[ovs-dev] [PATCH ovn] ovn-northd: Forward ARP requests on localnet ports.

[Dumitru Ceara]

Commit 32f5ebb06226 limited the ARP/ND broadcast domain but in scenarios
where ARP responder flows are installed only on chassis that own the
associated logical ports ARP requests should still be forwarded on
localnet ports because the router pipeline should be executed on the
chassis that owns the logical port. Only that chassis will reply to the
ARP/ND request.

Reported-by: Michael Plato <michael.plato at tu-berlin.de>
Reported-at: https://mail.openvswitch.org/pipermail/ovs-discuss/2020-March/049856.html
Fixes: 32f5ebb06226 ("ovn-northd: Limit ARP/ND broadcast domain whenever possible.")
Signed-off-by: Dumitru Ceara <dceara at redhat.com>
---
 northd/ovn-northd.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
index f648d2e..b76df05 100644
--- a/northd/ovn-northd.c
+++ b/northd/ovn-northd.c
@@ -5903,8 +5903,12 @@ build_lswitch_rport_arp_req_flow_for_ip(struct sset *ips,
     ds_put_cstr(&match, "}");
 
     /* Send a the packet only to the router pipeline and skip flooding it
-     * in the broadcast domain.
+     * in the broadcast domain (except for the localnet port).
      */
+    if (od->localnet_port) {
+        ds_put_format(&actions, "clone { outport = %s; output; }; ",
+                      od->localnet_port->json_key);
+    }
     ds_put_format(&actions, "outport = %s; output;", patch_op->json_key);
     ovn_lflow_add_with_hint(lflows, od, S_SWITCH_IN_L2_LKUP, priority,
                             ds_cstr(&match), ds_cstr(&actions), stage_hint);
-- 
1.8.3.1