3Com Switch 8800 Advanced Software V5 Configuration Guide

650 CHAPTER 45: MLD SNOOPING CONFIGURATION
Figure 196 Before and after MLD Snooping is enabled on a Layer 2 device
Basic Concepts in MLD
Snooping
MLD Snooping related ports
As shown in Figure 197, Router A connects to the multicast source, MLD
Snooping runs on Switch A and Switch B, Host A and Host C are receiver hosts
(namely, IPv6 multicast group members).
Figure 197 MLD Snooping related ports
Ports involved in MLD Snooping, as shown in Figure 197, are described as follows:
■ Router port: A router port is a port on a Layer 2 switch that leads the switch to
a multicast router (Layer-3 multicast device) or the MLD querier on the subnet.
In the figure, Ethernet 1/1/10 of Switch A and Ethernet 1/1/10 of Switch B are
router ports. A switch registers all its local router ports in its router port list.
IPv6 multicast packet transmission
without MLD Snooping
Source
Multicast router
Host A
Receiver
Host B
Host C
Receiver
IPv6 multicast packets
Layer 2 switch
IPv6 multicast packet transmission
when MLD Snooping runs
Source
Multicast router
Host A
Receiver
Host B
Host C
Receiver
Layer 2 switch
Router A Switch A
Switch B
Eth1/1 /10 Eth1/1/1
Eth 1/1/2
Eth1 /1/10
Eth1/1 /1
Receive
r
Receiver
Host A
Host B
Host C
Host D
Source
IPv6 multicast packets
Router port
Member port