Robert Elz wrote: > Date: Sun, 06 Oct 2002 10:38:32 -0400 > From: Margaret Wasserman <[EMAIL PROTECTED]> > Message-ID: <[EMAIL PROTECTED]> > > | You haven't provided the information that router B would use > | to make that determination. > > Brian Haberman provided an entirely good enough answer (which also was > that there wasn't enough information, but with different missing info). > > | Is router B configured so that the subnet-local zone IDs of its > | A-B and C-D interfaces are the same or different? > > What subnet local zone id ?
A border router between subnet local zones will have subnet zone ids assigned to each interface (see sections 5 & 6 of draft-ietf-ipngwg-scoping-arch-04.txt). > I wasn't aware that such a thing existed? > If it did, it would have to be assigned, which would make subnet-local > multicast jump out of the category of "no special config required" > that is (I think rightly) claimed for it, wouldn't it? Not necessarily. This was covered in a previous thread, but it is possible that a router could detect that a common prefix has been assigned to multiple interfaces and set the subnet-local zone id appropriately. > > | The unicast addresses uses on those links are immaterial to the > | decision of whether or not to forward subnet-local packets between > | these two links. > > Hmm ... that is exactly the opposite of what Brian said, and is also > contrary to what (little) I know about multicast forwarding. Generally > that's done based upon the (unicast) source address of the packet (along > with the destination address, naturally). Section 9 of draft-ietf-ipngwg-scoping-arch-04.txt explicitly states that when forwarding packets with a less than globally scoped destination address, the scope of the source address and the incoming interface zone id are taken into account. Brian -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
