[2008.9] Wifi very unreliable

Alex Osborne ato at meshy.org
Tue Sep 30 12:11:48 CEST 2008


Matthias Apitz wrote:
>  I'm trying to bring up the eth0 with
>
> # ifup eth0
>
> this works very unreliable; in (let's say) 8 of 10 cases it can't
> associate to the AP, even not after fresh re-boots and independently if
> the AP at my home works with WEP or in my office with WPA;
>   
I found that with wpa_supplicant there was a problem with disconnecting 
from an AP.  The essid would apparantly not get cleared properly on the 
card (although iwconfig would show it as cleared) and until you manually 
cleared it, wpa_supplicant would just sit in a loop trying to connect 
and getting authentication timeouts.  You can see these message if you 
run wpa_cli.  I worked around it by adding a pre-up that clears the essid:

allow-hotplug eth0
iface eth0 inet manual
  wpa-driver wext
  wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
  pre-up iwconfig eth0 essid off

iface default inet dhcp
iface home inet dhcp

This seems to work reliably for me except that I still have to ifdown 
and ifup when I move to a different AP.  So if manually connecting with 
iwconfig works for you, you could try same workaround. Here's what my 
wpa_supplicant.conf looks like:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev

network={
    ssid="XXXXXXX"
    key_mgmt=NONE
    wep_key0=XXXXXXXXXXXXXXXXXXXXXX
    wep_tx_keyidx=0
    id_str="home"
}

network={
    key_mgmt=NONE
}

Note that this is with Debian, not 2008.9 -- I'm not sure whether 
Om2008.9 supports exactly the same /etc/network/interfaces syntax as Debian.

Cheers,

Alex




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