Sadly no Qos priority tags defined.
If this were the case, and the physical switch was dropping the packets, I would think that the VM's wouldnt be able to talk with anything outside the virtual infrastructure. As the machine connects to a gig switch and from there goes to the router. But this isnt the case. The VM's can talk to other things on the network (which goes through other physical switches), just when trying to get to the router it fails.
Am I correct in that statement or is my understanding of things wrong?