[Xen-devel] Re: Xen-devel digest, Vol 1 #798 - 2 msgs

[Evan Bigall <evan.bigall@xxxxxxxxxxx>]

Why bother use VLANS in dom-U
  

Well, I'm porting a large piece of software that makes extensive use of vlans, configuring them itself, I was hoping to change as little as possible.

I use bridge, setup VLANS on Domain-0, and bridge each eth0.x on 
Domain-0 to ethy on dom-U.
That way dom-U only sees eth0, eth1, eth2, and so on. It works flawlessly.

It does seem to work, and I might need to switch to that. I think I'd have to ssh to dom0 to set it up though which might be a bit awkward.

I'm curious though why the bridging doesn't seem to work.  Shouldn't it transparently pass the vlan tags through?

After some more experimentation I have this.

In dom1, I've configured eth0.5. In dom0, the bridge contains the Xen vif, and eth0.  The physical nic eth0 is connected via a loopback cable to another machine which also has vlan5 on eth0.

With this setup I cannot ping the ip on eth0.5 in dom1 on the Xen box.  The arps seem to arrive correctly but do not get replied to.

I've tried various things like adding eth0.5 to the bridge in dom0, but nothing seems to allow me to ping to the vlan in the vm from another physical box (I can get connections on vlans between vm's on the same physical machine).

Evan