Cisco Router Configuration CLI Modes

After reading this article you can learn the different Router CLI configuration modes and their specifications. I described CLI Modes in hierarchical structure. Any Network administrator must have to learn these modes initially. It is useful to configure and troubleshoot any Cisco Routers and Switches.  This is also help you to passing your Cisco certification exams. Generally the lower end Routers uses different commands than the mid to upper range routers. The commands we are using on different Cisco Devices are almost the same, but there are always a few variations to these commands depending on the interfaces your Cisco Devices has, IOS version, and the type of WAN protocols they support. You can get CLI access by using console port or remote access protocols like telnet or SSH.

To enable security feature, Cisco IOS separates EXEC sessions into two different access levels  are user EXEC level and privileged EXEC level. User EXEC level allows a person to access only a limited amount of basic monitoring commands. Privileged EXEC level allows a person to access all router commands (e.g. configuration and management) and can be password protected to allow only authorized users the ability to configure or maintain the router.

Cisco IOS CLI Configuration Modes

List of Cisco Router Command Line Interface (CLI) Modes

S.No

Cisco Router

CLI Configuration modes

1 Router-CLI> User Mode
2 Router-CLI# Privileged mode or  EXEC-level mode
3 Router-CLI(config)# Global configuration mode
4 Router-CLI(config-if)# Interface Configuration mode
5 Router-CLI(config-subif)# Sub Interface Configuration mode
6 Router-CLI(config-line)# Line Configuration mode
7 Router-CLI(config-router)# Router configuration mode

User Exec Mode:

This is the first mode you’ll see on a Cisco Router is user exec mode. This is also the default one when you are connected the Router using Telnet. You can’t write or add to a configuration in this mode, but you can run quite a few show commands. This is a good mode to have users in who need to see the configuration, but shouldn’t be allowed to change it.

Router>

Privilege or Enable Mode:

This mode has two names, the official one being privileged exec mode. It’s more commonly referred to as enable mode, since “enable” is what you type to get into this mode. Now you got complete access privileges of Cisco device but this mode gives you more options for show and other commands, but you still can’t configure anything.

Router>enable
Router#

Setup Mode:

Router will go to the setup mode if it is brand new or with default condition. After completing the booting process, It will prompt in setup mode for initial configuration dialogue if there is no configuration in the memory. Already configured Router will not prompt setup mode directly. You can also enter into the setup mode any time by using setup command.

Router # setup
System Configuration Dialog Continue with configuration dialog? [Yes/no]: Y
At any point you may enter a question mark “?” for help
Use ctrl-c to abort the configuration dialog at any prompt
Default settings are in square brackets “[ ]”
Basic management setup configures only enough connectivity for management of the Router, extended setup will ask you to configure each interface on the Router.
Would you like to enter basic management setup? [Yes/no] n

Global Configuration Mode:

To configure the Cisco Router, you must have to enter the global configuration mode. To enter into this mode, issue the configure terminal or config t command from the privileged EXEC mode. All the configurations are done in this mode, and you can also issue a show command like in privilege exec mode by using Do command.

Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#

Interface Configuration Mode:

To configure any interface, you have to enter the interface’s  mode. To enter into this mode, issue the interface command from the global configuration mode. You can go back to the privileged EXEC mode by pressing CTRL+Z or issue an END command. To exit from this mode, issue the EXIT command, and you’ll be moved to the global mode. You can also use show commands with DO command here.

Router(config)#interface serial0
Router(config-if)#

Sub Interface Configuration Mode:

To configure any logical interfaces on Cisco Router, you have to enter the sub interface’s  mode. To enter into this, issue the interface command from the global mode with sub or logical interface number.

Router(config)#interface FastEthernet 0/0.1
Router(config-subif)#

Router Configuration Mode:

To configure a Router protocol, you have to enter a specific Routing protocol command in global mode. If want to execute a privileged EXEC commands such as the show command, you can execute using DO command. You can go back to the privileged EXEC mode by pressing CTRL+Z or with END command. To exit from this mode, issue the exit command.

Routers(config)#router rip
Routers(config-router)#exit
Routers(config)#

Line Configuration Mode:

To configure authentication to access the router using the console port or remotely, you have to enter the configuration mode of the specific line(s). To enter into this, issue the line command from the global mode or other configuration mode. If you wish to execute a privileged EXEC command such as the show command, you can precede it by the DO command. You can go back to the privileged EXEC mode by pressing CTRL+Z or with END command. To exit from this mode, issue the exit command.

Cisco-Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Cisco-Router(config)#line console 0
Cisco-Router(config-line)#password cisco
Cisco-Router(config-line)#login
Cisco-Router(config-line)#line vty 0 4
Cisco-Router(config-line)#password cisco
Cisco-Router(config-line)#login

Notice that you do not have to exit one interface mode to go to another one. Let’s say that you’ve configured your VTY lines and now want to put an IP address on your Ethernet interface. You don’t have to go out with ctrl-z and then start again – you can go straight to interface config mode from line config mode. Just make sure you see the prompt change.

 

Filed Under: Cisco General

Tags:

About the Author:

RSSComments (1)

Leave a Reply | Trackback URL

  1. Lee says:

    Thanks a million for this, I appreciate the info

Leave a Reply




If you want a picture to show with your comment, go get a Gravatar.