CCNA Certification: Five Keystroke Combinations You Should Know
While the 640-801, 640-811, and 640-821 exams may ask you about one or two of these, you really have to get hands-on experience with these commands to master them. Even better, there are some key combinations that Cisco routers mention, but then don’t tell you what they are! Let’s take a look at a few of the more helpful key combinations, and conclude with the “secret” way to stop a ping or traceroute.
The up arrow on your keyboard is great for repeating the last command you typed. Let´s say you mis-enter an access-list. Instead of typing it from the beginning, just hit your up arrow to repeat it, then fix the problem.
CTRL-A takes the cursor to the beginning of a typed line. If you´ve written an extended ACL, you know that can be a very long command, and one you probably don´t want to retype. If you get a carat indicating there is a problem with the line, use your up arrow to repeat the command. If you see the error is near the beginning, use CTRL-A to move the cursor immediately to the beginning of the line. CTRL-E takes the cursor to the end of a typed line.
To move the cursor through a typed line without erasing characters, you’ve got a couple of options. I personally like to use the left and right arrows, but you can also use CTRL-B to move back and CTRL-F to move forward.
Finally, there’s the combination that Cisco mentions to you when you run ping or traceroute, but they don´t tell you what it is! If you send an extended ping or a traceroute, you could be looking at asterisks for a long time if you don´t know this one. In the following example, a traceroute is obviously failing:
R2#traceroute 10.1.1.1 Type escape sequence to abort. Tracing the route to 10.1.1.1 1 * * * 2 *
The problem is that you’re going to get 30 rows of those asterisks, which is frustrating and time-consuming at the same time. Note the router console message “Type escape sequence to abort”. That’s helpful – but what is it?
Here it is: Just type CTRL-SHIFT-6 twice, once right after the other. You won’t see anything on the router console, but the traceroute will terminate.
R2#traceroute 10.1.1.1 Type escape sequence to abort. Tracing the route to 10.1.1.1 1 * * * 2 * * * 3 R2#
The traceroute was successfully terminated. This combination works for pings as well, both extended and regular. Of all the keystrokes you can learn, this one is the most valuable!
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