Cisco: How Simple is the Cisco Command Line?

The Cisco Command Line interface is similar to that of our Windows’ command line or command prompt as we call it. It is in here that we input our commands to configure our devices on how to function. There is no Graphical User Interface but you’ll be surprised of how easy it is.

As with other interfaces, the CLI – Cisco Command Line Interface accepts Tabbing (hitting the “TAB” button) to auto-complete the words. But there are limitations on how this is used. For example, suppose you are typing a command that starts with “A” and the CLI database contains 10 commands that starts with “A”, surely the TAB input won’t initiate.

Consider these:

Apple

Append

Alpha

In the Cisco CLI, if you typed “A” then hit “TAB”, nothing will happen. However, if you typed “Al” then hit “TAB”, this will auto-complete to “Alpha”. The CLI checks for ambiguity.

Next, the CLI is made up of three (3) main levels and a lot of sub-levels after. For the purpose of this lesson, we will only discuss the three (3). .

1. User Mode – this is represented by a “>” sign. Router>

This mode is used to invoke a few show commands and there’s nothing much to do here.

2. Privilege Mode – this is represented by a “#” sign. Router#

This mode has a few show commands and save commands but that’s all.

3. Global Configuration Mode – this is represented by “(config)#”. Router(config)#

This mode or level is where we are interested in. This is the part where we can configure the entire device.

Well, since we are talking about the command line, let’s list the commands to change CLI Mode.

1. Enable – this is the first command that you will type over and over again whenever you are going to configure devices. This simply gets you from User Mode to Privilege Mode.

2. Configure Terminal – you will have to input this command every time. This moves you from Privilege Mode to Global configuration Mode. Once you are in this mode, you can do configurations that will affect the whole device. You will also have the option to go a little further to configure specific areas such as the ports on the devices, the virtual and console terminals etc.

3. Now to go back 1 level just type "exit".

Some of the configurations you can do here are:

1. Changing the device’s hostname. A hostname is the name of the device.

2. Setting a password for the device. Well, we all want our devices to be secured, don't we?

3. Creating a banner or as we call it often, the log on message.

Check out the video for the tutorial: Cisco Initial Configurations

Packet Tracer Student Version here: Cisco Packet Tracer