Enabling MLD snooping querier

In an IPv6 multicast network that is running MLD, a multicast router or Layer 3 multicast switch sends periodic MLD general queries, so that all Layer 3 multicast devices can establish and maintain multicast forwarding entries, in order to forward multicast traffic correctly at the network layer. This router or Layer 3 switch is called the "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 must 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 queries. Multicast forwarding entries can then be created and maintained at the data link layer.

Follow these steps to enable the MLD snooping querier:

	NOTE: It 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 might affect MLD querier elections because it sends MLD general queries with a low source IPv6 address.