Re: ISP customer assignments

[William Herrin <herrin-nanog () dirtside com>]

On Mon, Oct 5, 2009 at 7:41 PM,  <Robert.E.VanOrmer () frb gov> wrote:
> The address space is daunting in scale as you have noted, but I don't see
> any lessons learned in address allocation between IPv6 and IPv4.

Robert,

I would suggest that some of the lessons we learned are faulty.
Maladaptive. CIDR for instance.

In a classful world, folks who needed a class A got a class A and were
able to announce a class A. They couldn't announce 4200 little
divisions of their addresses like Bell South on last Friday's CIDR
report. CIDR made today's BGP mess possible.

With a larger address space, let's say 128 bits, things *could* have
been partitioned in a such a way that there were enough class B's for
everyone who needed more than a class C and plenty of class-A's for
everyone who needed more than a class B.

There's no doubt that CIDR saved the Internet. There -weren't- enough
IPv4 class B's for everyone who needed more than a class C. CIDR made
it possible to express ranges of class C's as a single route and
that's just the start. But CIDR also created today's problems where it
isn't possible to tell the difference between a route that represents
a unique multihomed endpoint and routes which reflect nothing more
than a bad actor making you pay his traffic engineering cost.

So now Verizon is in open revolt against ARIN. They positively refuse
to carry /48's from legitimately multihomed users. Eff 'em. Perhaps
Verizon would sooner see IPv6 go down in flames than see their TCAMs
fill up again. Who knows their reasoning?

Agree or disagree, it is indeed food for thought. One thing I can say
with confidence: as a community we truly haven't grasped the major
implications of an address space that isn't scarce coupled with a
routing table that is.

Regards,
Bill Herrin


-- 
William D. Herrin ................ herrin () dirtside com  bill () herrin us
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