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CCNA 2 v3. 1 Module 3. CCNA 2. Module 3 Configuring a Router. Overview. To go back a level Type exit To return to privileged EXEC mode Press Ctrl-Z To execute a command Press Enter/Return. Configuring a Router Name. You must be at Global configuration mode Commands
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CCNA 2 Module 3 Configuring a Router
To go back a level • Type exit • To return to privileged EXEC mode • Press Ctrl-Z • To execute a command • Press Enter/Return
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#
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
Console Password • Enter console line • Router(config)#line console 0 • Enter the password • Router(config-line)#password <password> • Force password to be activated at login • Router(config-line)#login • Telnet Password • Router(config)#line vty 0 4Router(config-line)#password <password>Router(config-line)#login • Cisco Routers support 5 lines (0 – 4)
To restrict access to Privileged EXEC mode • Enable password • Only used when enable secret not set • Not encrypted • Router(config)#enable password <password> • Enable secret password • Takes precedence over enable password • Encrypted • Router(config)#enable secret <password>
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
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
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
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
Configuring Serial and Ethernet Ports • Both can be configured from • Console port • Through a virtual terminal line (telnet)
Configuring a Serial interface • Enter global configuration mode • Router#config t • Enter interface mode • Router(config)#int s0/0 • Specify the interface ip address and subnet mask • Router(config-if)#ip address <ip address> <subnet mask> • If DCE cable set clock rate and bandwidth (not DTE) • Router(config-if)#clock rate 56000 • Router(config-if)#bandwidth 64 • Turn on the interface • Router(config-if)#no shutdown
Configuring an Ethernet Interface • Enter global configuration mode • Router# configure terminal • Enter interface configuration mode • Router(config)#interface fast ethernet 0/0 • Specify the interface address and subnet mask • Router(config-if)#ip address <ip address> <subnet mask> • Enable the interface • Router(config-if)#no shutdown
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
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
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
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
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
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
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 172.51.1.1 • Router(config)#ip host Lab_B 180.101.21.1
To view all hosts • Router#show hosts • To ping a host • Router#ping Lab_A • OR Router#ping 172.51.1.1 • To telnet into a host • Router#telnet Lab_A • OR Router#telent 172.51.1.1
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