Multicast Listener Discovery Protocol
RFC 2710 defines specifications for the Multicast Listener Discovery (MLD) protocol. MLD is derived from IGMPv2 and is designed for IPv6. The operation of MLD is similar to IGMPv2. The major differences between IGMPv2 and MLD are as follows:
■ All the multicast devices on a subnet use a special IPv6 link-local address as their source address in their communication to other multicast devices. The use of the link-local source address prevents the MLD packet from traveling beyond the local link.
■ In MLD, when a host wants to leave a group, it sends a Done message. The Done message is similar to the IGMPv2 Leave message. It is addressed to the all-routers IPv6 link-local scope address, FF02::2.
■ In MLD, the router Queries are called Multicast Listener Queries. The General Queries are addressed to the all-nodes IPv6 link-local scope address, FF02::1. When a router receives a Done message, it sends a Multicast-Address-Specific Query. Its function is similar to IGMPv2 Group-Specific Query.
■ All the multicast devices on a subnet use a special IPv6 link-local address as their source address in their communication to other multicast devices. The use of the link-local source address prevents the MLD packet from traveling beyond the local link.
■ In MLD, when a host wants to leave a group, it sends a Done message. The Done message is similar to the IGMPv2 Leave message. It is addressed to the all-routers IPv6 link-local scope address, FF02::2.
■ In MLD, the router Queries are called Multicast Listener Queries. The General Queries are addressed to the all-nodes IPv6 link-local scope address, FF02::1. When a router receives a Done message, it sends a Multicast-Address-Specific Query. Its function is similar to IGMPv2 Group-Specific Query.
