Configuring a Router CCNA 2 v 3 Module

Configuring a Router CCNA 2 v 3 – Module 3 NESCOT CATC 1

CLI Command Modes User EXEC Privileged EXEC Global Configuration Specific Modes NESCOT CATC 2

Configuring a Routers should be given a unique names as one of the first configuration tasks: Router(config)# hostname Tokyo(config)# _ Passwords should be configured for vty lines, the console and to control access to privileged EXEC mode: Router(config)# enable secret class Router(config)# line con 0 Router(config-line)# password cisco Router(config-line)# login To avoid passwords being shown in clear text in the output from the show running-config or show startup-config commands: Router(config)# service password-encryption NESCOT CATC 3

Show commands Command show interfaces show int s 0/1 Displays all the statistics for all the interfaces on the routerfor a specific interface (serial 0/1) Statistics show controllers s 0/1 Displays information-specific to the interface hardware show clock Shows the time set in the router show hosts show users show history show flash show version show arp show protocol Displays a cached list of host names and addresses Displays all users who are connected to the router Displays a history of commands that have been entered Information about flash memory and IOS files stored thereabout the router and the IOS running Information in RAM the ARP table of the router Displays show startup-config Global and interface specific status of Layer 3 protocols The saved configuration located in NVRAM show running-config Displays configuration currently running in RAM NESCOT CATC 4

Configuring Serial Interfaces 1. Enter interface mode: Router(config)# interface serial 0/1 2. Specify the interface address and subnet mask: Router(config-if)# ip address 192. 168. 1. 1 255. 0 3. Set clock rate if a DCE cable is connected (skip this step if a DTE cable is connected): Router(config-if)# clock rate 56000 Serial interfaces require a clock signal to control the timing of the communications. DCE devices provide the clock. By default, Cisco routers are DTE devices but they can be configured as DCE devices. 4. Turn on the interface Router(config-if)# no shutdown Router(config-if)# exit Router(config)# _ NESCOT CATC 5

Changing and Saving the Configuration Make changes in configuration mode Examine results: Router# show runningconfig Intende d results? Yes No Save changes to backup: Router# copy run start Router# copy runningconfig tftp Examine backup file: Router# show startup-config Remove changes Router(config)# no… Router# copy running start Router# copy tftp runningconfig Router# erase startup-config Router# reload NESCOT CATC 6

Interface Descriptions Interface descriptions can be used to identify information such as: n distant router n a circuit number n specific network segment Router(config)# interface ethernet 0 Router(config-if)# description Room C 379 LAN Banner MOTD Message-of-the-Day banner can be displayed on all connected terminals: Router(config)# banner motd # Enter TEXT message. BEGIN and END with a character #. #ACME Computer Network – Restricted Access # Router(config)#_ A login banner should be a warning not to attempt login unless authorized. NESCOT CATC 7

Host Name Configuration Host name resolution associates a host name with an IP address. These address mappings are stored in a host table. Host names, unlike DNS names, are significant only on the router on which they are configured. A host table allows you to type either the host name or the IP address to Telnet or Ping to a remote host. London(config)# ip host London 200 London(config)# ip host New. York 10. 0. 0. 1 London(config)# ip host Paris 192. 168. 1. 1 London(config)# ip host Munich 172. 16. 0. 1 London(config)# end London# show hosts Default domain is not set Name/address lookup uses domain services Name servers are Host London New. York Paris Munich Flags (perm, OK) OK) Age Type ** IP NESCOT CATC Address(es) 200 10. 0. 0. 1 192. 168. 1. 1 172. 16. 0. 1 8

Configuration Backup and Documentation The configuration of network devices determines how the network will behave. Management of device configuration includes the following tasks: u u u Listing and comparing configuration files on running devices Storage of configuration files on network servers Performing software installations and upgrades Configuration files should be stored as backup files in the event of a problem. Documentation should be included with this offline information. Configuration files can be stored on a network server, on a TFTP server, or on a disk stored in a safe place. NESCOT CATC 9

Copying, Editing, and Pasting Configurations To store the current configuration on a network TFTP server enter the following command: My# copy running-config tftp Remote host []? 131. 108. 2. 155 Name of configuration file to write[my-config]? My 2 Write file My 2 to 131. 108. 2. 155 ? [confirm] y Writing My 2 !!!!!!!!!! [OK] A configuration file stored on one of the network servers can be used to configure a router: Router# copy tftp running-config Host or network configuration file [host]? IP address of remote host[255. 255]? 10. 0. 0. 13 Name of configuration file [Router-config] ? My 2 Configure using My 2 from 10. 0. 0. 13? [confirm] y Booting My 2 from 10. 0. 0. 13: !!!!!! [OK-180/16000 bytes] NESCOT CATC 10