Configuring IGMP snooping fast learn ports globally

Configuring fast learn on a port enables faster response to topology change notifications. When spanning tree changes the port state from blocked to forwarding, the device acting as querier will immediately send a general query on the fast learn enabled port. Then the device acting as a non-querier will replay the joins. This will help in faster convergence of multicast flows.

Prerequisites

You must be in the configuration context, as indicated by the switch(config)# prompt.

Procedure

Configure one or more ports as IGMP snooping fast learn ports using the following command.

ip igmp snooping fastlearn <PORT-LIST>

For example, the following command configures ports 1/1/1-1/1/3 as fast learn ports:

switch# configure terminal
switch(config)# ip igmp snooping fastlearn 1/1/1-1/1/3