A router is a layer 3 device used to forward packet from one network to another. It forwards the packet through one of its port on the basis of destination IP address and the entry in the routing table. By using routing table, it finds an optimised path between the source and destination network.
Let’s discuss about about Cisco router different modes.
Modes of router –
There are mainly 5 modes in router:
- User execution mode –
As soon as the interface up message appears and press enter, the router> prompt will pop up. This is called user execution mode. This mode is limited to some monitoring commands.
- Privileged mode –
As we type enable to user mode, we enter into Privileged mode where we can view and change the configuration of router. Different commands like show running-configuration, show IP interface brief etc can run on this mode which are used for troubleshooting purpose.
- Global configuration mode –
As we type configure terminal to the user mode, we will enter into the global configuration mode. Commands enter in these modes are called global commands and they affect the running-configuration of the router. In this mode, different configuration like making local database on router by providing username and password, can set enable and secret password etc.
- Interface configuration mode –
In this mode, only configuration of interfaces are done. Assigning an IP address to an interface, bringing up the interface are the common tasks done in this mode.
- ROMMON mode –
We can enter in this mode when we interrupt boot process of the router. Generally, we enter in this mode while password recovery process or Backing up of IOS on device like TFTP server. It is like BIOS mode of a PC.
Entering and exiting in different modes:
|Modes||Access method||prompt||Exit method|
|user execution mode||login||router>||use logout commnad|
|privilege mode||use enable command in user mode||router#||use disable command to enter user mode|
|global configuration mode||use configure terminal command||router(config)#||use exit command to enter into privilege mode|
|Interface mode||use interface command and specify an interface in global configuration mode||router(config-if)#||use exit command to enter into global configuration mode or use end command to enter into privilege mode.|
|ROMMON mode||press ctrl+break key while boot process or use reload command in privilege mode.||ROMMON 1>||use continue command|
The user execution mode:
Entering into privilege mode from user execution mode:
Exiting from privilege mode to user execution mode:
Entering in global configuration mode from privilege mode:
router#configure terminal router(config)#
Exiting from global configuration mode to privilege mode:
Entering into interface mode from global configuration mode.here we have to specify the router’s interface.
router(config)#interface fa0/0 router(config-if)#
Exiting from interface mode to global configuration mode.
Exiting from interface mode to privilege mode.
Entering into ROMMON mode from privilege mode.