Appendix B. Summary of Changes from MLDv1

The MLDv2 protocol, when compared to MLDv1 [RFC2710], adds support for "source filtering", i.e., the ability for a node to report interest in listening to packets only from specific source addresses, as required to support Source-Specific Multicast [RFC3569], or from all but specific source addresses, sent to a particular multicast address. MLDv2 is designed to be interoperable with MLDv1.

The specific changes are:

• The Node State includes a set of sources for each multicast address.
• The State Change Report (formerly Unsolicited Report) adds "filter mode change" records and "source list change" records.
• The Multicast Address Specific Query (formerly Group Specific Query) includes a set of sources.
• The new Multicast Address and Source Specific Query type.
• The Report message format is changed to support source lists.
• The Query message format is changed to support source lists.
• The Maximum Response Code is redefined.
• The Robustness Variable is added to the Query.
• The Suppress Router-Side Processing (S) flag is added to the Query.
• The Querier's Query Interval Code (QQIC) is added to the Query.
• The Number of Sources (N) and Source Address [i] fields are added to the Query.