Hey, I've opened a bug against ubuntu at [1]. I realize this is probably not a high priority, but I was just curious if it is possible to have libvirt configure a network and *not* run a DNS server on it (dnsmasq). Perhaps I could convince libvirt to run dnsmasq with '--port 0'? For my explicit use case i was hoping/expecting to run my own dns and dhcp servers, possibly a specific server bound only to that interface (as dnsmasq does). I just wanted libvirt to create the bridge and setup NAT (and automatically bring the network and any configured guests on it up on boot). Heres what I did. $ BRIDGE="mybr0"; IP="192.168.123.1"; $ cat > $BRIDGE.xml <<EOF <network> <name>$BRIDGE</name> <forward mode='nat'/> <bridge name='$BRIDGE' stp='off' delay='0' /> <ip address='$IP' netmask='255.255.255.0'> </ip> </network> EOF $ sudo virsh -c qemu:///system net-define $BRIDGE.xml $ sudo virsh -c qemu:///system net-start $BRIDGE ## See, after 'start' dnsmasq is running and usable on that interface. $ ps axw | grep dnsm | grep $BRIDGE.pid 9888 ? S 0:00 /usr/sbin/dnsmasq -u libvirt-dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/libvirt/network/mybr0.pid --conf-file= --except-interface lo --listen-address 192.168.123.1 $ dig +short @$IP www.ubuntu.com 91.189.90.41 -- [1] https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1053408