Re: [pim] IPv6 Inter-domain Multicasting and Address Assignments

Hello;


On 2/23/07, Tim Chown <[email protected]> wrote:
> On Thu, Feb 22, 2007 at 08:36:39PM -0500, Marshall Eubanks wrote:
> >
> > On 2/22/07, Tim Chown <[email protected]> wrote:
> >
> > This has been used since at least early 2003; it was first presented
> > at the Summer 2003
> > IETF in Vienna - see
> >
> > http://www.6net.org/events/workshop-2004/durand.pdf
>
> Yes, Embedded-RP came out of 6NET work.    There was a lot of early IPv6
> multicast development and testing done in 6NET and on the m6bone which
> emerged from TF-NGN just before 6NET started.
>
> > >A big win for v6 is that you dont need an ASN for GLOP like v4, you can
> > >just form multicast groups from your unicast allocated prefix(es).
> > >
> >
> > Note that there has been a big discussion about assignment of IPv6
> > addresses - see
> >
> > http://www.arin.net/policy/proposals/2005_1.html
>
> This is a good point - if you want provider independent multicats group
> addresses you need provider independent unicast space to base the 3306
> or embedded-rp group address upon.
>
> > >And with a lot of /64's in an IPv6 site, you can (as we have) assign an
> >
> > Most assignments are /48s
>
> To sites, yes, but if you want to allow more unique multicast group
> addresses to be used, what we decided to do was issue a /64 per application.
> By doing that the application can determine how to utilise the multicast
> group bits and they won't clash with other groups as they would if your
> 3306 addresses were purely generated from a /48.   Well, we're trying this
> at the moment to see how it works.   An allocation service would certainly
> be useful, something to respond to a request to 'please allocate me a 32
> bit group ID for this 96 bit group prefix' would be nice.

My point was just that once you get v6 PI space you have lots of
addresses to play with, but this is very interesting.

Should this allocation service be done by an RIR ? (This could be
assigned for "Multicast Applications" for each RIR and then they could
hand them out to requestors.
That would require a RFC first, of course.)

Marshall

>
> Another thing we're tinkering with is organisational SAP style advertisements
> where an application has a /64 based 3306 prefix and then uses group ID zero
> for the announcements.   For that example p2p app, it allows a site's
> available services to be discovered anywhere via a 'well known' group.
>
> But the point is that v6 multicast has the big win of allowing a site to
> create its own globally unique multicast group addresses (lots of them!)
> from just its unicast prefix.    No need for an ASN.    And thus to be able
> to also try new creative schemes to use that address space.   Something you
> just can't do in v4.
>
> --
> Tim
>