--- prelude: > Prior to Newton, the neutron-openvswitch-agent used 'ovs-ofctl' of_interface driver by default. In Newton, 'of_interface' defaults to 'native'. This mostly eliminates spawning ovs-ofctl and improves performance a little. upgrade: - To retain the old default for neutron-openvswitch-agent, use 'of_interface = ovs-ofctl' in the '[ovs]' section of your openvswitch agent configuration file. - By default, the native interface will have the Ryu controller listen on 127.0.0.1:6633. The listen address can be configured with of_listen_address and of_listen_port options. Ensure that the controller has permission to listen at the configured address.