libvirt requires iptables to set up its networking. Reproducible: Always Steps to Reproduce: 1. emerge libvirt 2. /etc/init.d/libvirtd start 3. virsh net-create $your_network Actual Results: virsh # net-create /etc/libvirt/networks/foo.xml libvir: QEMU error : internal error failed to add iptables rule to allow DHCP requests from 'foo' : Invalid argument error: Failed to create network from /etc/libvirt/networks/foo.xml Expected Results: Network foo created from /etc/libvirt/networks/foo.xml
This has been fixed. use the network USE flag in newer versions.