Cisco Router Configuration

Router Configuration

Date                                          3/2/2010

Objective                                  Configure a new Cisco Router

Aim                                           Understand how to use the Cisco IOS command line interface (CLI) to        configure and manage a Cisco router.

Cisco Router

                   Cisco Router is a network hardware device which we can use to interconnect different networks to communicate with each other. It is running under Network Layer (layer 3) in OSI model and uses many protocols to communicate. Cisco Router contains several interfaces. They are,

Console and auxiliary-             used to configure the device.

Auxiliary -                                 used to configure the router from remote area via dial-up connection.

                        Router has its own operating system which is called as Internetwork operating system. And its main components are Ram, Rom, Flash, NV Ram, Interfaces and CPU.

Equipment List

Cisco router

Personal computer

PC and router arrangement

            We can also configure the when we connect with a LAN. Initially we can connect with Router & can configure.

Procedure:

Initially we will probably configure our router from a terminal. If the router is already configured and at least one port is configured with an IP address and it has a physical connection to the network. If it is not already configured, then you will have to directly connect to it with a terminal and a serial cable. Plug a serial cable into a serial (COM) port on the PC and the other end into the console port on the Cisco router. Start HyperTerminal, tell it which COM port to use and click OK. If the router is not on, turn it on. Then Run the Cisco IOS software. Using that Prompt we can configure the Router from giving following commands.

If the router is configured before.

First we can see,

Password:

After giving the password & press enter

cisco>?

 We can see name of the router as “Cisco”.

If the router is not configured before we can see,

Router>?

 User mode and privileged mode

User Mode (>) - 

When we first connect to the router and provide the password (if necessary), we enter User mode, the first mode in which we can issue commands from the command-line. From here we can use commands as ping, telnet, and rlogin. We can also use some of the show commands to obtain information about the system.

Privileged mode (#) –

We are used privileged mode to configure the router. Privileged mode will usually be password protected unless the router is not configured. We have the option of not password protecting privileged mode, but it is highly recommended that we do. When we issue the command enable and provide the password, you will enter privileged mode. Within privileged mode there are many sub-modes.

In user mode

cisco>show ?

Will display all the show commands available in the mode we are presently in.

  Ex -   ping             Send echo messages                                     

   ppp                          Start IETF Point-to-Point Protocol (PPP)                                                          

  resume                     Resume an active network connection                                                     

  rlogin                       Open an rlogin connection   

When we want to enter privileged use command-   enable

cisco>enable           Type “enable” & press enter         

Password:              Type password & press enter    

cisco#?              Entered to the privilege mode

# is the sing of the privilege mode. Now we are entered to the privilege mode. Now we can configure the router.

If we want to move back to the user mode uses “disable” command.

cicso>#disable

If wants to see commands in Privileged mode. -  show

cisco#show ?            Type “show” then leaves a space, type”?”  & presses enter.

 

access-expression List      access expression

access-lists                List access lists

adjacency                   Adjacent nodes

aliases                     Display alias commands

arp                         ARP table 

                                                                  

                             

          

These are the basic configurations in Cisco router configurations. But if you want more please stay touch with us. I will provide that later in another article.