Re: DHCP transaction timing out, even though working

[Dan Williams <dcbw redhat com>]

On Mon, 2006-04-24 at 21:04 +1200, Simon Geard wrote:
> Hi all...
> 
> I've spent a little effort lately in getting NetworkManager to work on a
> LinuxFromScratch-based desktop, using a variant of the Redhat backend. I
> don't think this is the area failing, I mention it only as background.
> 
> 
> When I try to connect to an AP, I get the password prompt, then I see a
> lot of output from wpa_supplicant. That settles down, then sometime
> later I get:
> 
> NetworkManager: <information>   Device 'ath0' DHCP transaction took too
> long (>45s), stopping it.
> 
> However, this appears spurious, since before it gives up with the
> timeout, the dhclient process has been started (by dhcdbd), and the
> connection is working fine.
> 
> So, can anyone suggest why NM is timing out?

Are you sure you have the correct magic in dhclient and dhclient-script
to forward the DHCP results back to NM?  Is there any indication in the
logs that dhclient is actually getting an IP address?

As a quick test, you can run "dhclient -1 ath0" as root from a terminal
while NM is waiting for the DHCP transaction to complete.  This will
stop all over NM's dhclient, but that's fine, we want to know if the
card's settings are correct enough that DHCP will work.

The second thing you could do is grab ethereal, and set it up to monitor
packets going out of the machine during that time period.  You'll have
to set up the packet capture settings, but don't press start until NM
executes wpa_supplicant.  Be sure to to it _between_ when wpa_supplicant
gets started, and when the DHCP client gets started.  In any case, that
will let you see if any packets are going out.

Dan