Configuring Mld Snooping; Overview; Basic Concepts In Mld Snooping - H3C S5500-EI Configuration Manual

Configuring MLD snooping

Overview

Multicast Listener Discovery (MLD) snooping is an IPv6 multicast constraining mechanism that runs on
Layer 2 devices to manage and control IPv6 multicast groups.
By analyzing received MLD messages, a Layer 2 device that runs MLD snooping establishes mappings
between ports and multicast MAC addresses and forwards IPv6 multicast data based on these
mappings.
As shown in
to all devices at Layer 2. With MLD snooping enabled, the Layer 2 switch forwards IPv6 multicast packets
destined for known IPv6 multicast groups to only the receivers that require the multicast data at Layer 2.
This feature improves bandwidth efficiency, enhances multicast security, and helps per-host accounting
for multicast users.
Figure 67 Before and after MLD snooping is enabled on the Layer 2 device

Basic concepts in MLD snooping

MLD snooping related ports
As shown in
Switch B, and Host A and Host C are receiver hosts as members of an IPv6 multicast group.
Figure 67, without MLD snooping enabled, the Layer 2 switch floods IPv6 multicast packets
Figure 68, Router A connects to the multicast source, MLD snooping runs on Switch A and
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