[libvirt] Problem in running libvirt-cim test suite

Hi, I trying to install libvirt-cim in my ubuntu-xen-3.2.1 machine. I am able to install all dependencies and libvirt-cim , but when I run cimtest which has given in libvirt.org, I am getting following error message * Starting test suite: libvirt-cim ERROR - Failed to create Virtual Network 'cimtest-networkpool' Unable to create network pool cimtest-networkpool Please check your environment.* Is there any special networking setup is require to run cimtest. Any help would be appreciated. Apologies if this topic has been covered already. I can't find it anywhere using Google Thanks, seenu.