RE: BellSouth prefix deaggregation (was: as6198 aggregation event)

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1

IMHO, I think we should create a route-set obj like call
it... RS-DEAGGREGATES and list all the major irresponsible
providers's specific /24's in it...

CASE: Business has a /24 from X provider in order to multihome.
That /24 is de-aggregated from a /19, with this policy that
/24 may not be routed.

possible exception: When 2002-3 get passed by ARIN, this could even take
on new meaning. ARIN says they will use a single /8 for the handing
out of /22-/24 for multihoming end users. will you then filter those
/24's also?

Also:
What happens when that /24 for Business Y noted above is dual routed
by ISP A and ISP B, and ISP A's upstream filters but ISP B's does not?
Will there be asymmetric routing?

Finally:
Can anyone from BellSouth, explain the end goal of the de-aggregation?

I suspect with 40 + ASs they may be rebuilding their network with a
recently announced list of new IP services and DSL growth as asked for
under the Federal government Rural DSL regulations... (I'm not trying to defend
them, just giving some possibilities)

2

The idea is to not filter just /24's.

The idea is to work with people who run cidr-report.org (may be.. or other people who are willing to coop), and find an ASNs who advertise a lots of irresponsible deaggregates.

As you can see, cidr-report only shows deaggregation for the prefixes that an AS _specifically_ _originates_. It does not show /24's out of downstream ASes, so it is safe.

Basically there would need to be some sort of monitoring process to review the cidr-report regularly to keep a close watch on irresponsible providers, and generate route-set filter against them until they aggregate themselves.

-hc