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