H3C Technologies H3C S7500E Series Switches - Manual (Page 258)

9-2
Figure 9-1 Before and after MLD snooping is enabled on the Layer 2 device
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
MLD snooping forwards multicast data to only the receivers requiring it at Layer 2. It brings the
following advantages:
z Reducing Layer 2 broadcast packets, thus saving network bandwidth.
z Enhancing the security of multicast traffic.
z Facilitating the implementation of per-host accounting.
Basic Concepts in MLD Snooping
MLD Snooping related ports
As shown in Figure 9-2 , 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).