[address-policy-wg] Re: [ppml] [GLOBAL-V6] Re: Just say *NO* to PI space -- or how to make it less destructive

"Stephen Sprunk" <stephen at sprunk.org> writes:

> ARIN has replied to me privately that two IPv6 tunnels over the same 
> physical link count as "multihoming"; another PPML poster has told me 
> privately he's actually gotten an ASN that way.
>
> IMHO this needs to be corrected, but it doesn't appear to be abused except 
> out of novelty, so it's not a dire emergency.

Now, this is an interesting one.  Where would you draw the line for
diversity of connections being truly "multihomed"? Here are a few
scenarios for your consideration:

   Commodity MPLS from a third party provider (yes, i know this doesn't
   exist yet) with one pipe going to two ISPs.

   Commodity Frame Relay or ATM with two DAFs entering the facility, but
   an inspection of the DLRs for the PVCs shows that they both traverse
   the same switch.

   Two SONET connections that are groomed onto the same OC48.

   Two SONET connections that are physically distinct but enter the
   customer facility via the same conduit.

I'm not so sure that I agree with your implication that justifying an
ASN on the basis of two tunnels is "abuse".  It might be "poor
engineering", "unwise", or "certainly something I would never do", but
ARIN policy is intended to apply good stewardship principles, not
coerce people's business or engineering plans.  We agree that the
current level of unconventional registration is likely low.  I don't
agree that there's anything to "fix" here.

By the way, the other way you can justify an ASN is to have a "unique
routing policy".  What that constitutes is left as an exercise to the
reader, but I'm sure that a session in the bar in St. Louis could come
up with some really freaky scenarios.

Current policy is OK by me.  It will be even more OK after 32-bit ASNs
are the norm.

                                        ---Rob