April 2007

I’m running the beta of Feisty, and wanted to get my wacom tablet working. The general linux instructions direct you to edit XF86Config.conf or xorg.conf. For Feisty, this should be xorg.conf, but I couldn’t find the file, even after re-running updatedb and using locate, as well as

find /etc/X11 | xargs egrep InputDevice.

Fortunately, I found an entry in the ubuntu forums which explicitly addresses the issue. (I still don’t know why, given that I’ve not done anything to directly interact with my X setup, I am missing the file.) The set of entries is here: http://ubuntuforums.org/showthread.php?p=2437635 .

This command will generate a working, default xorg.conf for you, which you can then edit to the edge of sanity and back:

sudo dpkg-reconfigure xserver-xorg -pcritical.

In an earlier post, I talked about Cisco command line regular expressions, and held off on giving any good examples of using the CLI regexp tools to get ‘AND’ functionality. ( I pointed out there that the ‘|’ (pipe symbol) could be used as a simple ‘OR’ function.)
Here are some easy regexp’s that function (more as less) as simple Boolean ‘AND’s.

Here’s a scenario: you’re auditing one of your routers, checking to make sure privilege levels are what they should be for individual users, and that commands that have been moved into non-default privilege levels that appear to be correctly defined.
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From time to time, I need to access a complete config stored by the rancid application under CVS, so I can get a good look (more than just the line diffs) at the configuration. I’m not skilled at using CVS, in fact, I only use enough to get done exactly what I need. However, if you’re in the same boat , this might come in handy for you as well.

Here are the steps I use to recover an older version of configuration stored by the rancid process in a CVS structure.

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When I first took the CCNA, I used a shortcut to get subnet masks worked out correctly. This was important, since I didn’t know cold what a /14 was, a /22 was, and so on. I got away by knowing only the classful subnet breaks (/8, /16, /24, /32 — hereafter referred to without the slashes) along with the knowledge that subnets all work (in binary) from left to right with the progression 128, 192, 224, 240, 248, 252, 254, then 255. Rather, I knew those pieces, and I knew what came in the middle, and that was enough to get me through the binary and decimal conversions. Let me explain.

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