Configuring a RouterConfiguring a RouterConfiguring a RouterConfiguring a Router

Harold Hernandez, MS, CCNIHarold Hernandez, MS, CCNI

3.1 Configuring a Router

• Name a router • Set passwords • Examine show commands • Configure a serial interface • Configure an Ethernet interface • Execute changes to a router • Save changes to a router

CLI Command Modes

Configuration Modes

Let’s PlayLet’s PlayLet’s PlayLet’s Play

What does it do?What does it do?

Changes the name of the router

• Router(config)#hostname Tokyo

Identifies the console port for configuration.

• Router(config)#line console 0

Tells the router to prompt the user for a password

• Router(config-line)#login

Sets the password to access the line as cisco• Router(config-line)#password

cisco

Identifies telnet sessions 0 to 4 for configuration.

• Router(config)#line vty 0 4

Restricts access to privilaged exec to those who know the password

• Router(config)#enable password class

Restricts access to priv. exec and doesn’t show password in clear text

when displaying running-config

• Router(config)#enable secret class

Encrypts all passwords so they aren’t in clear

text.• Router(config)#service

password-encryption

Gives info about s0/1 including DCE/DTE end of

serial cable

• Router#show controllers serial 0/1

Displays config stored in NVRAM

• show startup-config

Displays configuration in RAM

• show running-config

Specifies interface to be configured.

• Router(config)#interface serial 0/0

Attaches an IP address to an interface

• Router(config-if)#ip address <ip address > <netmask >

Establishes a timing mechanism for lab

routers• Router(config-if)#clock rate

56000 How do you know which router should use this command?

It’s the router with the DCE cable attached to its serial port!

Brings an interface back up after it’s been

configured.• Router(config-if)#no shutdown

Removes configuration from NVRAM.

• erase startup-config

Copies configuration from RAM to NVRAM

• Router#copy running-config startup-config

3.2 Finishing the Configuration

• Configure an interface description • Configure a message-of-the-day

banner • Configure host tables • Understand the importance of

backups and documentation

Documentation• The _________ command allows

administrators to add comments about a particular interface.

• Login banners can be used to convey messages that affect all network users, such as scheduled system shutdowns.

• banner motd # <message of the day > # sends a message to any attached terminal.

description

Ease of Use• _________ are short-cuts that aid

administrators when testing routes. • By assigning an IP address a name, the

admin can ping the name instead of the 32-bit dotted decimal IP address.

• IP host BW 192.168.1.1 is an example of one such short-cut.

Host tables

Life is beautiful