[ltp] T42 wireless problem - DCHPDiscover for wlan0 finds nothing.

[Marius Gedminas]

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On Tue, Apr 25, 2006 at 06:03:52AM -0500, Tim Ottinger wrote:
> I'm running a Thinkpad T42, using the built-in wireless radio, running De=
bian
> Etch.  I update my machine pretty frequently, probably twice a week or mo=
re.
> I have never had any trouble with Linux wireless until recently.=20

If you add

  auto wlan0
  iface wlan0 inet dhcp
        wireless-mode managed
        wireless-essid any

to /etc/network/interfaces, then it should Just Work.

>    0000:02:02.0 Ethernet controller: Atheros Communications, Inc.=20
> AR5212 802.11abg NIC (rev 01)

Ignore the suggestion to upgrade the ipw2200 driver -- you have an Atheros
wireless card, not an Intel one.

> Current state of my problem is that I can't connect to wireless access=20
> points.
> I can "iwconfig", and I can "iwlist ap" just fine.
>=20
> However:
>=20
> > $ ifup wlan0
>    Internet Software Consortium DHCP Client 2.0pl5
>    Copyright 1995, 1996, 1997, 1998, 1999 The Internet Software Consortiu=
m.
>    All rights reserved.
>=20
>    Please contribute if you find this software useful.
>    For info, please visit http://www.isc.org/dhcp-contrib.html
>=20
>    sit0: unknown hardware address type 776
>    sit0: unknown hardware address type 776
>    Listening on LPF/wlan0/00:05:4e:51:2f:64
>    Sending on   LPF/wlan0/00:05:4e:51:2f:64
>    Sending on   Socket/fallback/fallback-net
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 10
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 13
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 14
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 8
>    DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 4
>    No DHCPOFFERS received.
>    No working leases in persistent database.
>    Exiting.
>=20
>    Failed to bring up wlan0.

I think it is necessary to set the connection mode to "managed" and maybe
specify the essid ("any" ought to pick the strongest available one) with
iwconfig before you can perform DHCP queries.  Try

    $ sudo iwconfig wlan0 mode managed
    $ sudo iwconfig wlan0 essid any
    $ sudo ifup wlan0

If you add those wireless-xxx entries I mentioned above to your
/etc/network/interfaces, then ifup will invoke iwconfig for you.

> Up until sometime last week (sigh -- I don't know the event) it worked ju=
st fine.
> I would love some information about how to debug this, or how to fix it.=
=20

You can check with 'iwconfig wlan0' whether your network card has associated
with the correct access point, and what's the link quality.

> Now this is the consistent result.  I'm stuck using windows for=20
> wireless  connectivity
> which saddens me.

I feel your pain.

Marius Gedminas
--=20
=2E..Unix, MS-DOS, and Windows NT (also known as the Good, the Bad, and
the Ugly).
		-- Matt Welsh

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