1

2

Cisco IOS File System and Devices

3

Managing Cisco IOS Images

4

wg_ro_a#show flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin

[10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)

Verifying Memory Image Filenames

5

Creating a Software Image Backup

6

Upgrading the Image from the Network

7

LAB

Install TFTP server on a virtual machineConnect the machine to a RouterTo see the content of Flash file#show FlashTo copy flash

#Copy flash tftp supply IP address of TFTP Server and file name

To copy running-configuration#copy running-config tftpsupply IP address of TFTP Server and file name

8

Resolving Host Names

To use a hostname rather than an IP address to connect to a remote device

Two ways to resolve hostnames to IP addresses– building a host table on each router– building a Domain Name System (DNS)

server

9

Resolving Host Names

Building a host table

ip host host_name ip_addressR1(config)#ip host com1 10.0.0.1

R1(config)#ip host com2 10.0.0.2

To view tableR1#show hosts

To verify that the host table resolves names, try ping hostnames at a router prompt.

10

Password Recovery

Normal Boot SequencePOSTBootstrapIOSStartupRunning

This setup is decided by configuration register value

11

Configuration Register

1415 13 12 1011 9 8 67 5 4 23 1 0

Default 00 1 0 00 0 1 00 0 0 00 1 0 2102

48 2 1 48 2 1 48 2 1 48 2 1

Bit

Decimal

This means that bits 13, 8, and 1 are on.To ignore NVRAM the 6th bit should be made ONWhen the 6th bit is turned on the value will be 2142

12

Password Recovery

Show version will give configuration register value

Password is stored in NVRAMTo by pass NVRAM during boot sequence

we need to change the configuration register value

To change the CR values press Ctr+Break and go to ROM monitor mode

13

Password Recovery

Router 2500 o/r 0x2142 iRouter 2600 confreg 0x2142>reset

14

15

WAN vs LAN

Distance between WAN and LANWAN speed is lessWAN is leased from Service provider

16

Remote Access Overview

A WAN is a data communications network covering a relatively broad geographical area.

A network administrator designing a remote network must weight issues concerning users needs such as bandwidth and cost of the variable available technologies.

17

WAN Overview

Service Provider

WANs connect sites Connection requirements vary depending on user

requirements and cost

18

WAN technology/terminology

Devices on the subscriber premises are called customer premises equipment (CPE).

The subscriber owns the CPE or leases the CPE from the service provider. A copper or fiber cable connects the CPE to the service provider’s nearest exchange or

central office (CO). A central office (CO) is sometimes referred to as a point of presence (POP)

This cabling is often called the local loop, or "last-mile".

CPE (Customer Premises Equipment) are equipments located at the customer’s site, they are owned, operated and managed by the customer.

19

WAN technology/terminology

A demarcation point is where customer premises equipment (CPE) ends, and local loop begins.

The local loop is the cabling from demarcation point to Central Office (CO).

20

WAN technology/terminology

Devices that put data on the local loop are called data communications equipment (DCE).

The customer devices that pass the data to the DCE are called data terminal equipment (DTE).

The DCE primarily provides an interface for the DTE into the communication link on the WAN cloud.

The DTE/DCE interface uses various physical layer protocols, such as V.35.

These protocols establish the codes and electrical parameters the devices use to communicate with each other.

21

WAN Devices

Modems transmit data over voice-grade telephone lines by modulating and demodulating the signal.

The digital signals are superimposed on an analog voice signal that is modulated for transmission.

The modulated signal can be heard as a series of whistles by turning on the internal modem speaker.

At the receiving end the analog signals are returned to their digital form, or demodulated

22

WANs - Data Link Encapsulation

The data link layer protocols define how data is encapsulated for transmission to remote sites, and the mechanisms for transferring the resulting frames.

A variety of different technologies are used, such as ISDN, Frame Relay or Asynchronous Transfer Mode (ATM).

These protocols use the same basic framing mechanism, high-level data link control (HDLC)

23

WAN Technologies Overview

Covers a relative broad area

Use transmission facilities leased from service provider

Carries different traffic (voice, video and data)

Dedicated• T1, E1, T3,

E3• DSL• SONET

Analog• Dial-up

modems• Cable

modems• Wireless

Switched

Circuit Switched• POTS• ISDN

Packet Switched• X.25• Frame Relay•ATM

24

Dedicated Digital Services

Dedicated Digital Services provide full-time connectivity through a point-to-point link

T series in U.S. and E series in EuropeUses time division multiplexing and

assign time slots for transmissions– T1 = 1.544 Mbps E1 = 2.048 Mbps– T3 = 44.736 Mbps E3 = 34.368 Mbps

25

Digital Subscriber Lines

Digital Subscriber Line (DSL) technology is a broadband technology that uses existing twisted-pair telephone lines to transport high-bandwidth data to service subscribers.

