1 CCNA 2 v3.1 Module 3

2 CCNA 2 Module 3 Configuring a Router

333 Overview

444 To go back a level Type exit To return to privileged EXEC mode Press Ctrl-Z To execute a command Press Enter/Return

555 Configuring a Router Name You must be at Global configuration mode Commands Enter Privilaged exec mode Router>enable Enter global configuration mode Router#Configure terminal Enter hostname Router(config)#hostname Tokyo Return to configuration mode Tokyo(config)# exit Tokyo#

666 Configuring router passwords Passwords ensure that only authorized users may make changes to the configuration file Passwords restrict access to routers through virtual terminal lines (telnet connection) console line to privileged EXEC mode

777 Console Password Enter console line Router(config)#line console 0 Enter the password Router(config-line)#password Force password to be activated at login Router(config-line)#login Telnet Password Router(config)#line vty 0 4 Router(config-line)#password Router(config-line)#login Cisco Routers support 5 lines (0 – 4)

888 To restrict access to Privileged EXEC mode Enable password Only used when enable secret not set Not encrypted Router(config)#enable password Enable secret password Takes precedence over enable password Encrypted Router(config)#enable secret

999 Encrypting Configuration File Passwords To prevent passwords shown in clear text To encrypt passwords in configuration output that maybe exposed by “Show” command Router(config)#service password-encryption This uses an encryption algorithm called MD5 Note: not needed if you use “enable secret”. To turn this option off Router(config)#no service password-encryption

10 Show commands To display all show commands Router# Show ? Router#show interfaces Displays statistics for all router interfaces Router#show interfaces serial 0/1 Displays statistics for serial 0/1 interface only Router#show controllers serial Displays information-specific to the interface hardware

11 Router#show clock Shows the time set in the router Router#show hosts Displays a cached list of host names and addresses Router#show users Displays all users who are connected to the router Router#show history Displays a history of commands that were entered Router#show flash Displays information about flash memory Displays what IOS files are stored there

12 Router#show version Displays information about the router Displays the IOS that is running in RAM Router#show ARP – Displays the ARP table of the router Router#show protocol Displays status of any configured Layer 3 protocols Router#show startup-configuration Displays the saved configuration in NVRAM Router#show running-configuration Displays the configuration currently running in RAM

13 Configuring Serial and Ethernet Ports Both can be configured from Console port Through a virtual terminal line (telnet)

14 Configuring a Serial interface 1.Enter global configuration mode Router#config t 2.Enter interface mode Router(config)#int s0/0 3.Specify the interface ip address and subnet mask Router(config-if)#ip address 4.If DCE cable set clock rate and bandwidth (not DTE) Router(config-if)#clock rate Router(config-if)#bandwidth 64 5.Turn on the interface Router(config-if)#no shutdown

15 Configuring an Ethernet Interface 1.Enter global configuration mode Router# configure terminal 2.Enter interface configuration mode Router(config)#interface fast ethernet 0/0 3.Specify the interface address and subnet mask Router(config-if)#ip address 4.Enable the interface Router(config-if)#no shutdown

16 Saving Configuration Changes Save changes from RAM to NVRAM Router#copy running-config startup-config Save changes from RAM to TFTP server Router#copy running-config tftp Examining Configuration Files Examine running configuration in RAM Router#show running-config Examine startup configuration in NVRAM Router#show start

17 To Make Changes Use the word NO To turn off the ip address and subnet mask Router(config-if)#no ip address To turn off the bandwidth Router(config-if)#no bandwitdh To turn off the clock rate Router(config-if)#no clockrate When changes are made Router(config-if)#no shut

18 To turn on or enable an interface Router(config-if)#no shutdown To turn off or disable an interface Router(config-if)#shutdown Copy from RAM to TFTP server Router#copy running-config tftp Restore from TFTP to RAM Router#copy tftp running-config

19 Force router to use the original configuration file in NVRAM Router#copy startup-config running-config Force router to use the configuration file on the tftp server Router#copy tftp running-config Erase the startup configuration file from NVRAM Router#write erase OR-Router#erase start Router#reload-Router#reload

20 Execute adds, moves, changes

21 Interface Descriptions Description is a comment about the interface The description may include Purpose of the interface Location of the interface Devices or locations connected to the interface How to set up the interface description Enter global configuration mode Router#configure terminal Enter the specific interface you wish to describe Router(config)#int e0 Specify description Router(config-if)#description Itsligo LAN, RM D2001

22 Login Banners Displayed at login Conveying messages that affect all network users E.g., Notices of impending system shutdowns. How to set up a login banner Enter global configuration mode Router#configure terminal Enter the login banner Router(config)#banner motd # message # Save/backup changes to NVRAM Router(config)#exit Router#copy run start

23 Host name resolution Associate a host name with an IP address Host Table list of host names and associated IP addresses Host names are only significant on the router on which they are configured Steps to configure host names Router(config)#ip host Lab_A Router(config)#ip host Lab_B

24 To view all hosts Router#show hosts To ping a host Router#ping Lab_A OR Router#ping To telnet into a host Router#telnet Lab_A OR Router#telent

25 Configuration Backup and Documentation Management of device configuration includes Listing and comparing configuration files on running devices Storage of configuration files on network servers Performing software installations and upgrades Configuration files can be stored on a Network server TFTP server Disk stored in a safe place