CCIE Pursuit Blog

August 22, 2007

Beware the Q!

Filed under: Cisco,Cisco Certification,IOS — cciepursuit @ 12:32 pm

When logging out of a Cisco device, I use “lo”.  Occasionally, I’ll have someone watching over my shoulder and they will ask why I use “lo” when most people use “exit”.  I learned to use “lo”(alias for “logout”) way back in the day when I was studying for my first CCNA attempt (back in 2000).  The study guide that I used advised that “logout” was the “official” Cisco method for logging out of a device.  I have no idea if this truly is(was) the case or not.  I got used to using “lo” and have used it ever since.

Whenever I execute a command that generates a large amount of output (such as “show run”) and I want to break out of the command, I use “l”.  I could use (nearly) any character, but I use “l” because it’s the first letter of my name (there goes my Internet anonymity  🙂 ).  A few years ago I was in a training class and the instructor (a CCIE) told me that the “official” Cisco character to use in this case is “q”.  He told me that another reason that I should use “q” is so that I do not accidently type “lo” when I use “l”.

I can hear you thinking, “Wow.  This is really fascinating.  What’s his point?”  Well, the other day I had an engineer over my shoulder while I was troubleshooting a router.  The WAN connection was bouncing, so I had dialed into the router via a modem connected to the AUX port.  Unfortunately, every command was taking a long time to execute because the router was trying to authenticate the commands with a TACACS+ server.  The connection to the server was bouncing with the WAN link, so I had to wait until it timed out (or I got lucky and the command got through while the link was up).  I had executed some command that generated a large amount of output.  I got what I needed and was going to type “l” to break out of the command.  The engineer over my shoulder is a CLI stickler.  He will go off every time he sees someone use “wr” instead of “copy run start”.  He also hates that I use “lo” instead of “exit”.  Not wanting to endure one of his pointless sermons, I hit “q” to break out of the command.

One of two things must have happened:

1) I hit “q” twice.
2) I hit “l” (force of habit) and then hit “q”.

Either way, I was suddenly logged out of the router.  If you enter “q” you will “quit” your session and be logged out.  Ah crap.  I avoided the CLI sermon, but I caught the full brunt of the “Why did you log out of the router?  You know that you could lock us out of the….” tirade.  I hit enter and everything was okay.  I shut down the WAN link and went on from there.

The lesson is that although “q” may be the official Cisco method of breaking out of a command (I’ve never verified this) but you need to make sure that you don’t accidently log yourself out of a device.  With “l”, you’ll only confuse the router (% Ambiguous command:  “l”) and not log yourself out.  🙂

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1 Comment »

  1. You know I have had that happen to me. I don’t quite remember how I got started with using Q to quit looking at something with a long string of output, but that darn Q has bitten me in the butt a couple of times. I am in the process of training myself to use something other than Q, hmmm maybe S will work. S is short for sucka, which is what I feel like every time I accidentally log myself out of a router.

    Comment by Amp — August 22, 2007 @ 3:57 pm | Reply


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