wlan/eth bridge stops working after a while: how to diagnose?

[Alexey Yudichev]

I've got ubuntu 9.10 (hostapd 0.6.9) + compat-wireless-2009-12-11 and
the box is acting as a basic wireless internet router. Driver is ath9k
and server adapter is D-Link DWA-547. All is working fine for 2-3 days
until all of a sudden wireless client (MacBook Pro) stops pinging any
hosts on a local network. The wireless association remains and hostapd
logs are not showing anything unusual. Restarting hostapd or even
networking does not help (although I believe restarting networking
does not work well on ubuntu anyway). Only rebooting the server helps.


What would you advise to check/debug or otherwise what would be the
best approach to diagnose the problem? I don't see anything
interesting in dmesg, messages or daemon.log at this point.

Thanks!