Are there any circumstances in PIM-SM where a non-DR router on a multi-access network will process an IGMP Membership report and forward the "join" message up to the RP? Pardon the ascii-art below (R2 is the DR for both of his interfaces), but what should happen when R2 issues a "join" for the receiver that he has downstream. Does R1 recognize that the source IP address is his DR and forward it up to the RP, or ignore it?
RP ----| R1 |----vlan-----dr*| R2 |*dr----------Receiver
Thanks,
Nabeel