RE: New draft on embedding the RP address in IPv6 multicast address

["Rami Lehtonen" <rampe@cs.tut.fi>]

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Hi,

I also see another problem in embedding the RP address in IPv6 multicast
address. Now the sources have to know the address of the RP they are going
to use, when selecting the multicast group address. Is there need for RP
address discovery/announcement?

Another problem that was identified already is that we have only one RP per
group. This means that sources from the another domain than the RP can't use
their own domain RP without RP-RP signalling (e.g. RP-RP Register messages).

Also the receiver domain's RP does not join SPT (S, G) but (RP, G) which
might be suboptimal. It could change afterwards to (S, G) when it learns the
source address but this needs additional state creation signalling
throughout the domains in between.

And last point is that if there are no active sources for that group, this
model allows Internet wide multicast state creation (from receiver(s) in
another domain to the multicast group RP in another domain) compared to the
domain wide state creation in IPv4 MSDP model. This is because we don't have
any source active information available.

- Rami Lehtonen