Re: Wireless interface stopped working in Etch

[Chris Lale <chrislale@untrammelled.co.uk>]

Florian Kulzer wrote:
> On Fri, Nov 10, 2006 at 16:38:50 +0000, Chris Lale wrote:
>   
> > My Edimax EW-7108pcg PCMCIA wifi card (rt2500 driver) works perfectly in 
> > my constantly upgraded version of Etch (Testing). I installed the rt2500 
> > driver some weeks ago. The same driver, built in the same way, will not 
> > work in a fresh install of Etch in a new partition on the same machine 
> > (Thinkpad T20).
> >
> > In both cases I built the rt2500 module from the rt2500-source package 
> > using module assistant. The resulting modules package was the same version:
> >
> > rt2500-modules-2.6.17-2-686 version 1.1.0+cvs20060620-3+2.6.17-9
> >
> > On the fresh install I have also tried the rt2x00 module. On the fresh 
> > install I have also tried ndswrapper for the Edimax card and another 
> > card (D-Link DWL-G650), but no luck. The interface will not come up 
> > (using ifup).
> >
> > With the rt2500 module, the card is detected and the rt2500 module loads 
> > OK in both cases. The only difference that I can find between the two 
> > systems is that the name allocated to the wireless interface is 
> > different. On the working system, the command iwconfig gives wlan0 for 
> > the wireless interface:
> >
> > lo          no wireless extensions.
> > eth0      no wireless extensions.
> > irda0     no wireless extensions.
> > wlan0    RT2500 Wireless ESSID:"essid-of-my-modem/router"
> >             [...]
> > sit0       no wireless extensions.
> >
> > On the fresh install, the interface's name has been changed from wlan0 
> > to eth1. (Also, irda0 and sit0 are not detected):
> >
> > lo          no wireless extensions.
> > eth0      no wireless extensions.
> > eth1     RT2500 Wireless ESSID:""
> >            [...]
> >
> > When I installed ndiswrapper on the fresh install, the wireless 
> > interface appeared as wlan0_rename
> >
> > lo                      no wireless extensions.
> > eth0                  no wireless extensions.
> > wlan0_rename   RT2500 Wireless ESSID:""
> >                         [...]
> >
> > Does anyone know what might be causing the wireless interface to have 
> > different names on the fresh install of Etch? Any suggestions gratefully 
> > received.
> >     
>
> The usual suspect for issues with the names of network devices is
> /etc/udev/rules.d/z25_persistent-net.rules.
>
> As far as the general problem with the device is concerned: It seems
> that eth1 in the new install is accepted as a wireless network device,
> so it should work. 

I think you must be right - this is not the problem. I substituted wlan0 
for eth1 in /etc/udev/rules.d/z25_persistent-net.rules and rebooted 
(there must be a better way). iwconfig now reported wlan0. I also 
modified /etc/network/interfaces, substituting wlan0 for eth0, but the 
interface still would not work.
> Did you adjust the data in /etc/network/interfaces to
> match the new name of the device? Ifup needs this information to set the
> ESSID, encryption key, etc.
>
>   

Yes, this all looks OK:

iface wlan0 inet static
address 192.168.1.3
netmask 255.255.255.0
gateway 192.168.1.1
wireless-essid solarsystem
wireless-key 0123456789


It seems that the kernel modules are different. lsmod reports what looks 
like a difference in size:

original system:
rt2500   149988   1

fresh install:
rt2500   151748   1

Is it possible to copy the module over from the original system to the 
new system? Which files are involved?


--
Chris.