If you’re new to computer Networks and into handling CISCO devices you may have come across the User EXEC Mode, Privileged mode and Configuration mode, these are various mode a CISCO router operates in.
There are 16 (0-15) privileged levels to access various command on the CISCO router, when you enter the User EXEC Mode, You’re at Privileged Level 1 and you move up to Level 15, directly, by typing in Enable command in the User EXEC mode.
In order to configure CISCO routers at various levels, you have to navigation between these mode and key in some commands.
So, you can access the router’s User EXEC mode on the router via
1. Console port
2. AUX port
3. Telnet – Telnetting into the router remotely.
User EXEC Mode
User can type in harmless EXEC commands, harmless, as it wont hurt the routers operations, and EXEC as the router takes the command executes its and give you an output.
When you are in the user mode you will see ‘>‘ at the command prompt
P.S.: IOS has a great inbuild help system, anytime you need help type in the ‘?’
Some of the commands may give you a long output, use the SPACEBAR to see the next paragraph on the screen and ENTER to see the next line on screen, any other key to terminate the command output.
There are no configurations done, this mode is just to view various configurations of the router.
Some of the commands include,
show ip interaces
show ip route
Tip: You can use ? to know the next option eg. if you type ‘show?’ it will show the the options available with show command
also, if you type in ‘show in’ and press the Tab key, if the code is unique, IOS will complete the word for you, in this case, in = interfaces as there is no other word after show, starting with in other than interfaces.
Enable Mode a.k.a Privileged EXEC mode
To move to the enable mode, the user has to type enable at the > prompt and hit Enter, the prompt changes to # indicating that you’re in the Enable mode, to get back to the User EXEC mode type disable and hit enter.
This mode allows users to VIEW all configurations on the router and allow to change some less important configuration, there are a few commands that work on both User EXEC and Enable mode, basically Enable mode is a high privileged User EXEC, with more power to use the router.
You can do various things, like changing the hostname of the router, adding password to this mode, see the running-configuration of the router and more, BUT, you can configure the router or get the root access to make changes to how the router operates in a network, for that you need to get into Global Configuration mode.
Global Configuration Mode
This is the root access, privileged level 15 mode, where you have the root access to the router, you can do the configuration, change the IOS version, backup, restore and more.
It looks like this:
Notice (config) before that # indicating that it is in Global Configuration mode.
To enter the Global configuration mode from the Enable mode you have to enter configure terminal in the Enable mode, to return back type End or Exit or press Ctrl+z
There are several submodes like:
- Interface Mode: It is used to configure details about a specific router interface, such as an IP address, it looks like this Router(config-if)#
To enter interface mode, type interface interfacename in the Global configuration mode, eg: Router(config)# interface serial 0/1/0 and then add various parameters to that interface
- Line Configuration Mode: Configure details about like (console, vty, AUX), looks like this Router(config-line)#
To enter the Line configuration mode, type line con 0 in the Global configuration Mode and then configure, a lot of things for Console, including Login and Password
- Router Configuration Mode: Configure details about routing protocols looks like this Router(config-router)#
To enter the Router configuration mode, type router protocol in the Global configuration mode and then configure various aspects.
We hope this clear out the various modes on a CISCO router and their functions and differences between them.
There are 2 more modes, that we will be covering in a separate post, as they have specialized function, Setup Mode and ROMMON mode
If you have any queries regarding this, feel free to comment below.
The DNetWorks Team