The two basic types of DSL technologies are asymmetric (ADSL) and symmetric (SDSL).

All forms of DSL service are categorized as ADSL or SDSL and there are several varieties of each type.

Asymmetric service provides higher download or downstream bandwidth to the user than upload bandwidth.

Symmetric service provides the same capacity in both directions.

26

Analog Services

• Dial-up Modems (switched analog)• Standard that can provides 56 kbps download speed and

33.6 kbps upload speed.• With the download path, there is a digital-to-analogue

conversion at the client side.• With the upload path, there is a analogue-to-digital

conversion at the client side.

27

Cable Modems (Shared Analog)

Cable TV provides residential premises with a coaxial cable that has a bandwidth of 750MHz

The bandwidth is divided into 6 MHz band using FDM for each TV channel A "Cable Modem" is a device that allows high-speed data access (Internet)

via cable TV network. A cable modem will typically have two connections because a splitter

delivers the TV bands to TV set and the internet access bands to PC via a cable box

The splitter delivers the TV bands to TV set and the internet access bands

to PC via a cable box

28

Wireless

TerrestrialBandwidths typically in the 11 Mbps range Cost is relatively lowLine-of-sight is usually requiredUsage is moderate

SatelliteCan serve mobile users and remote usersUsage is widespreadCost is very high

29

Circuit Switched Services

Integrated Services Digital Network (ISDN) Historically important--first dial-up digital service Max. bandwidth = 128 kbps for BRI (Basic Rate

Interface) 2 B channels @ 64kps and 1 D channel @ 16kps B channels are voice/data channels; D for signaling

B

BD

30

Integrated Services Digital Network

32

WAN Connection Types

Leased linesIt is a pre-established WAN communications

path from the CPE, through the DCE switch, to the CPE of the remote site, allowing DTE networks to communicate at any time with no setup procedures before transmitting data.

Circuit switchingSets up line like a phone call. No data can

transfer before the end-to-end connection is established.

33

WAN Connection Types

• Packet switchingWAN switching method that allows you to

share bandwidth with other companies to save money. As long as you are not constantly transmitting data and are instead using bursty data transfers, packet switching can save you a lot of money.

However, if you have constant data transfers, then you will need to get a leased line.

Frame Relay and X.25 are packet switching technologies.

34

Defining WAN Encapsulation Protocols

Each WAN connection uses an encapsulation protocol to encapsulate traffic while it crossing the WAN link.

The choice of the encapsulation protocol depends on the underlying WAN technology and the communicating equipment.

35

Defining WAN Encapsulation Protocols

Typical WAN encapsulation types include the following:

Point-to-Point Protocol (PPP)Serial Line Internet Protocol (SLIP)High-Level Data Link Control Protocol (HDLC)X.25 / Link Access Procedure Balanced (LAPB)Frame RelayAsynchronous Transfer Mode (ATM)

36

Determining the WAN Type to Use

AvailabilityEach type of service may be available in

certain geographical areas. Bandwidth

Determining usage over the WAN is important to evaluate the most cost-effective WAN service.

CostMaking a compromise between the traffic you

need to transfer and the type of service with the available cost that will suit you.

37

Max. WAN Speeds for WAN Connections

WAN TypeMaximum Speed

Asynchronous Dial-Up 56-64 Kbps

X.25, ISDN – BRI 128 Kbps

ISDN – PRI E1 / T1

Leased Line / Frame Relay E3/T3

38

Leased Line

Circuit-switched

PPP, SLIP, HDLC

HDLC, PPP, SLIP

Packet-switched

X.25, Frame Relay, ATM

Typical WAN Encapsulation Protocols: Layer 2

Telephone

Company

Service

Provider

39

WAN Protocols

• Point to Point - HDLC, PPP• Multipoint - Frame Relay, X.25 and ATM

E0 S0 S0

WAN

LANNetwork

Datalink

Physical

• HDLC – Proprietary – cisco device default

• PPP - Open

41

HDLC Command

Router(config-if)#encapsulation hdlc

• Enable hdlc encapsulation• HDLC is the default encapsulation on

synchronous serial interfaces

42

PPP Encapsulation

PPP is open standardHDLC is only for encapsulationPPP provides encapsulation and authenticationPPP is made up of LCP and NCPLCP is for link control and NCP for multiple protocol support

and call back

Link setup and control using LCP in PPP

An Overview of PPP

43

Feature How It Operates Protocol

Authentication PAP

CHAPPerform Challenge Handshake

Require a password

CompressionCompress data at source; reproduce data at destination

Error Detection

Avoid frame looping

Monitor data dropped on link

Multilink Load balancing across multiple links

Multilink Protocol (MP)

