Multicast Listener Discovery
Protocol for discovering IPv6 multicast listeners
From Wikipedia, the free encyclopedia
Multicast Listener Discovery (MLD) is a component of the Internet Protocol Version 6 (IPv6) suite. MLD is used by IPv6 routers for discovering multicast listeners on a directly attached link, much like Internet Group Management Protocol (IGMP) is used in IPv4. Instead of being implemented as a separate protocol, the protocol is embedded in ICMPv6. MLDv1 is similar to IGMPv2[1] and MLDv2 similar to IGMPv3.[2].
Protocol
The following ICMPv6 message types are used:
ICMPv6 message type values[2] Message Type value Multicast Listener Query 130 MLDv1 Multicast Listener Report 131 MLDv2 Multicast Listener Report 143 Multicast Listener Done 132
All MLDv1/MLDv2 messages have a link-local IPv6 Source Address (fe80::/10). MLDv2 Reports may be sent from the unspecified address (::/128) if no valid link-local IPv6 source address is present.[2]
MLDv2 Multicast Listener Reports are sent to ff02::16, to which all MLDv2-capable multicast routers listen.[2]
Support
Several operating systems support MLDv2:
- Windows Vista and later[3]
- FreeBSD since release 8.0[4]
- The Linux kernel since 2.5.68[5]
- macOS[6]