H3C Technologies H3C S12500-X Series Switches - Manual (Page 116)

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Configuring MLD snooping
Overview
MLD snooping runs on a Layer 2 switch as an IPv6 multicast constraining mechanism to improve multicast
forwarding efficiency. It creates Layer 2 multicast forwarding entries from MLD messages that are
exchanged between the hosts and the router.
As shown in
Figure 36 , when MLD snooping is not enabled, the Layer 2 switch floods IPv6 multicast
packets to all hosts. When MLD snooping is enabled, the Layer 2 switch forwards multicast packets of
known IPv6 multicast groups to only the receivers.
Figure 36 Multicast packet transmission processes without and with MLD snooping
Basic MLD snooping concepts
MLD snooping related ports
As shown in Figure 37 , MLD snooping runs on Switch A and Switch B, and Host A and Host C are
receiver hosts in an IPv6 multicast group.