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Re: [Xen-users] Yet another question about multiple NICs

On Mon, Dec 20, 2010 at 10:12 AM, Philippe Combes
<Philippe.Combes@xxxxxxxxxxx> wrote:
>> So it's only impossible to ping the domU from other machines on the
>> network (and vice versa)?
>> I think Fajar is probably right with his guess that your physical
>> switches are managed. That means they do traffic filtering on their
>> ports based on the mac addresses.
>> Which switch models do you use on your two networks?
> I already answered Fajar in this thread: when the FIRST vif of dom1 is
> connected to dom0's eth1, then the behaviour on that switched LAN is normal,
> while the traffic on the routed LAN of dom0's eth0 issues the bug.
> So my issue is definetely related to the instanciation of the SECOND
> interface of dom1, whatever network it is connected to. Or there is some
> kind of black magic underneath...

"black magic" is the word I'd use to describe Xen's default
network-bridge script :D

To narrow-down possible cause, can you DISABLE xen's default network
bridge script (or in your case, network-bridge-wrapper, replace it
with /bin/true) and setup bridges MANUALLY like JP's example in

You'll then have br0 and br1 bridges where you setup IP addresses, and
also use that in domU's config.

Personally I always create my own bridges instead of relying on Xen's
network-bridge script (at that time I needed vlan and bonding support,
which is not possible with the default network-bridge script)


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