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Department of Information Technology

Chapter 2: Basic Router Configuration

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Presenter: Dr. Patrick D. CernaAsst. Professor

ITEC588 – Network Device Configuration

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Chapter 2 Objectives

• Connecting to a Cisco Router• Command Line Interface (CLI)• Administrative functions

– Hostnames– Banners– Passwords– Interface descriptions

• Verifying your configuration

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Router Access (Connecting to a Cisco Router - 173)

• Console port (console)– Rollover cable (each end is a mirror-image o/t other)• RJ-45 to DB-9• RJ-45 to DB-25

• Auxiliary port (AUX)– Can function like a console port– Or, can accept modem commands, i.e., from sources

outside the network (i.e., “out of band”)• Virtual terminal (VTY)– This is for telnet access– This kind of access is from within the network (i.e., “in

band”.

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Connecting To A Cisco Router

Cisco 2811

Cisco 1841

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Setup Mode

• Basic Management Setup• Extended Setup• Command-Line Interface

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Command-Line Interface (CLI)

• More flexible than setup mode.• To use the CLI, just say “No” to entering the initial

configuration dialog.• Initial prompt consists of two parts– Hostname– Greater than symbol (>)

p. 179

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Overview of Router Modes• Global changes:– config terminal or config t– Changes made to running-config (DRAM)– To change the startup-config (NVRAM)• config memory or config mem

• Note: Any configuration changes need to be placed into RAM.

• Typing “config mem” or “config net” (from a TFTP host) will append the current running-config

p. 1

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Configuration Modes• Global configuration mode– Router(config)#

• Interface mode– Router(config–if)#

• Line configuration mode– Router(config-line)#

• Router configuration mode– Router(config-router)#

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Configuration Modes

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Configuration

• CLI Prompts• Interfaces• Sub-interfaces• Line Commands• Routing Protocol

Configurations

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Administrative Functions

The administrative functions that you can configure on a router and switch are

• Hostnames• Banners• Passwords• Interface descriptions

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Hostnames & Descriptions• Hostnames

Router(config)#hostname haramayatodd(config)#

• DescriptionsAtlanta(config)#int e0Atlanta(config-if)#description cci_lan

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Banners• Purpose: welcome message• Types– exec: set EXEC process creation banner– incoming: set incoming terminal line banner– login: login banner– motd: set “Message of the Day” banner

• Delimiting character

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Banners

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Setting the Passwords• 5 passwords:– 1st two used to set your enable password

• Used to secure privileged mode; • Router>enable• Or Router>en (because no other commands at privileged

level . begin with “en”

– Other three are used to configure a password in user mode via:• console port• auxiliary port• Telnet

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Passwords• Enable passwords– Router(config)#enable password cisco– Router(config)#enable secret cisco

Note: the secret password supersedes the enable password, i.e., if you set both passwords, you will be asked for the secret password.

• Auxiliary Password• Console Password• Telnet Password• Encrypting Your Password

Router(config)#service password-encryption

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Passwords

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Passwords

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Passwords

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Passwords

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Passwords

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Interface DescriptionsSetting descriptions on an interface is helpful to the administrator and, like the hostname, only locally significant. The description command is a helpful one because you can, for instance, use it to keep track of circuit numbers.

Here’s an example:Atlanta(config)#int e0Atlanta(config-if)#description Sales LanAtlanta(config-if)#int s0Atlanta(config-if)#desc Wan to Miami circuit:6fdda4321

You can view the description of an interface either with the show running-config command or the show interface command.

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Router Interfaces

• Bringing up an Interfaceno shutdownshutdownshow interface

• Configuring an IP Address on an InterfaceRouter(config)#int e0Router(config-if)#ip address 172.16.10.2 255.255.255.0Router(config-if)#no shut

• Serial Interface Commandsclock rate & bandwidth (entered in kilobits)

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Viewing, & Saving Configurations

• Viewing & Saving Configurations– running-config saved in DRAM– startup-config saved in NVRAM

copy run startsh runsh starterase startup-config

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References:• Glen E. Clarke, CompTIA Network+, 4th ed.,

2009 Mc Graw Hill • CCNA Exploration, 2006, Cisco Press • Todd Lammle, CCNA Study Guide, 7th Ed.,

2009, Sybex

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