RE: suggestion for simplifying IGMPV3/MLDV2 to discard EXCLUDEmode

> > An initial interface state of each host is (m, INCLUDE, NULL).
> > When the host changes the state (m, INCLUDE, s1) (due to (m,s1) join),
> > it sends ALLOW(m,s1), not TO_IN(m,s1), because the host's initial
> > filter mode has been INCLUDE.
> 
> Well, one could believe that there is no initial state.
> or there is "NULL" state.
> 
> I don't find anything in the RFC that claims there is any initial state.

Does the sentence in section 5.1 correspond to my thought?

   If no interface
   state existed for that multicast address before the change (i.e., the
   change consisted of creating a new per-interface record), or if no
   state exists after the change (i.e., the change consisted of deleting
   a per-interface record), then the "non-existent" state is considered
   to have a filter mode of INCLUDE and an empty source list.
--
Hitoshi Asaeda