[Fedora-xen] VLANs on DomU domains

[Pasi Kärkkäinen]

On Thu, Nov 23, 2006 at 09:45:20AM +0100, Bertho Stultiens wrote:
> Darryl Bond wrote:
> > I managed to get it to work something along the lines of your first
> > method before I read your email. I was also unsuccessful using your
> > second method.
> 
> It still eludes me why the second method does not work, but the first
> seems to be ok too. Users cannot change set setup, so there is no real
> risk involved.
> 
> 
> [snip]
> > I found that if I used VLANs on the Dom0 on eth0 then the trunk would
> > not pass through to the guests,  Hence why Dom0 is not using VLANs on eth0.
> > I did not do much research to discover why except that the instant I
> > removed the VLANs from Dom0 eth0 the VLAN networks started working on
> > the guest.
> 
> You have to take care here because in Dom0 you have ethX and pethX.
> Vlans on ethX(dom0) will work whereas those on peth0 apparently do not
> as expected. My current setup is like this:
> 
> peth0 -> xenbr0 -> vif0.0 -> eth0(Dom0)+IP-> eth0.42+IP
>                 -> vif1.0 -> eth0(Guest1) -> eth0.42+IP
>                 -> vif2.0 -> eth0(Guest2) -> eth0.42+IP
>                 -> ...
> 
> Dom0 is part of vlan 42 and my management (no routing between them
> enabled though). The uplink peth0 is a trunk with management untagged
> and vlan 42 tagged.
> 
> My guess why the other setup has problems lies in several parts.
> Firstly, the management MAC address (default fe:ff:ff:ff:ff:ff) of the
> second bridge must be different. I forgot to change that and have had
> problems with that before with STP enabled (bridge can otherwise not be
> uniquely identified). And secondly, juggling with peth0.X can only be
> done after xen has remapped the interfaces. The remapping occurs after
> the original network is brought up. I need to go through the xen scripts
> to get that right, I guess.
> 
> I'll have to do some more experimenting to get this pinned down because
> it actually is interesting to have bridges that can swap/map/juggle vlan
> tags.
> 

Hi!

Did you figure out the correct way to do this? (set up bridge per vlan interface in
dom0, and export/bridge only untagged frames to domU's).

-- Pasi