Re: comments on draft-py-multi6-gapi-00.txt

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

On Wed, 5 Feb 2003, Joe Abley wrote:

> > Without pre-allocation there can't be any successful aggregation. We
> > can see this in IPv4 today: the RIRs (pre-) allocate blocks that are too
> > small to ISPs so these ISPs end up with lots of relatively small
> > blocks.

> Organisations move, merge and split apart. Physical and layer-2
> networks can change radically with no impact on layer 3. There are
> operators today selling wide-area layer-2 transport services in which
> single subnets span continents. Layer-3 topologies (both intra-AS and
> inter-AS) change on a daily basis.

People keep themselves busy. So?

> Given such a turbulent soup of connectedness, what criteria for
> pre-allocation of routing names stands a chance of not being
> out-of-date as soon as it is published?

Let's take the speed of light for this. You can change many things about
your network, but not the fact that making packets take a 10000 km
detour adds a 50 ms delay. Also, if you're going to physically move your
network renumbering is only a minor extra task in addition to everything
else that's going on.

> [There was no pre-allocation with IPv4, and there is certainly *some*
> successful aggregation today, despite what you say, and even given the
> allocation issues you mention.]

ISPs get /19s, /20s and /16s because it is assumed they'll need more in
the future than the single /24 they're requesting today. This is what I
mean by pre-allocation.