I set a migration network today. At first I could not ping the other machines, but then I
realized the vlan was a tagged vlan in ovirt. I changed the switch ports to general and
tagged them and it worked. I don't know your network or config, but thought I would
pass this along. If you have a vlan configured in ovirt, the ports attaching to that
network card have to be tagged, not un-tagged.
Not sure if this will help but wanted to pass it along.