Bug 1910304

This is not only that the command is printing out wrong parameters, functionality is broken too. Without those parameters, multicast works as broadcast flooding all of the interfaces as igmp snooping is disabled.

I tried it out, BZ reprodicable, adding DFG:NFV for visibility
With the following puddle 2020-11-13.1

Hello:

The integration bridge "mcast_snooping_enable" and "other_config:mcast-snooping-disable-flood-unregistered" options are set during the OVS agent initialization, according to the configuration parameter "OVS.igmp_snooping_enable".

Any value set on those configuration options will be overwritten during the OVS initialization when [1] is executed. In order to set a desirable value, please modify "OVS.igmp_snooping_enable".

*NOTE*: any manual action or configuration on the Open vSwitch is not recommended. OVS agent is in charge of handling and configuring this service. No manual configuration commands should be executed.

Regards.

[1]https://github.com/openstack/neutron/blob/4d33a64931fd35583952e45dbc8fd7272cb67c0d/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py#L1339

I did some validation on an OSP 16.1 compute node; Does this look right?  

$ sudo ovs-vswitchd --version
ovs-vswitchd (Open vSwitch) 2.13.2
DPDK 19.11.3

# where I started with the default:
$ sudo ovs-vsctl get bridge br-int other_config
{mac-table-size="50000", mcast-snooping-disable-flood-unregistered=False}

#set to true
crudini --set /var/lib/config-data/puppet-generated/neutron/etc/neutron/plugins/ml2/openvswitch_agent.ini ovs igmp_snooping_enable True

#restart neutron ovs agent
$ sudo podman restart neutron_ovs_agent

#multicast snooping now enabled:
$ sudo ovs-vsctl get bridge br-int other_config
{mac-table-size="50000", mcast-snooping-disable-flood-unregistered=True}

This can be set in OSP 16.1 using the NeutronEnableIgmpSnooping Overcloud parameter:
  https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.1/html/overcloud_parameters/networking-neutron-parameters

I'm validating using ComputeExtraConfig to set this parameter for OSP 13. I'll update the bug with the results.  

Meanwhile, these guides need to be updated. I think we should add a WARNING or NOTE that these settings are volatile and add the parameter solutions to the OSP 16.1 guide and the as-of-yet unverified ComputeExtraConfig options for OSP 13 guide. 

OSP 13 Networking guide needs to be updated:
  https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/13/html/networking_guide/sec-connect-instance#enable-ovs-mcast-snoop-prov-networks
  Still has:
    sudo ovs-vsctl set Bridge br-int mcast_snooping_enable=true
    sudo ovs-vsctl set Bridge br-int \
      other_config:mcast-snooping-disable-flood-unregistered=true

OSP 16.1 Networking guide needs to be updated:
  Still has:
    sudo ovs-vsctl set Bridge br-int mcast_snooping_enable=true
    sudo ovs-vsctl set Bridge br-int \
      other_config:mcast-snooping-disable-flood-unregistered=true

Thanks, 

CFields

After further discussion, existing parameters set in tripleo can set the required options, and this is tracked in an in-progress doc bug, let's follow-up on this one

*** This bug has been marked as a duplicate of bug 1916481 ***