Re: The SWAMP

[randy () psg com (Randy Bush)]

> My humble suggestion is forced non-local proxy aggregation. Where an
> aggregrate and more specifics are visible through the same next AS
> hop, the specific advertisements can be dropped without change in the
> the policy environment.

In the presence of multi-homing, this will create shorter prefixes visible
through the path which proxy-aggregates, thereby changing policy another hop
away and changing the load distribution.

This is similar to Sprint's aggregating multi-homed customer announcements
at Sprint's external borders.  They justify this with words about saving
prefixes, which might be credible if one did not look at the rest of what
they actually announce.  Rant, rave, foam, ...

> such a mechanism can yeld coarse outcomes which may not produce a precise
> match to desired traffic flow policy in all situations

I suspected you might have seen the problem.

> Here again the issue becomes a qualitative issue of whether its better to
> damp down the routing tables at the expense of close accuracy to express
> traffic flow preferences or to allow the tables to grow to ensure absolute
> integrity of traffic flow preferences across the entire Internet.

I suspect that we will get the major part of the win if folk clean up the
messes they are making today, and we can hold proxy aggregation in reserve
if that does not work.  I have hope that Tony will resume publishing, and
that will encourage some serious offenders to clean up their announcements.

randy
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