---
prelude: >
    Prior to Newton, the default option for 'ovsdb_interface'
    was 'vsctl'. In Newton 'ovsdb_interface' defaults to
    'native'. This change switches the way of communication
    with OVSDB from the ovs-vsctl tool to Open vSwitch python
    api to improve out-of-the-box performance for typical
    deployments.
upgrade:
    - To keep the old default value use 'ovsdb_interface = vsctl'
      in '[ovs]' section of openvswitch_agent.ini
      (common path '/etc/neutron/plugins/ml2/openvswitch_agent.ini')
      if there is a separate openvswitch agent configuration file;
      otherwise apply changes mentioned above to ml2_conf.ini
      (common path '/etc/neutron/plugins/ml2/ml2_conf.ini').
    - The native interface configures ovsdb-server to listen for
      connections on 127.0.0.1:6640 by default. The address can be
      configured with the ovsdb_connection config option. Ensure that
      ovsdb-server has permissions to listen on the configured address.