H3C Technologies H3C S12500-X Series Switches - Manual (Page 25)

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Figure 12 IGMP snooping related ports
The following describes the ports involved in IGMP snooping:
• Router port—Layer 3 multicast device-side port. Layer 3 multicast devices include designated
routers (DRs) and IGMP queriers. In
Figure 12 , Ten-GigabitEthernet 1/0/1 of Switch A and
Ten-GigabitEthernet 1/0/1 of Switch B are the router ports. A switch records all its router ports in
a router port list.
Do not confuse the "router port" in IGMP snooping with the "routed interface" commonly known as
the "Layer 3 interface." The router port in IGMP snooping is a Layer 2 interface.
• Member port—Multicast receiver-side port. In Figure 12 , Ten-GigabitEthernet 1/0/2 and
Ten-GigabitEthernet 1/0/3 of Switch A and Ten-GigabitEthernet 1/0/2 of Switch B are the
member ports. A switch records all its member ports in the IGMP snooping forwarding table.
Unless otherwise specified, router ports and member ports in this document include both static and
dynamic router ports and member ports.
NOTE:
When IGMP snooping is enabled, all ports that receive PIM hello messages or IGMP general queries with
the source addresses other than 0.0.0.0 are considered dynamic router ports. For more information about
PIM hello messages, see " Configuring PIM ."
Aging timers for dynamic ports in IGMP snooping
Timer Description
Expected messages
before the timer expires
Action after the timer
expires
Dynamic
router port
aging timer
When a port receives an IGMP
general query with the source
address other than 0.0.0.0 or a
PIM hello message, the Layer 2
device starts or resets an aging
timer for the port.
IGMP general query with the
source address other than
0.0.0.0 or PIM hello
message.
The switch removes the
port from its router port
list.