PPP LCP Configuration Options

44

PPP Authentication Overview

Two PPP authentication protocols: PAP and CHAP

PPP Session Establishment1 Link Establishment Phase2 Optional Authentication Phase3 Network-Layer Protocol Phase

Dialup or Circuit-Switched

Network

45

• Passwords sent in clear text

Selecting a PPP Authentication Protocol

Remote Router(SantaCruz)

Central-Site Router (HQ)

Hostname: santacruzPassword: boardwalk

username santacruzpassword boardwalk

PAP 2-Way Handshake

“santacruz, boardwalk”“santacruz, boardwalk”

Accept/RejectAccept/Reject

46

Selecting a PPP Authentication Protocol

(cont.)Remote Router

(SantaCruz)Central-Site Router

(HQ)

Hostname: santacruzPassword: boardwalk

username santacruzpassword boardwalk

CHAP3-Way Handshake

ChallengeChallenge

ResponseResponse

Accept/RejectAccept/Reject

•Use “secret” known only to authenticator and peer

47

Configuring PPP and Authentication Overview

ServiceProvider

Verify who you are.

Router to Be Authenticated(The router that initiated the call.)

ppp encapsulation

hostname username / password ppp authentication

Authenticating Router(The router that received the call.)

ppp encapsulation

hostname username / password ppp authentication

Enabling PPP

Enabling PPP Authentication

Enabling PPP

Enabling PPP Authentication

48

Configuring PPP

Router(config-if)#encapsulation ppp

• Enable PPP encapsulation

49

Configuring PPP Authentication

Router(config)#hostname name

• Assigns a host name to your router

Router(config)#username name password password

• Identifies the username and password of authenticating router

50

Configuring PPP Authentication

(cont.)

Router(config-if)#ppp authentication{chap | chap pap | pap chap | pap}

• Enables PAP and/or CHAP authentication

51

Configuring CHAP Example

• hostname R1• username R2 password cisco• !• int serial 0• ip address 10.0.1.1 255.255.255.0• encapsulation ppp• ppp authentication CHAP

• hostname R1• username R2 password cisco• !• int serial 0• ip address 10.0.1.1 255.255.255.0• encapsulation ppp• ppp authentication CHAP

hostname R2username R1 password cisco!int serial 0 ip address 10.0.1.2 255.255.255.0 encapsulation ppp ppp authentication CHAP

hostname R2username R1 password cisco!int serial 0 ip address 10.0.1.2 255.255.255.0 encapsulation ppp ppp authentication CHAP

R1 R2PSTN/ISDN

52

Verifying HDLC and PPP Encapsulation Configuration

Router#show interface s0Serial0 is up, line protocol is up Hardware is HD64570 Internet address is 10.140.1.2/24 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set, keepalive set (10 sec) LCP Open Open: IPCP, CDPCP Last input 00:00:05, output 00:00:05, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 38021 packets input, 5656110 bytes, 0 no buffer Received 23488 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 38097 packets output, 2135697 bytes, 0 underruns 0 output errors, 0 collisions, 6045 interface resets 0 output buffer failures, 0 output buffers swapped out 482 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

53

Verifying PPP Authentication with the debug ppp authentication

Command

•4d20h: %LINK-3-UPDOWN: Interface Serial0, changed state to up•4d20h: Se0 PPP: Treating connection as a dedicated line•4d20h: Se0 PPP: Phase is AUTHENTICATING, by both•4d20h: Se0 CHAP: O CHALLENGE id 2 len 28 from ”left"•4d20h: Se0 CHAP: I CHALLENGE id 3 len 28 from ”right"•4d20h: Se0 CHAP: O RESPONSE id 3 len 28 from ”left"•4d20h: Se0 CHAP: I RESPONSE id 2 len 28 from ”right"•4d20h: Se0 CHAP: O SUCCESS id 2 len 4•4d20h: Se0 CHAP: I SUCCESS id 3 len 4•4d20h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up

•4d20h: %LINK-3-UPDOWN: Interface Serial0, changed state to up•4d20h: Se0 PPP: Treating connection as a dedicated line•4d20h: Se0 PPP: Phase is AUTHENTICATING, by both•4d20h: Se0 CHAP: O CHALLENGE id 2 len 28 from ”left"•4d20h: Se0 CHAP: I CHALLENGE id 3 len 28 from ”right"•4d20h: Se0 CHAP: O RESPONSE id 3 len 28 from ”left"•4d20h: Se0 CHAP: I RESPONSE id 2 len 28 from ”right"•4d20h: Se0 CHAP: O SUCCESS id 2 len 4•4d20h: Se0 CHAP: I SUCCESS id 3 len 4•4d20h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up

debug ppp authentication successful CHAP output

R1 R2Service Provider

debug ppp authentication

54

What is ISDN?

