Router Configuration - Introduction

 

Router Configuration - Introduction:

There are mainly 3 Modes in Cisco Router

(1) User Execution Mode           :This mode is limited to some monitoring commands.

(2) Privilege Execution Mode    : Here we can save, see the configuration, troubleshoot, ping, tracert etc

(3) Global Configuration Mode  : Here we  configure any kind of configuration of  our router , set hostname etc

 There are some other modes also: 

To go to Privilege Execution Mode from User Execution Mode:

   Router> enable

To go to Global Configuration Mode from Privilege Execution Mode

   Router# configure   terminal

            or

   Router# conf  t

What we can do in Privilege Execution Mode:

For saving configuration:

Router # copy  running-config  startup-config   /   copy   runn   start    /  write  /wr

For showing:

Router #  show running-config   /  show runn  / sh runn     [To see configuration file]

Router #  show ip interface  brief                                          [To see IP information on Interfaces]

To test connectivity :

Router# ping  10.1.1.2     ; Here 10.1.1.2  is my target  ip

To reload/restart the device :

Router# reload

What we can in Global Configuration Mode:

To Set IP Configuration:

Router(config) # interface  fast-ethernet  0/0                /               int  f 0/0

Router(config-if) # ip   address  10.1.1.1  255.0.0.0      /                ip   add   10.1.1.1    255.0.0.0

Router(config-if) # no shutdown                                   /                no sh

 

To set hostname:

Router(config) # hostname  itbd

***To go to the previous mode

We will use "exit" command

If you are lazy as like me - you can use CTRL+c to go the 2nd mode(privilege execution mode)  from any mode

                     

In VPCs(GNS3), IP Configuration:

PC> ip  10.1.1.1/8  10.1.1.254     [To set IP, Subnet-Mask, Gateway - Here 10.1.1.254  is gateway]

PC> ip  dns  8.8.8.8                        [To set DNS IP]

PC> save                                         [To save your configuration]

PC> show ip                                   [To see IP information]

PC> ping  10.1.1.2                          [To test connectivity with other PC's IP]

PC> clear ip                                    [To reset/clear IP info]