unstable network trouble

[Gerd Knorr <kraxel@suse.de>]

   Hi,

With current unstable (hg7500) I have the problem that networking for 
domU's doesn't work reliable.  Seems to be more or less random, havn't 
seen any pattern yet, sometimes it works normally and sometimes it doesn't.

In case it does _not_ work it looks like this (domain 1 runs fine, 
domain 3 is broken):

The xen-backend device is present in sysfs:

   master-xen root ~# ls /sys/devices/xen-backend
   .  ..  vbd-1-768  vbd-1-832  vbd-3-51712  vif-1-0  vif-3-0

The vif network interface is missing:

   master-xen root ~# ip link ls | grep vif
   3: vif0.0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue
   6: vif1.0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue

/etc/xen/scripts/vif-bridge is not called according to /var/log/messages:

   master-xen root /var/log# grep vif-bridge /var/log/messages
   Oct 27 15:22:50 master-xen logger: /etc/xen/scripts/vif-bridge: up 
XENBUS_PATH=backend/vif/1/0

The backend entries in xenstore look just fine:

master-xen root ~# xenstore-dump backend/vif
1/
     0/
         bridge           xenbr0
         mac              aa:00:57:4f:25:a7
         handle           0
         script           /etc/xen/scripts/vif-bridge
         frontend-id      1
         domain           debian
         frontend         /local/domain/1/device/vif/0
3/
     0/
         bridge           xenbr0
         mac              aa:00:ca:d7:83:e1
         handle           0
         script           /etc/xen/scripts/vif-bridge
         frontend-id      3
         domain           gentoo
         frontend         /local/domain/3/device/vif/0

ideas anyone?

cheers,

   Gerd