DELL 9.7(0.0) User Manual

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ip igmp snooping last-member-query-interval
Fast Convergence after MSTP Topology Changes
When a port transitions to the Forwarding state as a result of an STP or MSTP topology change, the 
system sends a general query out of all ports except the multicast router ports. The host sends a 
response to the general query and the forwarding database is updated without having to wait for the 
query interval to expire.
When an IGMP snooping switch is not acting as a querier, it sends out the general query in response to 
the MSTP triggered link-layer topology change, with the source IP address of 0.0.0.0 to avoid triggering 
querier election.
Designating a Multicast Router Interface
To designate an interface as a multicast router interface, use the following command.
The system also has the capability of listening in on the incoming IGMP general queries and designate 
those interfaces as the multicast router interface when the frames have a non-zero IP source address. All 
IGMP control packets and IP multicast data traffic originating from receivers is forwarded to multicast 
router interfaces.
• Designate an interface as a multicast router interface.
ip igmp snooping mrouter interface
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Internet Group Management Protocol (IGMP)