresses to hosts despite dynamic topology by employing a mutual exclusion algorithm.topology by employing a mutual exclusion algorithm.

– A node proposes an IP address for an incoming host.A node proposes an IP address for an incoming host.

– If proposed IP is accepted by all other hosts, the incoming host is If proposed IP is accepted by all other hosts, the incoming host is assigned that IP.assigned that IP.

Proposed solution is a modified version of the Ricart-Proposed solution is a modified version of the Ricart-Agrawala algorithm.Agrawala algorithm.

– RA Algorithm modification include the ability to be flexible to RA Algorithm modification include the ability to be flexible to changing network topology and a changing number of users in the changing network topology and a changing number of users in the network.network.

– RAs inflexibility for topology changes is the motivation for RAs inflexibility for topology changes is the motivation for MANETconf.MANETconf.

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MANETconf OperationMANETconf Operation

MANET Initialization:MANET Initialization:

– RequestorRequestor broadcasts its broadcasts its Neighbor_QueryNeighbor_Query message message and starts its and starts its Neighbor_reply_timerNeighbor_reply_timer..

– Very first requestor will not Very first requestor will not receive any replied. receive any replied.

– When timer expires, the When timer expires, the requestor will try again and if requestor will try again and if there is still no response it there is still no response it assumes it is the first node in assumes it is the first node in the MANET.the MANET.

Node j

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New Node Joining the MANET:New Node Joining the MANET:

– Node i wishes to join the network. Node i wishes to join the network. Node j is currently the only node in Node j is currently the only node in the network.the network.

– i broadcasts the i broadcasts the Neighbor_Query Neighbor_Query message.message.

– j responds before the timer expires. j responds before the timer expires.

– i selects j as its i selects j as its initiatorinitiator and ignores and ignores any other any other Neighbor_RepliesNeighbor_Replies it may it may receive.receive.

– i sends j a i sends j a Requester_RequestRequester_Request message.message.

Node iNode j

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New Node Joining the MANET (cont’d):New Node Joining the MANET (cont’d):

– j polls other nodes in the network asking if IP j polls other nodes in the network asking if IP x is available for use. Other nodes check x is available for use. Other nodes check their Allocated IP and Allocated_pending their Allocated IP and Allocated_pending lists.lists.

– If all responses to j are affirmative, j:If all responses to j are affirmative, j:• Assigns IP x to node i.Assigns IP x to node i.• Adds IP x to its Allocated IP list.Adds IP x to its Allocated IP list.• Floods this information throughout the Floods this information throughout the

MANET so other hosts can also transfer IP x MANET so other hosts can also transfer IP x to their Allocated IP lists.to their Allocated IP lists.

– If at least one host responses with a If at least one host responses with a negative, the entire process is repeated with negative, the entire process is repeated with a new IP (x’).a new IP (x’).

– Process is repeated until node i is assigned Process is repeated until node i is assigned an IP or the an IP or the initiator_request_retryinitiator_request_retry number is number is exceeded. j then notifies i with a failure exceeded. j then notifies i with a failure message stating that no resources are message stating that no resources are available.available.

Node iNode j

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Concurrent Address Initiation:Concurrent Address Initiation:

– Nodes a and e wishes to Nodes a and e wishes to concurrently join the network.concurrently join the network.

– If the two initiators (b and d) chose If the two initiators (b and d) chose unique IPs for a and e, there is no unique IPs for a and e, there is no conflict.conflict.

– If initiators b and d happen to If initiators b and d happen to chose the same IP for a and e, the chose the same IP for a and e, the initiators IP will be used to set initiators IP will be used to set priority. The higher priority initiator priority. The higher priority initiator will receive the affirmative ack and will receive the affirmative ack and the lower priority initiator will the lower priority initiator will receive the negative ack. receive the negative ack.

Node eNode d

Node a

Node c

Node f

Node b

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Graceful Departure of Graceful Departure of Node:Node:

– Node i wishes to depart the Node i wishes to depart the network and relinquish its IP network and relinquish its IP before leaving the network.before leaving the network.

– i broadcasts the i broadcasts the Address_Cleanup Address_Cleanup message.message.

– All nodes in the network All nodes in the network remove the used IP from their remove the used IP from their Allocated IP list. Allocated IP list.

Node iNode j

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Making MANETconf RobustMaking MANETconf Robust

Abrupt or Ungraceful Node Departure:Abrupt or Ungraceful Node Departure:

– Node a crashes or ungracefully leaves the Node a crashes or ungracefully leaves the network.network.

– Node e wishes to join the network. It selects Node e wishes to join the network. It selects node d as its initiator.node d as its initiator.

– During node d’s initialization process, it During node d’s initialization process, it sends sends Initiator_RequestInitiator_Request messages to all the messages to all the IPs in its Allocated IP list.IPs in its Allocated IP list.

