H3C Technologies H3C S3600 Series Switches - Manual (Page 451)

6-2
Figure 6-1 Before and after IGMP Snooping is enabled on Layer 2 device
Basic Concepts in IGMP Snooping
IGMP Snooping related ports
As shown in Figure 6-2 , Router A connects to the multicast source, IGMP Snooping runs on Switch A
and Switch B, Host A and Host C are receiver hosts (namely, multicast group members).
Figure 6-2 IGMP Snooping related ports
Router A Switch A
Switch B
Eth1/0/1 Eth1/0/2
Eth1/0/3
Eth1/0/1
Eth1/0/2
Receiver
Receiver
Host A
Host B
Host C
Host D
Source
Multicast packets
Router port
Member port
Ports involved in IGMP Snooping, as shown in Figure 6-2 , are described as follows:
z Router port: A router port is a port on the Layer 3 multicast device (DR or IGMP querier) side of the
Ethernet switch. In the figure, Ethernet 1/0/1 of Switch A and Ethernet 1/0/1 of Switch B are router
ports. A switch registers all its local router ports in its router port list.
z Member port: A member port is a port on the multicast group member side of the Ethernet switch.
In the figure, Ethernet 1/0/2 and Ethernet 1/0/3 of Switch A and Ethernet 1/0/2 of Switch B are