I'm kind of wondering why libvirt defaults to 192.168.122.0/24 by default. It is a piece of address space which is relatively likely to conflict with address space used in the environment surrounding the machine. Since libvirtd is on by default if installed, this is particularly problematic. I would like to suggest either one of the following as default address space, unless the user has explicitly configured otherwise: 192.0.2.0/24 - reserved as "test and example network" 198.18.0.0/15 - reserved as "benchmark test network" See RFC 3330 and RFC 2544 for the definitions of these networks. Both of them are "should not appear on the public Internet" address blocks, and much less likely than the RFC 1918 address block (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16) to be encountered "in the wild" by a user. -hpa