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

[Pekka Savola <pekkas@netcore.fi>]

On Wed, 16 Oct 2002, ken lindahl wrote:
> At 09:31 PM 10/16/2002 +0300, Pekka Savola wrote:
> >Most switches work fine as is I believe, though flooding the multicasts
> >all over the segment.. yet where is SSM?  I sure would like to have it..
> 
> that definition of working "fine" doesn't work for my campus. berkeley
> researchers are investigating the use of relatively high-bandwidth
> multicast (>10Mbps per stream) and i really don't want that flooding
> on departmental segments with one receiver. other Internet2-connected
> institutions are in similar positions, i think.

Smaller segments can be used if that's really a problem (100/FD should
probably handle some 20-30Mbit/s of multicast per port without anyone
noticing anything but I haven't tested).  

SSM <-> ASM reflectors (I dunno if these have been specified but should
not be difficult) could be used if that's really a problem.
 
> i agree with Bill's earlier comment: lack of IGMPv3 snooping in current
> switches is a major obstacle to IPv4 SSM deployment, and lack of MLD
> snooping will become an impediment to IPv6 SSM deployment.

There are many different kind of multicasts.  If SSM would be hitting big,
it would have come through with the other multicast applications (not so
high volume), but where is it now..?

I guess that's a good way to explain why SSM may be failing.

Sure, IGMPv3, MLDv2 snooping would be nice but it seems hypocritical to
say this is the reason why SSM isn't being used..

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords