Create a NIC without an IP and watch stuff break

The GUI allows for creation of networks on cluster level, to which you can attach a NIC. It is not needed to define an IP for this NIC. Not adding an IP to an interface is a valid option in the menu: you can choose "None" for "Boot Protocol" when adding a NIC to a logical network.

But when I attach VM's to this network and try to start them, stuff breaks:

Thread-120::DEBUG::2012-11-16 12:46:21,763::vm::607::vm.Vm::(_startUnderlyingVm) vmId=`8b982672-1ca8-488b-a112-dcd0a7f8bc15`::_ongoingCreations released
Thread-120::ERROR::2012-11-16 12:46:21,764::vm::631::vm.Vm::(_startUnderlyingVm) vmId=`8b982672-1ca8-488b-a112-dcd0a7f8bc15`::The vm start process failed
Traceback (most recent call last):
  File "/usr/share/vdsm/vm.py", line 597, in _startUnderlyingVm
  File "/usr/share/vdsm/libvirtvm.py", line 1416, in _run
  File "/usr/lib64/python2.6/site-packages/vdsm/libvirtconnection.py", line 83, in wrapper
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 2490, in createXML
libvirtError: XML error: listen network 'vdsm-vm_only_network' had no usable address

 

Anyone else seeing this? My network is called 'vm_only_network'. I does not matter whether this network is or isn't the display network.