While there are some graphical tools available to configure
Cisco routers, the vast majority of Cisco device configuration involves
entering commands at the IOS interface command line. Unfortunately, that often
means a good amount of typing—and spending a large part of your day hacking
away at the keyboard.

So what can you do to lessen that time? A good place to
start is to work on speeding up your command-line skills.

The Cisco IOS offers a number of ways—built into the IOS—to
make entering commands easier. For example, you can use the alias command to shorten the process
and dispel some of the repetition.

However, as with anything at the command line, rarely will
it tell you how it can help make your life easier. That’s why it’s a good idea
to learn tricks that will make your life easier when entering commands. And if
you ever take any of the CCIE lab exams,
being able to type commands quickly will be imperative to passing the test.

Let’s look at three ways you can speed up your command-line
skills in the Cisco IOS interface.

Look up

One of the most frustrating things about quickly entering
commands is that you can easily make a mistake. The quickest and easiest way to
fix a mistake is pressing the up arrow key. This takes you to the previous
command, where you can edit and fix the error.

You can also use this key to scroll through the previous 20
commands you’ve entered (20 is the default number). But keep in mind that each
mode has a different command history. So, Privileged Mode (Router#) has one
command history, while Global Configuration Mode (Router(config)#) has an
entirely different history.

However, if you really want to, you can change the command
history. Here’s an example:

Router# term history size 256

Here’s an example of the show history command:

Router# show history
 sh running-config view full
 show diag
 show 
 show history
 show terminal
 conf t
 show logging
 conf t
 term history size 256
 show history
Router#

Cut it off

When looking for ways to speed up command entry, it’s
important to remember that the Cisco IOS will accept the least number of
characters that match a unique command. I recommend taking advantage of this
feature with every command you enter.

Let’s look at some examples:

  • Rather
    than entering the show ip route
    command, you can just type sh ip ro.
  • Instead
    of entering the show
    running-configuration     command, you can just type sh run.
  • Rather
    than entering the show ip interface
    brief     command, you can just type sh ip in brie.

The Cisco IOS will automatically complete any string of
unique characters that you type when you press the [Tab] key. So, using one of
our examples, you can type show run
and press [Tab], and the IOS will resolve it to show running-configuration.

Use Cisco’s built-in shortcuts

The Cisco IOS includes built-in features that allow the quick
movement and editing of command strings. You can delete entire words, delete to
the end of the line, and move the cursor to the beginning of the line, end of
the line, or the third word in the line.

Here are some examples:

  • Press
    [Ctrl]W to delete the previous word.
  • Press
    [Ctrl]A to move to the beginning of the line.
  • Press
    [Ctrl]E to move to the end of the line.

For a complete list of command-editing features, check out Cisco’s
Using
the Command-Line Interface documentation.

Combine these tips for quicker command entry

Let’s look at an example that uses all three of these
tricks. Let’s say you want to disable and then re-enable an interface, and you’re
in Interface Configuration Mode for this interface. First, type sh, and press [Enter]. This runs the shutdown command and disables the
interface.

Next, you want to re-enable the interface. Press the up arrow
key to find the sh command. Then, press
[Ctrl]A (which takes you to the beginning of the line), and type no in front of sh, press the spacebar, and press [Enter]. This runs the no shutdown command and re-enables the
interface. Using these shortcuts, you just disabled and re-enabled an interface
by pressing a total of eight keys.

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David Davis has worked
in the IT industry for 12 years and holds several certifications, including
CCIE, MCSE+I, CISSP, CCNA, CCDA, and CCNP. He currently manages a group of
systems/network administrators for a privately owned retail company and
performs networking/systems consulting on a part-time basis.