3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring MLD-Related Functions 659
Configuring
MLD-Related
Functions
Configuration
Prerequisites
Before configuring MLD-related functions, complete the following task:
■ Enable MLD Snooping in the VLAN
Before configuring MLD-related functions, prepare the following data:
■ MLD general query interval
■ MLD last-member query interval
■ Maximum response time for MLD general queries
■ Source IPv6 address of MLD general queries
■ Source IPv6 address of MLD group-specific queries
■ Whether to enable the function of dropping the unknown IPv6 multicast data
Enabling MLD Snooping
Querier
In an IPv6 multicast network running MLD, a multicast router or Layer 3 multicast
switch is responsible for sending periodic MLD general queries, so that all Layer 3
multicast devices can establish and maintain multicast forwarding entries, thus to
forward multicast traffic correctly at the network layer. This router or Layer 3
switch is called MLD querier.
However, a Layer 2 multicast switch does not support MLD, and therefore cannot
send MLD general queries by default. By enabling MLD Snooping querier on a
Layer 2 switch in a VLAN where multicast traffic needs to be Layer-2 switched only
and no Layer 3 multicast devices are present, the Layer 2 switch will act as the
MLD querier to send periodic MLD general queries, thus allowing multicast
forwarding entries to be established and maintained at the data link layer.
Follow these steps to enable MLD Snooping querier:
c
CAUTION:
■ An MLD Snooping querier does not take part in MLD querier election.
■ It is meaningless to configure an MLD Snooping querier in an IPv6 multicast
network running MLD; in fact, this may affect MLD querier elections because
an MLD Snooping querier sends MLD general queries with a low source IPv6
address.
Configuring MLD Timers You can tune the MLD general query interval based on actual condition of the
network.
To do... Use the command... Remarks
Enter system view system-view -
Enter VLAN view vlan vlan-id -
Enable the MLD Snooping
querier
mld-snooping querier Required
Disabled by default