[115471] in North American Network Operators' Group
Use of Default in the DFZ: banned in philly, see it now on the net!
daemon@ATHENA.MIT.EDU (Randy Bush)
Tue Jun 23 15:52:43 2009
Date: Tue, 23 Jun 2009 12:51:01 -0700
From: Randy Bush <randy@psg.com>
To: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
due to nanog pc silliness, my lightning talk on $subject was not given
in philly. i had promised to report to nanog the results of our winter
experiment which used as path poisoning. here is the lightning talk i
would have given.
http://archive.psg.com/090615.nanog-default.pdf
this is really meant to be a talk, so the slides can be a bit hard.
on slide 6
/20 is the as path length of a /20, i.e. a 'normal' distribution,
as seen from bgp monitors at RV, RIS, and a jillion others
/25 is the as path length distribution we saw pinging from the /25
BGP is the as path length distribution we saw from RV/RIS
i.e. BGP views are significantly skewed. but most of us knew that.
on slides 10 and 11, the categories stub, small isp, large isp are from
a ucla study. imiho, you should take them with a grain of salt.
on 12, the reason for the funniness around 30 test points is because, we
really wanted >= 30 test points in an AS. so if we got close, we
scanned harder to find them.
please do check your as at <http://psg.com/default/> and then actually
look at your router config. i found one of my routers still had a
default from when i was bringing it up.
randy