RE: The state of IPv6 multihoming development

[Iljitsch van Beijnum <iljitsch@muada.com>]

On Wed, 23 Oct 2002, Tony Hain wrote:

> > Actually holes in PA space is perfectly fine for the network, as you
> > can filter the more specifics and still have connectivity.

> This statement is self contradictory.

How so?

> > However, it is not so great for the
> > organization using the addresses since this doesn't address
> > all failure modes.

> The point I was making about punching holes in PA is that the more
> influential organizations will get the full prefix routed globally.

So then the question becomes: how do we limit the growth in
organizational influentialness?  :-)

This is bad for operators as they have to make complex filters. Also,
this "solution" still requires renumbering.

> > This could be done by having several instances of
> > this address space and have two places that would otherwise
> > be aggregated together sit in a different instance. By
> > rotating the axes and limiting everything to (say) from -60
> > to +60 degrees you eliminate the pole problem.

> I played with rotating the axis, but the only thing that made Europe
> contiguous was to put the origin on a 22.5 degree mark.

That would be shifting. What I mean is have at least three instances,
one with the poles at 90 north/south, one with the "poles" at the
equator at the 0 and 180 meridians and one with the poles at the
equator at the 90 and 270 meridians. Then you only need to go upto 45
degrees and still every part of the world would be covered by two
instances. This means 1.5 times more address space used, but 2 times as
much usable in the non-polar regions.

> > Still, there is one unanswered question: what problem is solved by
> > having such a close relationship between geography and address space?

> I was not trying to force any particular alignment. The goals were:
> Uses current BGP protocol.
> Aggregate the basement-multi-homer, while recognizing the CNN's of the
> world will always get a full prefix announced.
> Decouple the scale of aggregation, so it becomes a regional decision.
> Make it simple to derive by basing it on a globally consistent
> reference.

You fail to address my question. This scheme uses an incredible amount
of address space, but still manages to come up short in very densely
populated areas. The aggregation properties are relatively poor. So what
is it that makes all these downsides worth it?

Basing a geographical address allocation scheme on population (x
addresses per person) rather than geography (x addresses per square
kilometer) makes more sense, as long as you're not going to use IP
addresses to aim your microwave antenna or something like that.