Symptom

An IE3300 running 17.3.4 may flood multicast for up to 2 minutes even though "no ip igmp snooping tcn flood" is configured on the interfaces.

Conditions

1) Incoming multicast stream i.e. destination 239.1.1.1 2) "no ip igmp snooping tcn flood" configured on interfaces 3) Topology Change Notification causes flooding.

Workaround

The following command can be used to mitigate some of the impact of this flooding by reducing its duration: ip igmp snooping tcn flood query count 1

Further Problem Description