HP A6600 Configuration Manual page 25

As shown in Figure 12, Router A connects to the multicast source, IGMP snooping runs on Switch A and
Switch B, and Host A and Host C are receiver hosts (namely, multicast group members).
Figure 12 IGMP snooping related ports
Router A
GE1/0/1
GE1/0/3
GE1/0/1
Source
Router port
Member port
Multicast packets
Ports involved in IGMP snooping, as shown in
• Router port—A router port is a port on an Ethernet switch that leads the switch toward a Layer 3
multicast device (DR or IGMP querier). In the figure, GigabitEthernet 1/0/1 of Switch A and
GigabitEthernet 1/0/1 of Switch B are router ports. The switch registers all its local router ports in its
router port list.
• Member port—A member port is a port on an Ethernet switch that leads the switch toward multicast
group members. In the figure, GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 of Switch A and
GigabitEthernet 1/0/2 of Switch B are member ports. The switch registers all the member ports on
the local device in its IGMP snooping forwarding table.
Table 6 Aging timers for dynamic ports in IGMP snooping and related messages and actions
Timer
Dynamic router port
aging timer
Dynamic member port
aging timer
The port aging mechanism of IGMP snooping works only for dynamic ports; a static port will never age
out.
Switch A
GE1/0/2
Receiver
GE1/0/2
Host C
Switch B
Host D
Description
For each dynamic router
port, the switch sets a
timer initialized to the
dynamic router port
aging time.
When a port
dynamically joins a
multicast group, the
switch sets a timer for the
port, which is initialized
to the dynamic member
port aging time.
14
Receiver
Host A
Host B
Figure 12, are described as follows:
Message before expiry
IGMP general query of
which the source address
is not 0.0.0.0 or PIM
hello
IGMP membership report
Action after expiry
The switch removes this
port from its router port
list.
The switch removes this
port from the IGMP
snooping forwarding
table.