RE: suggestion for simplifying IGMPV3/MLDV2 to discard EXCLUDEmode

i have not encountered undue difficulties with excluding sources in my
snooping implementation, but a "lite" version of the IGMPv3/MLDv2
protocols with no excluded sources seems possible by ignoring source lists
in the TO_EX() and IS_EX() messages, producing the following simplified
router state machine with no excluded sources:


Router State   Report Rec'd  New Router State         Actions
------------   ------------  ----------------         -------

INCLUDE (A)    IS_IN (B)     INCLUDE (A+B)            (B)=GMI

INCLUDE (A)    IS_EX ( )     EXCLUDE ( , )            Delete (A)
                                                      Group Timer=GMI

EXCLUDE (X, )  IS_IN (A)     EXCLUDE (X+A, )          (A)=GMI

EXCLUDE (X, )  IS_EX ( )     EXCLUDE ( , )            Delete (X)
                                                      Group Timer=GMI

INCLUDE (A)    ALLOW (B)     INCLUDE (A+B)            (B)=GMI

INCLUDE (A)    BLOCK (B)     INCLUDE (A)              Send Q(G,A*B)

INCLUDE (A)    TO_EX ( )     EXCLUDE ( , )            Delete (A)
                                                      Group Timer=GMI

INCLUDE (A)    TO_IN (B)     INCLUDE (A+B)            (B)=GMI
                                                      Send Q(G,A-B)

EXCLUDE (X, )  ALLOW (A)     EXCLUDE (X+A, )          (A)=GMI

EXCLUDE (X, )  BLOCK (A)     EXCLUDE (X+A, )          (A-X)=Group Timer
                                                      Send Q(G,A)

EXCLUDE (X, )  TO_EX ( )     EXCLUDE ( , )            Delete (X)
                                                      Group Timer=GMI

EXCLUDE (X, )  TO_IN (A)     EXCLUDE (X+A, )          (A)=GMI
                                                      Send Q(G,X-A)
                                                      Send Q(G)


this would avoid excluding sources while maintaining interoperability with
"full" versions of the IGMPv3/MLDv2 protocols by adhering to a reduced
subset of their router state machine.

mark