What's the result of "virsh net-list"?
The default network is supposed to be created by default when you install libvirt.
Do you have anything in /etc/libvirt/qemu/networks/?
What's the result of "virsh net-list"?
The default network is supposed to be created by default when you install libvirt.
Do you have anything in /etc/libvirt/ qemu/networks/ ?