Comment 2 for bug 1887148

The call to setup_dvr_flows() also installs the drop rule. But this is not getting to run because setup_rpc blocks on the has_alive_neutron_server rpc. Some stable branches don't have this rpc, and they block on get_dvr_mac_address instead.

https://github.com/openstack/neutron/blob/5999716cfc4a00ac426e016eabbb51247ba0b190/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py#L268-L286