– Node a will fail to respond to the Node a will fail to respond to the Initiator_Request message.Initiator_Request message.

– Node d then sends an individual Node d then sends an individual Initiator_RequestInitiator_Request message to just node a. message to just node a. Node d will wait until its Node d will wait until its request_reply_timer request_reply_timer expires again. It will retry again based on expires again. It will retry again based on the threshold set by the threshold set by request_reply_retryrequest_reply_retry..

– With no response from node a, node d With no response from node a, node d sends an sends an Address_Cleanup Address_Cleanup message message throughout the MANET to release node A’s throughout the MANET to release node A’s IP.IP.

Node eNode d

Node a

Node c

Node f

Node b

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Requestor Migration:Requestor Migration:

– Node a wishes to join the network. Node a wishes to join the network. It selects b as its initiator.It selects b as its initiator.

– Node a migrates and is unable to Node a migrates and is unable to communicate with b. Node a now communicate with b. Node a now chooses c as its initiator.chooses c as its initiator.

– Node a informs c of its previous Node a informs c of its previous attempt to request an IP from b.attempt to request an IP from b.

– Node c sends node b a message Node c sends node b a message informing b of node a’s migration.informing b of node a’s migration.

– Node b still queries for an IP for Node b still queries for an IP for node a. When node b arrives at a node a. When node b arrives at a valid IP for node a, the result is valid IP for node a, the result is sent to node c and node c initiates sent to node c and node c initiates node a.node a.

Node d

Node a

Node c

Node b

Node dNode aNode c

Node b

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Initiator Crash:Initiator Crash:

– Node a wishes to join the network. Node a wishes to join the network. It selects b as its initiator.It selects b as its initiator.

– In the middle of the configuration In the middle of the configuration process, node b crashes.process, node b crashes.

– Eventually node a’s Eventually node a’s Address_allocation_timerAddress_allocation_timer will will timeout. Node a will then perform timeout. Node a will then perform another another Neighbor_queryNeighbor_query and select and select a new initiator if one can be a new initiator if one can be reached.reached.

– Any other nodes that reserved an Any other nodes that reserved an IP from node b’s address request IP from node b’s address request will eventually time out and the IP will eventually time out and the IP will be flushed from the will be flushed from the Allocated_Pending lists.Allocated_Pending lists.

Node eNode d

Node a

Node c

Node f

Node b

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Network Splits:Network Splits:

– The link between nodes c and d The link between nodes c and d fails. The network splits into two fails. The network splits into two networks.networks.

– All nodes in one partition can All nodes in one partition can assume that the nodes in the other assume that the nodes in the other partition have departed partition have departed ungracefully and cleaned up ungracefully and cleaned up accordingly.accordingly.

Node eNode d

Node a

Node c

Node f

Node b

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Partition Detection:Partition Detection:

– During a network split, what prevents an During a network split, what prevents an entering node on one partition from entering node on one partition from assuming the IP of a node on a second assuming the IP of a node on a second partition?partition?

– Partitions keep two identifiers – lowest Partitions keep two identifiers – lowest partition IP address and UUID.partition IP address and UUID.

– One partition has the node with the lowest IP One partition has the node with the lowest IP address. Nodes in this parent partition clean address. Nodes in this parent partition clean up the addresses from the second partition.up the addresses from the second partition.

– Clean up is also performed in the second Clean up is also performed in the second partition if a node requests an IP address. partition if a node requests an IP address. As the lowest IP in the parent node are As the lowest IP in the parent node are unobtainable, nodes in the second partition unobtainable, nodes in the second partition determine what IP address is the lowest determine what IP address is the lowest number. This lowest IP address node then number. This lowest IP address node then floods the partition and all nodes in that floods the partition and all nodes in that partition then know which node is the partition then know which node is the partition identifier.partition identifier.

Node eNode d

Node a

Node c

Node f

Node b

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Partition Detection (cont’d):Partition Detection (cont’d):

– If no IP address assignment If no IP address assignment is initiated on the second is initiated on the second partition, a clean up is never partition, a clean up is never triggered and the split is not triggered and the split is not detected.detected.

– In this case, if the lowest IP in In this case, if the lowest IP in tables become unreachable tables become unreachable after a number of retries a after a number of retries a cleanup can be initiated.cleanup can be initiated.

– Methods work even if Methods work even if network is partitioned into network is partitioned into multiple partitions.multiple partitions.

Node eNode d

Node a

Node c

Node f

Node b

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Security IssuesSecurity Issues

Susceptible to DOS attacksSusceptible to DOS attacks

– A rogue node could act as an initiator and effectively allocate all free IPs to A rogue node could act as an initiator and effectively allocate all free IPs to phantom nodes phantom nodes and prevent valid nodes from joining the network.and prevent valid nodes from joining the network.

