> From: Robert Elz <[EMAIL PROTECTED]>

> Since nothing is ever sent from a multicast address, and since it can
> live on multiple ports (unlike a unicast address) it wouldn't matter if
> something was, the switch can't use that method to work out which ports
> a packet to a multicast address should be sent to.

Solicted node multicast group is an exception to "nothing is ever sent".

- MLD join would only be used when node does DAD, e.g. sends

   (1) MLD join with src=::
   (2) DAD probe with src=::

- for *ANY* other packet, that has src != ::, the source address
  implictly indicates the solicited node multicast group that this
  node belongs.

If the switch is mucking around with MLD messages, it would not be a
big deal for it to implicitly remember solicited node groups just by
tracking the IPv6 source addresses used by the packets. Much more
robust and  better solution than relying the single MLD report before
DAD, which might get lost anyway (or switch powered down temporarily).

> So, for every (general) multicast address, the node would have to run
> two protocols, the link level one, and the IP level one, so all the right
> devices know where multicast packets should get sent.

I don't see where the two different protocols come from. As explained,
membership of solicited node multicast group is implicitly indicated
by EACH packet the node sends.

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