1 © 2003, Cisco Systems, Inc. All rights reserved. CCNA 2 Module 3 Configuring a Router

222 © 2003, Cisco Systems, Inc. All rights reserved. Objectives Upon completion of this module, the student will be able to perform tasks related to the following: Configuring a router Finishing the configuration

333 © 2003, Cisco Systems, Inc. All rights reserved. Overview 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 Configure an interface description Configure a message-of-the-day banner Configure host tables Understand the importance of backups and documentation

444 © 2003, Cisco Systems, Inc. All rights reserved. Command-Line Interface Command Modes

555 © 2003, Cisco Systems, Inc. All rights reserved. Configuring a Router Name A router should be given a unique name as one of the first configuration tasks. This task is accomplished in global configuration mode using the following commands: Router(config)#hostname Tokyo Tokyo(config)#

666 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Router Passwords The service password- encryption command applies a weak encryption to all unencrypted passwords.

777 © 2003, Cisco Systems, Inc. All rights reserved. Examining the show Commands There are many show commands that you can use to examine the contents of files in the router and for troubleshooting. In both privileged EXEC and user EXEC modes, the command show ? provides a list of available show commands.

888 © 2003, Cisco Systems, Inc. All rights reserved. Examining the show Commands Continued show interfaces – Displays all the statistics for all the interfaces on the router show clock – Shows the time set in the router show hosts – Displays a cached list of host names and addresses show users – Displays all users who are connected to the router show history – Displays a history of commands that have been entered show flash – Displays information about flash memory and what IOS files are stored there

999 © 2003, Cisco Systems, Inc. All rights reserved. Examining the show Commands Continued show version – Displays information about the router and the IOS that is running in RAM show ARP – Displays the ARP table of the router show protocol – Displays the global and interface specific status of any configured Layer 3 protocols show startup-configuration – Displays the saved configuration located in NVRAM s how running-configuration – Displays the configuration currently running in RAM

10 © 2003, Cisco Systems, Inc. All rights reserved. show version Command Example

11 © 2003, Cisco Systems, Inc. All rights reserved. Serial Interface Configuration Commands

12 © 2003, Cisco Systems, Inc. All rights reserved. Configuring an Ethernet Interface To configure an Ethernet interface follow these steps: Enter global configuration mode. Enter interface configuration mode. Specify the interface address and subnet mask. Enable the interface.

13 © 2003, Cisco Systems, Inc. All rights reserved. Configuring an Serial Interface To configure an Ethernet interface follow these steps: Enter global configuration mode. Enter interface configuration mode. Specify the interface address and subnet mask. Set clock rate if a DCE cable is connected. Skip this step if a DTE cable is connected. Enable the interface.

14 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Interface Descriptions An interface description should be used to identify important information such as a distant router, a circuit number, or a specific network segment. A description of an interface can help a network user remember specific information about the interface, such as what network the interface services.

15 © 2003, Cisco Systems, Inc. All rights reserved. Interface Description

16 © 2003, Cisco Systems, Inc. All rights reserved. Login Banners

17 © 2003, Cisco Systems, Inc. All rights reserved. Login Banners (MOTD) A login banner is a message that is displayed at login. Login banners can be used to convey messages that affect all network users, such as scheduled system shutdowns. Login banners can be seen by anyone. “Welcome” is an invitation for anyone to enter a router and is probably not an appropriate message. A login banner should warn users not to attempt login unless they are authorized. A message such as “This is a secure system, authorized access only!” informs unwanted visitors that any further intrusion is illegal.

18 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Message-of-the-Day (MOTD) Enter global configuration mode to configure a message- of-the-day (MOTD) banner. Use the banner motd command, followed by a space and a delimiting character, such as the pound sign (#). Add a message-of-the-day (MOTD) followed by a space and the delimiting character again

19 © 2003, Cisco Systems, Inc. All rights reserved. Host Name Resolutions Host name resolution is the process that a computer system uses to associate a host name with an IP address. Host names, unlike DNS names, are significant only on the router on which they are configured.

20 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Host Tables

21 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Host Tables Continued

22 © 2003, Cisco Systems, Inc. All rights reserved. Configuration Backup and Documentation

23 © 2003, Cisco Systems, Inc. All rights reserved. Using the copy running-config tftp Command

24 © 2003, Cisco Systems, Inc. All rights reserved. Using the copy tftp running-config Command

25 © 2003, Cisco Systems, Inc. All rights reserved. Summary