Subject: Re: Xen and VLANs
To: Johan Ihren <>
From: Manuel Bouyer <>
List: port-xen
Date: 01/07/2006 11:57:50
On Sat, Jan 07, 2006 at 10:42:23AM +0100, Johan Ihren wrote:
> >Yes, of course. When you have a xennetN in a virtual domain, there is
> >a corresponding interface in dom0 named xvifX.N, where X is the  
> >domain's
> >number. You can then route or bridge these interfaces, leaving the  
> >physical
> >interface out of the setup
> Umm, that's not what I wanted. I have a gazillion xvifN.M interfaces  
> (well, at least more than 30) and I wasn't after micromanaging most  
> of them from the dom0, especielly not for every state change among  
> the domUs. I do, however, realize that it is probably possible to do  
> that to achieve the behaviour I need that way.
> What I wanted was a xennet0 in my dom0 that I can connect to the same  
> bridge as my xennetN's in the domUs and then add all the VLANs on top  
> of that. That way things will continue to work when I add or remove  
> domUs. I.e. this should be a "local" xennet0 that the domU uses to  
> talk to xennetN's in the domUs, not a reflection of the xennetN's in  
> the domUs.

Ha, OK. Then you can probably to what you want with a tap(4) device.
You may need some program to read and discard data from the /dev/tapN
device for it to work, I didn't test this configuration.

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference