Public bug reported: Commit d02fb560aa35c4931d40000e8ca4c0e4105299b7 (1)(2) to Neutron disabled 'mcast_flood' on localnet ports, in order to avoid multicast packet duplication. This introduces a regression because outbound multicast traffic from VMs is no longer sent to the provider network unless it is part of a multicast group that OVN has snooped. This makes it impossible for something external to OpenStack to subscribe to a multicast group running on a VM (in OpenStack) unless another VM (in OpenStack) subscribes to it first (because the multicast traffic never leaves the OVS).
In my opinion https://review.opendev.org/c/openstack/neutron/+/797418 has to be reverted and a change implemented in ovn itself. 1 https://review.opendev.org/c/openstack/neutron/+/797418 2 https://bugs.launchpad.net/neutron/+bug/1933207 ** Affects: neutron Importance: Undecided Status: New ** Bug watch added: github.com/ovn-org/ovn/issues #125 https://github.com/ovn-org/ovn/issues/125 -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1967996 Title: [OVN] External subscribers to feed generated in Openstack fails if no internal VM is subscribed to that feed first Status in neutron: New Bug description: Commit d02fb560aa35c4931d40000e8ca4c0e4105299b7 (1)(2) to Neutron disabled 'mcast_flood' on localnet ports, in order to avoid multicast packet duplication. This introduces a regression because outbound multicast traffic from VMs is no longer sent to the provider network unless it is part of a multicast group that OVN has snooped. This makes it impossible for something external to OpenStack to subscribe to a multicast group running on a VM (in OpenStack) unless another VM (in OpenStack) subscribes to it first (because the multicast traffic never leaves the OVS). In my opinion https://review.opendev.org/c/openstack/neutron/+/797418 has to be reverted and a change implemented in ovn itself. 1 https://review.opendev.org/c/openstack/neutron/+/797418 2 https://bugs.launchpad.net/neutron/+bug/1933207 To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1967996/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
