Prior to this patch, ML2/OVS and ML2/OVN had inconsistent IGMP
configurations. Neutron only exposed one configuration option for IGMP:
igmp_snooping_enabled.
Other features such as IGMP flood, IGMP flood reports and IGMP flood
unregistered were hardcoded differently on each driver (see LP#2044272
for a more details).
These hardcoded values has led to many changes over the years tweaking
them to work on different scenarios but they were never final because
the fix for one case would break the other.
This patch introduces 3 new configuration options for these other IGMP
features that can be enabled or disabled on both backends. Operators
can now fine tune their deployments in the way that will work for them.
As a consequence of the hardcoded values for each driver we had to break
some defaults and, in the case of ML2/OVS, if operators want to keep
things as they were before this patch they will need to enable the new
mcast_flood and mcast_flood_unregistered configuration options.
That said, the for ML2/OVS there was also an inconsistency with the help
string of igmp_snooping_enabled configuration option as it mentioned
that enabling snooping would disable flooding to unregistered ports but
that was not true anymore after the fix [0].
[0] https://bugs.launchpad.net/neutron/+bug/1884723
Closes-Bug: #2044272
Change-Id: Ic4dde46aa0ea2b03362329c87341c83b24d32176
Signed-off-by: Lucas Alvares Gomes <lucasagomes@gmail.com>
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