nanog mailing list archives

Re: /19 addresses and redundancy


From: Jeremy Porter <jerry () fc net>
Date: Tue, 11 Nov 1997 11:34:08 -0600


In message <yt4t5j8sh9.fsf () cesium clock org>, "Sean M. Doran" writes:
Phil Howard <phil () charon milepost com> writes:

Route filtering is not the end of the world.

Wow.  Times have changed.

You also need to make sure that the ISPs do not filter routes for parts
of their own blocks coming in from other peers.  If ISP-A did such filtering
,
then their own customers will find you unreachable, as well as those in ISP-
C
if ISP-C sends traffic for you into ISP-A.

I know of no ISPs doing such a thing

Sprintlink did at one point.  It's a really good idea to do
this in general because it mitigates the disconnectivity
customers assigned prefixes out of one's address blocks
will suffer if and when someone accidentally(?) announces
subnet of those blocks.

Inbound filters can be adjusted, you know.  Unfortunately
the people who have inbound filters have never figured out
that they should make this a service that they charge for.

However, since inbound announcement filtering is a game
anyone can play, I recommend people consider the
implications of fee-based filter updating and how it can
effect their routing whether or not they are the ones
doing the inbound filtering.

Connectivity = bidirectional bandwidth + bidirectional reachability.

Connectivity = value.

      Sean.

Since you would need some type of settlement system in order for
this to work, if you could get a third party to maintain the access
lists information, and manage the settlements, then you might have something.
I.e. a third part, Neutral Settlement Authority (NSA), uses a database
such as the IRR to maintain a set of policy statements, that are readable
by the rest of the Internet,  They convince a few providers, say
Sprint and Digex, to listen to them for prefix length filter exceptions,
in return this Neutral Settlement Agency, pays these providers for this
service.  The Neutral Settlement Agency then, posts to Nanog, or
other lists, saying it will cost you X dollars to have your execption listed
with us at some cost of what the costs to providers A and B are paid plus
some percentage for profit.

Looking at this, pretty much any BGP speaking peer at the MAE could do
it with the correct configurations, and the RA service could do it also,
although there are those that won't touch an RS with a 10 AS BGP path
extension, although perhaps if they were getting paid for it...

The biggest problem I see with prefix charging is the many to many
contract nature, which is where a MLPA type situtation is helpful,
but must be setup so that different providers can negotiate different
rates, as network sizes differ, and the cost to carry those prefixes
internally varies.



---
Jeremy Porter, Freeside Communications, Inc.      jerry () fc net
PO BOX 80315 Austin, Tx 78708  |  1-800-968-8750  |  512-458-9810
http://www.fc.net


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