[COLUG] Auto-attaching to arbitrary wireless networks

[Rob Funk]

The strange thing about being among the first on the block to use some new 
technology is that when a newer (and probably easier) way comes along it 
tends to get ignored... and then sometimes the hard way stops working, 
and a search begins for that newer (presumably easier) way.

In this case it's wireless networking.  I started using 802.11b back 
around when the Apple Airport came out, and got to "help test" an early 
version of OSU's wireless infrastructure.  I still have and use the Cisco 
AiroNet 802.11b card I bought around 1999-ish.  It's always been my most 
reliable wireless card, but I also have an rt2500-based Zonet/Ralink 
802.11g card (mainly for home use) and a USB-connected prism-based 
802.11b adapter specially made to go on the back of my Compaq Evo laptop.  
I know my way around iwconfig, and when forced I can muddle my way 
through wlanctl-ng a bit.

I'm now using Kubuntu Gutsy.  I've managed to set things up so I can plug 
in the Cisco card, boot up the machine, go near an open access point, and 
have it automatically associate.  I did this by putting these lines 
in /etc/network/interfaces:

auto eth1
iface eth1 inet dhcp
	wireless-mode managed
	wireless-essid any
auto wifi0
iface wifi0 inet dhcp
	wireless-mode managed
	wireless-essid any

However, when there are multiple access points nearby, I have to 
use "iwlist scanning" to see what's nearby, then use iwconfig to set the 
channel and essid, and ifdown/ifup the interface.

knetworkmanager doesn't seem to help much (sadly no convenient list of 
nearby access points).  For a while I've had things configured so that 
the Ralink card defaults to my home settings, and the Cisco card defaults 
to wherever else I happen to go most often, but the Ralink driver has 
changed so the new interface name for that conflicts with the interface 
name for the Compaq wireless module (both wlan0), which ideally I'd like 
to turn into my random-public-access-point interface.

So, is there an easier way to arbitrarily detect and connect to random 
wireless networks with these various interfaces?  No points for a 
half-GUI, half-command-line solution, since that's worse than the 
all-command-line solution I use now.

My dream would be to be able to set up a series of essids (optionally 
ending with "any") to try until one succeeds, and attach to that.  That 
would eliminate my hack of a different card for each different network.  
As far as I know that's not currently possible, though I'd love to be 
proven wrong.

-- 
==============================|   "A microscope locked in on one point
 Rob Funk <rfunk at funknet.net> |Never sees what kind of room that it's in"
 http://www.funknet.net/rfunk |    -- Chris Mars, "Stuck in Rewind"