On 7/19/22 22:40, Dumitru Ceara wrote: > RFC 4541 "Considerations for Internet Group Management Protocol (IGMP) > and Multicast Listener Discovery (MLD) Snooping Switches" [0] states: > > For IGMP packets: > 2.1.1. IGMP Forwarding Rules > 1) A snooping switch should forward IGMP Membership Reports only to > those ports where multicast routers are attached. > > Alternatively stated: a snooping switch should not forward IGMP > Membership Reports to ports on which only hosts are attached. An > administrative control may be provided to override this > restriction, allowing the report messages to be flooded to other > ports. > > This is the main IGMP snooping functionality for the control path. > > Sending membership reports to other hosts can result, for IGMPv1 > and IGMPv2, in unintentionally preventing a host from joining a > specific multicast group. > > When an IGMPv1 or IGMPv2 host receives a membership report for a > group address that it intends to join, the host will suppress its > own membership report for the same group. This join or message > suppression is a requirement for IGMPv1 and IGMPv2 hosts. > However, if a switch does not receive a membership report from the > host it will not forward multicast data to it. > > In OVN this translates to forwarding reports only on: > a. ports where mrouters have been learned (IGMP queries were received on > those ports) > b. ports connecting a multicast enabled logical switch to a multicast > relay enabled logical router (OVN mrouter) > c. ports configured with mcast_flood_reports=true > > 2.1.2. Data Forwarding Rules > > 1) Packets with a destination IP address outside 224.0.0.X which are > not IGMP should be forwarded according to group-based port > membership tables and must also be forwarded on router ports. > > In OVN this translates to forwarding traffic for a group G to: > a. all ports where G was learned > b. all ports where an (external or OVN) mrouter was learned. > c. all ports configured with mcast_flood=true > > IGMP queries are already snooped by ovn-controller. Just propagate the > information about where mrouters are to the Southbound DB through means > of a custom IGMP_Group (name="mrouters"). > > Snooped queries are then re-injected in the OVS pipeline with outport > set to MC_FLOOD_L2 (only flood them in the L2 domain). > > Snooped reports are re-injected in the OVS pipeline with outport set to > MC_MROUTER_FLOOD (flood them to snooped mrouters and OVN mrouters). > > The same behavior applies to IPv6 too (MLD). > > [0] https://datatracker.ietf.org/doc/html/rfc4541 > > Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1933990 > Reported-at: https://github.com/ovn-org/ovn/issues/126 > Acked-by: Numan Siddique <num...@ovn.org> > Signed-off-by: Dumitru Ceara <dce...@redhat.com>
Lucas, sorry, I dropped your "Tested-by" by accident. Would you have some time by any chance to do a quick sanity test, just in case? There was no code change between v1 and v2 of this patch. Thanks, Dumitru _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
