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CCNA 2 Module 3 Configuring a Router

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Objectives

• Upon completion of this module, the student will be able to perform tasks related to the following:

• Configuring a router

• Finishing the configuration

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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

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Command-Line InterfaceCommand Modes

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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 TokyoTokyo(config)#

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Configuring Router Passwords

The service password-encryption command

applies a weak encryption to all

unencrypted passwords.

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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.

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Examining the show CommandsContinued

• 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

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Examining the show CommandsContinued

• 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

• show running-configuration – Displays the configuration currently running in RAM

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show version Command Example

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Serial Interface Configuration Commands

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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.

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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.

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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.

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Interface Description

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Login Banners

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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.

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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

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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.

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Configuring Host Tables

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Configuring Host TablesContinued

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Configuration Backup and Documentation

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Using the copy running-config tftp Command

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Using the copy tftp running-config Command

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Summary