[afnog] WiFi weirdness.

[Brian Candler]

On Fri, Aug 04, 2006 at 10:15:29AM +0300, Patrick Okui wrote:
> I have two Linksys Wireless-G access points in the office, one on 
> channel 6 the other on channel 11. For debugging purposes I set 
> different ESSIDs on each. Every once in a while I lose my 
> association with either of them[1], (and sometimes iwlist won't 
> show both access points). The configuration on both APs is the 
> defaults plus a whitelist of MAC addresses for the WiFi cards in 
> the office.
> 
> Running iwevent on linux gives me output similar to the attached 
> text file.[2] Each time I get the AP advertisement with the 
> 00:00:00:00:00:00 MAC I lose my association with my access point 
> irrespective of which access point I'm associated with.
> 
> Any ideas on how to debug and fix this?

Debug - no idea :-)

Fix - well, I don't know if it's a client-side or AP-side problem, but you
could try different firmware on the APs. Depending on the exact model you
have, you may be able to reflash them with OpenWrt -
http://wiki.openwrt.org/wiki/TableOfHardware

This gives you a mini Linux distribution with package support. Being able to
ssh into your access point is cool :-)

There's a fair learning curve associated (as Randy will attest), and a risk
that if you mess up the flashing you may turn your AP into a brick, so it's
good to have a spare one to test on. However there's a small mod you can do
to add one or two serial ports to it, which lets you control the boot loader
and overcome most bricking situations.

Beware: OpenWrt doesn't run on the latest (v5) WRT54G, because Linksys
halved the amount of flash and RAM. But they still sell the WRT54GL, which
is basically a rebadged v4. If you are buying a new access point, the Asus
WL500gx (x=Deluxe) is good, as it has two USB2.0 ports, or the Asus WL-HDD,
which has only one USB1.1 port, one ethernet port and no serial ports, but
can have a 2.5" hard drive fitted internally.

I've been doing quite a lot of work with OpenWrt recently, and am impressed.
Very usefully, you can set it up as an ethernet-to-wireless client bridge.
There's a pretty comprehensive set of pre-built packages available, even
Asterisk:
http://downloads.openwrt.org/whiterussian/rc5/packages/

People are using it with a USB-bluetooth dongle and a bluetooth headset :-)

The software development environment, which lets you build packages or the
entire system by cross-compiling on a Linux workstation, is also very well
put together.

Cheers,

Brian.