HP MSR2003 Configuration Manual page 24

Figure 11 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 DRs and IGMP
queriers. In
are the router ports. A Layer 2 device 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
•
GigabitEthernet 1/0/3 of Switch A and GigabitEthernet 1/0/2 of Switch B are the member ports.
A Layer 2 device 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
Dynamic
router port
aging timer
Dynamic
member port
aging timer
Figure 1 1, GigabitEthernet 1/0/1 of Switch A and GigabitEthernet 1/0/1 of Switch B
Description
When a port receives an expected
message, the Layer 2 device starts
or resets an aging timer for the port.
When the timer expires, the
dynamic router port ages out.
When a port dynamically joins a
multicast group, the Layer 2 device
starts or resets an aging timer for
the port. When the timer expires,
the dynamic member port ages out.
Figure 1
Expected message before
the timer expires
IGMP general query with the
source address other than
0.0.0.0 or PIM hello
message.
IGMP membership report.
14
1, GigabitEthernet 1/0/2 and
Action after the timer
expires
The Layer 2 device
removes the port from
its router port list.
The Layer 2 device
removes the port from
the IGMP snooping
forwarding table.