When a client joins a network, is the client included in the ff02::1 IPv6 multicast group, which "broadcasts" to all nodes on the segment. OR, do I have to subscribe to the group using Multicast listener discovery with a report query including the multicast address group to subscribe to: ff02::1 in this case, I am guessing? Thanks.
1 Answer
No, this specific group is exempt from MLD.
RFC 3810 (MLDv2):
The link-scope all-nodes multicast address, (FF02::1), is handled as a special case. On all nodes -- that is all hosts and routers, including multicast routers -- listening to packets destined to the all-nodes multicast address, from all sources, is permanently enabled on all interfaces on which multicast listening is supported. No MLD messages are ever sent regarding neither the link-scope all-nodes multicast address [...]
RFC 2710 (MLDv1):
The link-scope all-nodes address (FF02::1) is handled as a special case. The node starts in Idle Listener state for that address on every interface, never transitions to another state, and never sends a Report or Done for that address.
[...]
MLD messages ARE sent for multicast addresses whose scope is 2 (link-local), including Solicited-Node multicast addresses [ADDR- ARCH], except for the link-scope, all-nodes address (FF02::1).
RFC 4541 (Considerations for IGMP and MLD snooping switches):
[...] MLD is mandated for addresses with scope 2 (link-scope) or greater. The only exception is the address FF02::1 which is the all hosts link-scope address for which MLD messages are never sent. Packets with the all hosts link-scope address should be forwarded on all ports.
