Hi all: I'm facing problems trying to define a bridge on Ubuntu 16.04, using libvirt 3.4.0. When I try to do: root@ubuntu-180:/tmp# virsh iface-define iface-testbr1.xml I get the following error: error: Failed to define interface from iface-testbr1.xml error: this function is not supported by the connection driver: virInterfaceDefineXML What can i do to make this function works normally? THX. The xml file as: <interface type='bridge' name='testbr1'> <mtu size='1500'/> <bridge stp='on' delay='1500'> <interface type='ethernet' name='enp9s0'> <link speed='1000' state='up'/> <mac address='0c:c4:7a:c1:63:17'/> </interface> </bridge> </interface> root@ubuntu-180:/tmp# uname -a Linux ubuntu-180 4.4.0-62-generic #83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux