From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gerd Knorr <kraxel@suse.de>
Subject: Re: unstable network trouble
Date: Mon, 31 Oct 2005 11:58:10 +0100
Message-ID: <4365F8C2.4040809@suse.de>
References: <4360DCDE.6000207@suse.de>	<20051027151234.GX13783@leeni.uk.xensource.com>
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To: Ewan Mellor <ewan@xensource.com>
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> Hmm, no, seems to be a missing hotplug event.

Sticked some printk's into the net backend, looks like a xenbus issue:

domU boot with broken network:

   netback_probe: add backend watch
   netback_probe: add frontend watch
   netback_probe: done
   frontend_changed: called
   frontend_changed: called
   frontend_changed: called
   frontend_changed: called

domU boot with working network:

   netback_probe: add backend watch
   netback_probe: add frontend watch
   netback_probe: done
   backend_changed: called
   backend_changed: hotplug online
   netback_hotplug: called
   frontend_changed: called
   frontend_changed: called
   device vif2.0 entered promiscuous mode
   xenbr0: port 3(vif2.0) entering learning state
   xenbr0: topology change detected, propagating
   xenbr0: port 3(vif2.0) entering forwarding state
   frontend_changed: called
   frontend_changed: called
   frontend_changed: called

Note that backend_changed is never called in the first case.

cheers,

   Gerd