On 09/04/2012 04:29 AM, Martin Kletzander wrote: Yes, that's the intent of allowing <virtualport> settings in <network> objects - it divorces the guest config from the specifics of the network it's connecting to (which is really an attribute of the *host* that the guest happens to be running on, so could change). Basically, the guest names a network it wants to use, and a network of that name should be available on both hosts, with <virtualport> setup appropriately. If this doesn't work, it's a bug. In that case (and also if it does work!) please report back here. As rare as it is to have either 802.1Qbg or 802.1Qbh hardware available for testing, it is even more rare to have both available at the same time, so the results of your testing would be very valuable! Yes, but more complicated to setup, which implies more fragile. Definitely prefer the first method Martin suggested. That is only the case for 1) very new libvirt (0.10.0+) and 2) <interface type='network'>. It's purpose is to allow specifying, for example, both an openvswitch interfaceid and an 802.11Qbh profileid at the same time (for cases when the guest doesn't know whether the network it connects to will be openvswitch or 802.1Qbh, and wants to specify the appropriate setting for both possibilities).