Subject: bgp pruning

From: "Natale, Jonathan" <[email-masked]>
Date: Thu, 6 Jun 2002 13:55:31 -0400

Given the following config:

DUT-------r2

l         l

l         l

l         l

r3--------r4

All routers are in different AS's.  The AS # is the router #.  r3 showed
that the DUT was sending the routes that originated from r3 with an AS path
of 3 4 2 1 (which is the correct AS path).  The expected behavior is for the
DUT to not send these routes since they will be denied by r3 anyway as part
of the BGP pruning process; this is what a major vendor does (prunes on the
output as well). But the RFC1771 does not require that these routes not be
sent (it does require that they be pruned at the input of r3).  It seems to
me that it IS better to do it the way the major vendor does it (prune at
input and output) in order to save BW and processing.

Why does RFC1771/the 17th draft not specify output pruning (or does it)?  

Can/should this be added?

What does that other major vendor do?

How am I doing on my political correctness?

Thank you.