The Gorgon's Knot. Was: Re: Verio Peering Question

Sat Sep 29 03:01:27 UTC 2001

Here we go again, but isolated and clearly this time:

> Sprint had valid reasons for filtering.  ...
             ^^^^^

Oh yeah?  Did they think so?  Who else has any voice in whether their
reasons were valid?  Frankly my dear, if Sprint or any other provider
wanted to filter all prefixes containing an odd number of bits, and if they
thought they had a valid reason for doing so, then by definition, their
reasons would be valid.  *Our* opinion of the validity (or not) of their
reasons would be *irrelevant*.

MIBH used to run with prefix filters.  It didn't stop much but what it did
stop was worthless -- not just people chopping up their ARIN blocks, people
doing cheap distributed load balancing by emitting a prefix from multiple
locations as a way to do cheap distributed load balancing(*), but erroneous
garbage that never should have been there, and so, wasn't.  At least in our
view of the net.  Our customers were happy, so, so were we.

(*) if you want to do cheap distributed load balancing by faking multihoming
of a prefix, you'll need swamp space, which seems like a small fence to climb.