1-15Configuring MLD Snooping QuerierConfiguration PrerequisitesBefore configuring MLD snooping querier, complete the following task:z Enable MLD snooping in the VLAN.Before configuring MLD snooping querier, prepare the following data:z MLD general query interval,z MLD last-member query interval,z Maximum response time for MLD general queries,z Source IPv6 address of MLD general queries, andz Source IPv6 address of MLD multicast-address-specific queries.Enabling MLD Snooping QuerierIn an IPv6 multicast network running MLD, a multicast router or Layer 3 multicast switch is responsiblefor sending periodic MLD general queries, so that all Layer 3 multicast devices can establish andmaintain multicast forwarding entries, thus to forward multicast traffic correctly at the network layer. Thisrouter or Layer 3 switch is called MLD querier.However, a Layer 2 multicast switch does not support MLD, and therefore cannot send MLD generalqueries by default. By enabling MLD snooping querier on a Layer 2 switch in a VLAN where multicasttraffic needs to be Layer-2 switched only and no Layer 3 multicast devices are present, the Layer 2switch will act as the MLD querier to send periodic MLD queries, thus allowing multicast forwardingentries to be established and maintained at the data link layer.Follow these steps to enable the MLD snooping querier:To do... Use the command... RemarksEnter system view system-view —Enter VLAN view vlan vlan-id —Enable the MLD snoopingquerier mld-snooping querier RequiredDisabled by defaultIt is meaningless to configure an MLD snooping querier in an IPv6 multicast network running MLD.Although an MLD snooping querier does not take part in MLD querier elections, it may affect MLDquerier elections because it sends MLD general queries with a low source IPv6 address.For details about MLD querier, see MLD Configuration of the IP Multicast Volume.Configuring MLD Queries and ResponsesYou can tune the MLD general query interval based on actual condition of the network.Upon receiving an MLD query (general query or multicast-address-specific query), a host starts a timerfor each IPv6 multicast group it has joined. This timer is initialized to a random value in the range of 0 to
