ah  so here we never update the port  so we must check if the mac address is ok  after this change we always overwrite the mac address and update it to a value that does work  so it is actually really   dumb   what works today  if you happen to pass in a port with a matching mac address  it will work  and we make sure when we create ports we do not use the mac the user passed in  in all other cases we seem to just give up  if the hypervisor has some mac addresses  