Two versions of MLD are specified:
- MLDv1, defined by RFC 2710, Multicast Listener Discovery for IPv6
- MLDv2, defined by RFC 3810, Multicast Listener Discovery version 2 (MLDv2) for IPv6
MLDv1 is based on IGMPv2. MLDv2 is based on IGMPv3.
In addition, RFC 4604: Using Internet Group Management Protocol Version 3 (IGMPv3) and Multicast Listener Discovery Protocol Version 2 (MLDv2) for Source-Specific Multicast extends MLD to support source-specific multicast. For more information, refer to Ciena Vyatta Network OS Multicast Routing Configuration Guide.