– The rogue node can also respond to requests on behalf of the phantoms to The rogue node can also respond to requests on behalf of the phantoms to prevent clean ups.prevent clean ups.

Susceptible to Malicious Clean up MessagesSusceptible to Malicious Clean up Messages

– A rogue node could clean up the IPs of valid nodes and disconnect them A rogue node could clean up the IPs of valid nodes and disconnect them from the network. If this happens to an initiator, duplicate IPs could exist.from the network. If this happens to an initiator, duplicate IPs could exist.

Authors claim that their proposed solution is Authors claim that their proposed solution is only as insecureonly as insecure as other as other solutions and protocols such as ARP and RARP.solutions and protocols such as ARP and RARP.

Resolution to the above attacks can be achieved with the use of digital Resolution to the above attacks can be achieved with the use of digital certificates from a trusted Authentication Server.certificates from a trusted Authentication Server.

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SimulationsSimulations

Performed on ns-2 (ver2.1b6a) with CMU Performed on ns-2 (ver2.1b6a) with CMU extensions to support ad hoc networks.extensions to support ad hoc networks.

Simulations for related approaches (Zeroconf, etc) Simulations for related approaches (Zeroconf, etc) are not performed due to their “deterministic latency are not performed due to their “deterministic latency and number of messages that can be computed and number of messages that can be computed theoretically.”theoretically.”

Simulations do not implement support for handling Simulations do not implement support for handling partitioning.partitioning.

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MANET is modelled with moving nodes. Nodes pick a random coordinate, move at a MANET is modelled with moving nodes. Nodes pick a random coordinate, move at a speed of 5 m/s, stop at the destination for 10s, then repeat the process.speed of 5 m/s, stop at the destination for 10s, then repeat the process.

Maximum number of nodes is 40, 50, 60, and 80.Maximum number of nodes is 40, 50, 60, and 80.

Maximum node density is one node per 0.02kmMaximum node density is one node per 0.02km22..

For 40, 60, and 80 node simulations, simulations are started with 25, 35, and 45 pre-For 40, 60, and 80 node simulations, simulations are started with 25, 35, and 45 pre-configured nodes respectively. configured nodes respectively.

Node arrival times uniformly distributed in the range 0 – 70s.Node arrival times uniformly distributed in the range 0 – 70s.

Node lifetime varies between 0-1000s, 0-2000s, and 0-15000s.Node lifetime varies between 0-1000s, 0-2000s, and 0-15000s.

Graceful departures varied between 75% and 100%.Graceful departures varied between 75% and 100%.

Underlying routing protocol is DSDV.Underlying routing protocol is DSDV.

No arrivals accepted in the first 200s to allow nodes to set up routing tables.No arrivals accepted in the first 200s to allow nodes to set up routing tables.

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75% graceful and 25% abrupt 75% graceful and 25% abrupt departures.departures.

Most addresses are allocated in Most addresses are allocated in under 0.5sunder 0.5s

5s allocation attempts correspond to 5s allocation attempts correspond to unanswered initiator requests and unanswered initiator requests and are consistent with the numbers set are consistent with the numbers set in the in the initiator_request_timerinitiator_request_timer field. field.

10s allocation attempts correspond 10s allocation attempts correspond to situations where abrupt departure to situations where abrupt departure nodes were cleaned up. nodes were cleaned up.

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100% graceful departures.100% graceful departures.

Latency is high for some Latency is high for some address allocation attempts address allocation attempts due to packet loss.due to packet loss.

Only the results of the Only the results of the samples that are not dropped samples that are not dropped are shown.are shown.

Time required for address Time required for address allocation increases with the allocation increases with the number of nodes in the number of nodes in the network.network.

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Broadcast:Broadcast:

– Initiator_RequestInitiator_Request– Address_CleanupAddress_Cleanup– Other Flood MessagesOther Flood Messages

Multicast:Multicast:

– Messages sent to nodes that fail Messages sent to nodes that fail to respond to to respond to Initiator_RequestInitiator_Request messages.messages.

Unicast:Unicast:

– All communications directed All communications directed back to the initiator.back to the initiator.

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ConclusionsConclusions

MANETconf allows for dynamic allocation of MANETconf allows for dynamic allocation of IPs in a Mobile Ad Hoc Network without the IPs in a Mobile Ad Hoc Network without the need for a centralized server running DHCP.need for a centralized server running DHCP.

Proposed solution is tolerant to splits and Proposed solution is tolerant to splits and merges and can tolerate message loss.merges and can tolerate message loss.

Reasonable overhead.Reasonable overhead.

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Questions?Questions?

Documents

MANETconf: Configuration of Hosts in a Mobile Ad Hoc Network