a crude method of limiting long-prefix propagation

[mccreary at pch.net]

You wrote:
>http://www.automagic.org/~jabley/draft-jabley-edge-policy-propagation-control-
>00.txt
>
>This is something that came out of a couple of conversations in the bar.
>Hopefully I captured some of the salient points before the vodka kicked
>in.
>
>I thought this might qualify as a possible short-term measure to reduce
>prefix bloat, hence ptomaine.

With a small change in semantics, it seems like this scheme is sufficient to
support restricted announcement of any route to an explicit set of ASes.  Just
change the meaning of EPPC_ALOW:ASN a little so it indicates `advertiseable
to', so that a participating AS will only advertise this route to a peer if
the proper community attribute appears in the route.

This scheme has the disadvantage that it requires all ASes in the region to
support this method for indicating a scoped advertisement, rather than just
those immediately adjacent to the origin AS.  However, it also adds the
ability to support arbitrarily shaped regions for limited distribution of
specifics.

The real question is whether any ISP thinks this is compatible with their
current traffic engineering efforts.  Any solution requiring significant
amounts of inter-provider cooperation will need to demonstrate clear benefits
for all parties involved, and I can't think of a compelling reason why an
AS 2 or more hops from the origin AS would want to support remote manipulation
of their transit traffic (in the general case, at least).
--
Sean McCreary                                                 mccreary at pch.net