Providernetwork

Digital PBX

Small office

Home office

Voice, data, video

Telecommuter

Central site

55

Why ISDN?

ISDN - Integrated Services Digital Network

Telephone services -> Telecommunication services

Used for voice, data and video

56

� BRI and PRI are used globally for ISDN

Channel Mostly Used for

B Circuit-switched data (HDLC, PPP)

Capacity

64 kbps

D 2B

ISDN Access Options

Signaling informationD 16/64 kbps

23 or 30B

BRI

PRI

D

58

Interfaces and Devices

TE1

TE2 TA

NT12W4W

ISDN ReadyBRI Port

Analog devices:phone, Serial port

After connecting to TA it becomes TE1

S/T interface

U interface

ISDN Switch

59

Interfaces and Devices

Function Group – A set of functions implemented by a device or softwareReference Point – The interface between two function group

60

Reference Points

61

LAB-ISDN

E0

192.168.0.2 192.168.1.2

R2ISDN Switch

BRI

192.168.1.1

R1

E0BRI

192.168.0.110.0.0.1 10.0.0.2

Router(config)#hostname R1R1(config)#username R2 password ciscoR1(config-if)#int bri 0 R1(config-if)# ip address 10.0.0.1 255.0.0.0R1(config-if)#enacapsulation pppR1(config-if)#PPP authentication CHAPR1(config-if)#no shutStatic Routes or default routeR1(config)#ip route 0.0.0.0 0.0.0.0 10.0.0.2R1(config)#isdn switch-type basic-net3

Access ListR1(config)#dialer-list 1 protocol ip permitR1(config)#int bri 0R1(config-if)# dialer–group 1 R1(config-if)#dialer map ip 10.0.0.2 name R2 20R1(config-if)#no shutR1(config-if)#dialer idle-timeout 100

62

ISDN DDR configuration Commands

Command Description

iproute Global command that configure static route or default route

username name name password secret

Global command that configure CHAP username and password

access-list Global command that creates ACL’s to define a subset of traffic as interesting

dialer-list 1 protocol IP Global command that creates a dialer list that makes all IP traffic interesting or reference to ACL for subset

dialer–group 1 Interface subcommand that references dialer list to define what is interesting

dialer idle-timeout 100 Interface subcommand that settles idle time out values

dialer string number Interface subcommand that define dial numbers

int bri 0 Global command that selects BRI interface

63

Packet Switched Services

X.25 (Connection-oriented) Reliable--X.25 has been extensively debugged and is now very stable--

literally no errors in modern X.25 networks Store & Forward--Since X.25 stores the whole frame to error check it

before forwarding it on to the destination, it has an inherent delay (unlike Frame Relay) and requires large, expensive memory buffering capabilities.

Frame Relay (Connectionless) More efficient and much faster than X.25 Used mostly to forward LAN IP packets

64

Frame Relay Basics

• FR is WAN layer2 protocol• FR developed in 1984, its a faster

packet switching technology• In 1990 FR consortium was

developed and extension added

65

Terminology

Frame Relay Network

R2R1

End Device Interface DeviceEncapsulate Data

FR Network

DCE – Dedicated FR Switches, can be one or multiple

Access Line Trunk Line

Virtual Circuit – an end to end connection between interface device - PVC or SVC Data Link connection Identifiers (DLCI) number is the identification for VC, 16-1007 Committed Information Rate or CIR - agreed-upon bandwidth Frame Relay there are two encapsulation types: Cisco and IETF Local Management Interface (LMI) is a signaling standard used between your router

and the first Frame Relay switch i - Cisco, ANSI, and Q.933A.

67

LAB - Frame Relay

192.168.1.2/24 192.168.2.2/24

R2FR Switch

S0

192.168.2.1/24

R1

E0S0

192.168.1.1/24192.168.3.9/29

E0100 200

192.168.3.10/29

DCE DCE

Frame Relay SwitchRouter#config tRouter(config)#hostname FRSwitchFRSwitch(config)# frame-relay switchingFRSwitch(config)# int s 1/0FRSwitch(config-if)#enacapsulation frame-relayFRSwitch(config-if)# frame-relay intf-type DCEFRSwitch(config-if)# clock rate 64000FRSwitch(config-if)# frame-relay route 100 int serial 1/1 200FRSwitch(config-if)#no shut

R1Router#config tRouter(config)#hostname R1R1(config)# int s 0R1(config-if)#ip address 192.168.3.9 255.255.255.248R1(config-if)#enacapsulation frame-relayR1(config-if)# frame-relay intf-type DTER1(config-if)# frame-relay interface-dlci 100 R1(config-if-dlci)# exit R1(config-if)#framerelay map ip 192.168.3.10 100R1(config-if)#no shut