Re: vlan + bridge + xen

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, May 26, 2007 at 10:25:17PM +0200, Lars-Johan Liman wrote:
> Yow!
> 
> I'm trying to make vlans work too, and Google took me to the appended
> message, but I'm struggling with your statement. It's a bit on the
> brief side if you're not deep down into the layers upon layers of
> deception ...  err ... networking. :-)
> 
> Is it possible to make a domU communicate both with external hosts and
> with its dom0 using Q-tagged packets over the same interface?
> 
> Par example:
> 
> host A domU:
>   vlan1 vlan 1 vlanif xennet0 10.0.0.1/24
>   xennet0 up
> 
> host A dom0:
>   vlan1 vlan 1 vlanif fxp0 10.0.0.2/24
>   fxp0 up
> 
> host B dom0:
>   vlan1 vlan 1 vlanif fxp0 10.0.0.3/24
>   fxp0 up
> 
> Is it possible to make a configuration with bridges and other voodoo,
> so that I can sit on the host A domU and successfully do:
> 
>   ping -n 10.0.0.2
>   ping -n 10.0.0.3
> 
> I'm trying to create a system where the host A domU can jump between
> motherships (A-dom0 and B-dom0) without having to use different
> interfaces.
> 
> I can make either/or happen, but not both, by adding either
> A-dom0-fxp0 _or_ A-dom0-vlan1 to A-bridge0, but adding both creates
> "severe unreachability" ...

Yes, because bridge and vlan on the same physical interface won't work
properly. What you could do is attach vlan interfaces to the xvif network
interface in dom0 (the other end of the link between dom0 and domU).
You'll probably have to hack a bit the xen scripts for this, or do it
by hand once domU is up. Then you can bridge the vlans in dom0.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--