Figure 242 MLD snooping related ports

The following describes the ports involved in MLD snooping:

•Router port—Layer 3 multicast device-side port. Layer 3 multicast devices include designated routers and MLD queriers. As shown in Figure 242, GigabitEthernet 1/0/1 of Switch A and GigabitEthernet 1/0/1 of Switch B are router ports. A switch records all its local router ports in its router port list.

Do not confuse the "router port" in MLD snooping with the "routed interface" commonly known as the "Layer 3 interface." The router port in MLD snooping is a Layer 2 interface.

•Member port—Multicast receiver-side port. As shown in Figure 242, GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 of Switch A and GigabitEthernet 1/0/2 of Switch B are member ports. A switch records all local member ports in its MLD snooping forwarding table.

Unless otherwise specified, router ports and member ports in this document include both dynamic and static ports.

NOTE:

When MLD snooping is enabled, all ports that receive IPv6 PIM hello messages or MLD general queries with source addresses other than 0::0 are considered dynamic router ports.

Aging timers for dynamic ports in MLD snooping

Timer

Description

Message received

Action after the timer

before the timer

expires

 

 

expires

 

 

 

Dynamic router port aging timer

When a port receives an MLD general query with the source address other than 0::0 or IPv6 PIM hello message, the switch starts or resets an aging timer. When the timer expires, the dynamic router port ages out.

MLD general query with the source address other than 0::0 or IPv6 PIM hello message.

The switch removes this port from its router port list.

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