Comment 42 for bug 1732067

Yi Yang, I don't think the purpose of this patch is learning the MAC address. The fix is implemented by adding a flow that sends traffic destined to a MAC directly to a specific interface, thus short-circuiting the default NORMAL action which (correctly) broadcasts the traffic to all interfaces except the incoming one.

So from the high-level point of view, after this fix is applied, maybe you don't actually need br-int to learn the destination MAC address. It's only necessary if there still existed traffic that didn't match the new direct flow and instead would fall back to the flow with NORMAL action. If you witnessed such a case, you're probably right to create a new bug report.

I don't think neutron-server has anything to do with this change. Flows are populated by agents, so only neutron-openvswitch-agent would have to be restarted in my opinion.

I also don't think that firewall_driver setting is relevant to this change. The flow added in this patch, as I see it (correct me if I'm wrong), sits before any firewall rules whether you're using iptables_hybrid or ovs. This patch is related to traffic forwarding, not traffic filtering.