Installing the Kismet wireless scanner on Gentoo Linux on a Thinkpad T40
Kismet is a very handy wireless scanning and capture program. Unlike programs such as Netstumbler, Kismet allows you to capture wireless traffic. This could, of course, be used for both good and evil, so I leave it up to you to do what you will.
Kismet is in Portage, but it lags a bit behind the current version (2008.05 is in Portage and 2010.07R1 is the latest as of this writing). You should be able to get the latest version by using an overlay, but I’m not keen on using overlay software unless I really need the bleeding edge. Use portage to install Kismet:
%sudo emerge -av net-wireless/kismet
Once installed, you’ll need to modify the config file before you begin scanning. Open /etc/kismet.conf in your favorite text editor and add your login to the ‘suidsuser’ variable. There are quite a few options to configure, but the one you must configure is a capture source. For our needs, change the ‘source=’ line to the following:
source=ipw2100,eth1,ipw
I suppose this would work for most of the older IPW2100-based Centrino notebooks since the Centrino chipset is the same. Save the config and exit. You should be able to type ‘kismet’ at a terminal and have the client and server automatically start. If this doesn’t work, you may have to manually change the kismet server to set uid. Do the following:
%sudo chmod +s /usr/bin/kismet_server
Try launching the program again. If you see a text based interface and some SSIDs, you’re good to go! If not, you may have to fiddle with your settings a bit more. Either way, happy scanning!