Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide

OL-5332-01

Chapter 1

Basic Router Configuration

Configuring Basic Parameters

For complete information about the command line commands, see the Cisco IOS Release 12.3

documentation set.

Step 3

login

Example:

Router(config)#

login

Router(config)#

Enables password checking at terminal session

login.

Step 4

exec-timeout

minutes

[

seconds

]

Example:

Router(config)#

exec-timeout 5 30

Router(config)#

Sets the interval that the EXEC command

interpreter waits until user input is detected. The

default is 10 minutes. Optionally, add seconds to

the interval value.

This example shows a timeout of 5 minutes and

30 seconds. Entering a timeout of 0 0 specifies

never to time out.

Step 5

line

[

aux

|

console

|

tty

|

vty

]

line-number

Example:

Router(config)#

line vty 0 4

Router(config)#

Specifies a virtual terminal for remote console

access.

Step 6

password

password

Example:

Router(config)#

password aldf2ad1

Router(config)#

Specifies a unique password for the virtual

terminal line.

Step 7

login

Example:

Router(config)#

login

Router(config)#

Enables password checking at the virtual terminal

session login.

Step 8

end

Example:

Router(config)#

end

Router#

Exits line configuration mode, and returns to

privileged EXEC mode.

Command

Purpose

Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide

OL-5332-01

Chapter 1

Basic Router Configuration

Configuring Static Routes

Configuration Example

The following configuration shows the command-line access commands.

You do not need to input the commands marked “default.” These commands appear automatically in the

configuration file generated when you use the

show running-config

command.

!

line con 0

exec-timeout 10 0

password 4youreyesonly

login

transport input none

(default)

stopbits 1

(default)

line vty 0 4

password secret

login

!

Configuring Static Routes

Static routes provide fixed routing paths through the network. They are manually configured on the

router. If the network topology changes, the static route must be updated with a new route. Static routes

are private routes unless they are redistributed by a routing protocol. Configuring static routes on the

Cisco 850 and Cisco 870 series routers is optional.

Perform these steps to configure static routes, beginning in global configuration mode:

Command

Purpose

Step 1

ip route

prefix mask

{

ip-address

|

interface-type

interface-number

[

ip-address

]}

Example:

Router(config)#

ip route 192.168.1.0

255.255.0.0 10.10.10.2

Router(config)#

Specifies the static route for the IP packets.

For details about this command and additional

parameters that can be set, see the

Cisco IOS IP

Command Reference, Volume 2 of 4: Routing

Protocols

.

Step 2

end

Example:

Router(config)#

end

Router#

Exits router configuration mode, and enters

privileged EXEC mode.

For complete information on the static routing commands, see the Cisco IOS Release 12.3

documentation set. For more general information on static routing, see

Appendix B, “Concepts.”

Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide

OL-5332-01

Chapter 1

Basic Router Configuration

Configuring Dynamic Routes

Configuration Example

In the following configuration example, the static route sends out all IP packets with a destination IP

address of 192.168.1.0 and a subnet mask of 255.255.255.0 on the Fast Ethernet interface to another

device with an IP address of 10.10.10.2. Specifically, the packets are sent to the configured PVC.

You do not need to enter the commands marked “(

default

).” These commands appear automatically in

the configuration file generated when you use the

show running-config

command.

!

ip classless (

default

)

ip route 192.168.1.0 255.255.255.0 10.10.10.2!

Verifying Your Configuration

To verify that you have properly configured static routing, enter the

show ip route

command and look

for static routes signified by the “S.”

You should see verification output similar to the following example.

Router#

show ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

10.0.0.0/24 is subnetted, 1 subnets

C

10.108.1.0 is directly connected, Loopback0

S* 0.0.0.0/0 is directly connected, FastEthernet0

Configuring Dynamic Routes

In dynamic routing, the network protocol adjusts the path automatically, based on network traffic or

topology. Changes in dynamic routes are shared with other routers in the network.

The Cisco routers can use IP routing protocols, such as Routing Information Protocol (RIP) or Enhanced

Interior Gateway Routing Protocol (EIGRP), to learn routes dynamically. You can configure either of

these routing protocols on your router.

Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide

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Chapter 1

Basic Router Configuration

Configuring Dynamic Routes

Configuring RIP

Perform these steps to configure the RIP routing protocol on the router, beginning in global

configuration mode:

Command

Task

Step 1

router rip

Example:

Router>

configure terminal

Router(config)#

router rip

Router(config-router)#

Enters router configuration mode, and enables RIP

on the router.

Step 2

version

{

1

|

2

}

Example:

Router(config-router)#

version 2

Router(config-router)#

Specifies use of RIP version 1 or 2.

Step 3

network

ip-address

Example:

Router(config-router)#

network 192.168.1.1

Router(config-router)#

network 10.10.7.1

Router(config-router)#

Specifies a list of networks on which RIP is to be

applied, using the address of the network of

directly connected networks.

Step 4

no auto-summary

Example:

Router(config-router)#

no auto-summary

Router(config-router)#

Disables automatic summarization of subnet routes

into network-level routes. This allows subprefix

routing information to pass across classful network

boundaries.

Step 5

end

Example:

Router(config-router)#

end

Router#

Exits router configuration mode, and enters

privileged EXEC mode.

For complete information on the dynamic routing commands, see the Cisco IOS Release 12.3

documentation set. For more general information on RIP, see

Appendix B, “Concepts.”

Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide

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Chapter 1

Basic Router Configuration

Configuring Enhanced IGRP

Configuration Example

The following configuration example shows RIP version 2 enabled in IP network 10.0.0.0 and

192.168.1.0.

Execute the

show running-config

command from privileged EXEC mode to see this configuration.

!

router rip

version 2

network 10.0.0.0

network 192.168.1.0

no auto-summary

!

Verifying Your Configuration

To verify that you have properly configured RIP, enter the

show ip route

command and look for RIP

routes signified by “R.” You should see a verification output like the example shown below.

Router#

show ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

10.0.0.0/24 is subnetted, 1 subnets

C

10.108.1.0 is directly connected, Loopback0

R

3.0.0.0/8 [120/1] via 2.2.2.1, 00:00:02, Ethernet0/0

Configuring Enhanced IGRP

Perform these steps to configure Enhanced IGRP (EIGRP), beginning in global configuration mode:

Command

Purpose

Step 1

router eigrp

as-number

Example:

Router(config)#

router eigrp 109

Router(config)#

Enters router configuration mode, and enables

EIGRP on the router. The autonomous-system

number identifies the route to other EIGRP routers

and is used to tag the EIGRP information.