[arin-ppml] IPv6 Non-connected networks

William Herrin bill at herrin.us
Thu Feb 4 20:13:58 EST 2010

On Thu, Feb 4, 2010 at 7:21 PM, Barbara Roseman
<barbara.roseman at icann.org> wrote:
> I think that's a fair restatement of what I was saying,
>except you left out the part about uniqueness vs.
>routeability. My points were twofold:
> 1) ARIN can only offer unique registration of IP
>addresses, they cannot offer unique use of
>addresses -- nor can anyone else because
>Bad People tend to ignore the rules, and Ignorant
>People are, well, ignorant.

Hi Barbara,

Okay. That reads as a reasonable statement to me. I don't follow how
it bears on the routing policy issue.

Or at least I don't see a way that ARIN could alter its process to
make announcements inconsistent with the ARIN registrations easily
filterable. If such a thing was possible, I'd surely want to see an
ARIN policy proposal as, no doubt, would every ISP on the planet.

> 2) The ARIN community and the NANOG community
>have discussed repeatedly that it's not simple cause
>and effect from ARIN's allocation/assignment policies
>to operator's routing policies, though the influence is
>extreme. If the connectivity provider is large enough,
>as CJ notes, than they can do whatever they want.

Okay. So because providers are already able, for a time, to make
unreasonable choices which defy the defacto standards adopted by the
overwhelming majority of their peers we should not adopt practices
that enable more flexibility within the set of -reasonable- choices? I
don't follow.

On Thu, Feb 4, 2010 at 7:09 PM, cja at daydream.com <packetgrrl at gmail.com> wrote:
> Bill,
> I see what you're saying here but the reality for me was that for close to a
> year a very large ISP didn't pay attention to ARIN's allocation of parts of
>  They were big and I was little and so they won at least for a
> time.

That's disappointing in this day and age, but then we're talking about
the same folks who thought their customers wouldn't cry bloody murder
when they cut off communications with cogent. If you ever have
problems with them carrying your routes again, drop me a line so I can
start claiming service credits. That'll get their attention. :)

> ARIN has no control over filtering/routing policies.  At a recent NANOG
> there was a panel where ISPs in no uncertain terms told the community that
> they do not want ARIN policies to include anything about routing policy.  I
> believe at this point that most of the RIRs have removed routing criteria
> from their IPv6 policies for that very reason.

Hi Cathy,

Poor control is not the same as no control and getting ARIN policy out
of the way of ISPs setting routing policy is not the same as saying
and doing nothing about routing policy.

In a very real sense, addressing is routing is addressing. Each
follows from the structure of the other. An addressing policy which
does not impact routing policy is simply inconsistent with reality.

I'll repeat that for emphasis: There's no such thing as addressing
policy which does not impact routing policy. It can't exist.

Thus the choices are:

1. Create an addressing policy which implicitly shapes routing policy
through the accidents of its structure.

2. Create an addressing policy which is informed by and explicitly
shapes a uniform routing policy.

3. Create an addressing policy which is an enabler for a broad range
of rational routing policies and let the overall routing policy find
its own equilibrium.

What we do now is sometimes #1 and sometimes #2. For example:

A. The unfilterability of traffic engineering is an accidental
side-effect of CIDR address allocations. Because they're all mashed
together in the same pool, operators can't tell the difference between
easily filterable TE and unfilterable multihomed downstreams.

B. Accepting /24 reassignments to multihomed customers regardless of
size is informed by the /24 boundary present in DFZ routing policy.

C. CIDR allocation (instead of simply assigning a linear range of
addresses) is an explicit attempt to bring about aggregation within
the routing system. It's routing policy directly encoded as addressing

I think we'd be wiser to pursue course #3: enable a broad range of
sensible routing policies and then step back out of the way.

Bill Herrin

William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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