Comment 2 for bug 2028795

Reviewed: https://review.opendev.org/c/openstack/neutron/+/890230
Committed: https://opendev.org/openstack/neutron/commit/489cdf5f16a97d0cc63eb88d031e780ed1f75cff
Submitter: "Zuul (22348)"
Branch: stable/xena

commit 489cdf5f16a97d0cc63eb88d031e780ed1f75cff
Author: Jakub Libosvar <email address hidden>
Date: Wed Jul 26 18:28:29 2023 +0000

    dvr: Avoid installing non-dvr openflow rule on startup

    The tunneling bridge uses different openflow rules depending if the
    agent is running in DVR mode or not. With DVR enabled initial rule was
    installed that caused traffic coming from the integration bridge to be
    flooded to all tunnels. After a few miliseconds this flow was replaced
    by a DVR specific flow, correctly dropping the traffic. This small time
    window caused a network loop on the compute node with restarted agent.

    This patch skips installing the non-dvr specific flow in case OVS agent
    is working in DVR mode. Hence the traffic is never flooded to the
    tunnels.

    Closes-bug: #2028795

    Conflicts:
            neutron/plugins/ml2/drivers/openvswitch/agent/ovs_dvr_neutron_agent.py

    Signed-off-by: Jakub Libosvar <email address hidden>
    Change-Id: I3ce026054286c8e28ec1500f1a4aa607fe73f337
    (cherry picked from commit ba6f7bf83e6f17048a97f781aa16bf4a643a53d2)