kooky BGP tricks

Greetings all,

Time for the "kooky routing idea of the year" post...

Scenario:

AS65000 is a bandwidth provider. One of their downstreams wishes
to peer with AS65100, or to multihome with AS65100 as a second
upstream. The obvious and 100% correct answer is for $downstream
to register their own ASN, that anyone ready to multihome or peer
can afford $500 up front and a few bucks per year. We all know
this.

However, $downstream wishes to advertise the routes without
registering an ASN. AS65100 decides to advertise $downstream's
prefixes as

  65100 65000 ?

exactly as if 65000 were sending only $downstream's routes to
65100. From a technical perspective, this works. Yes, there are
issues with more-specifics and perhaps loop detection.

The question:

What would your reaction be if you were AS65000? Note that this
is a political/admin question, _not_ a technical one.

My thoughts:

From an administrative perspective, this can get messy, but is

doable iff 65000 and 65100 agree in advance. The IP space analog
is done routinely.

I'd not mind being either 65000 or 65100 -- _iff_ both ASNs
agreed in advance. Cutting down on leaf ASNs without causing
inconsistent ASNs seems like a reasonable goal.

Wrapping self in flameproof insulation...

Eddy