Date: Wed, 18 Sep 2002 09:09:51 -0400 From: Zhuoqing Morley Mao <zmao@research.att.com>

Could you elaborate on the phenonmeon you observed? In particular, how were you able to determine it was caused by the BGP convergence effects?

Hi Morley, we (ACOnet/AS1853) do have our primary transit through Sprint/AS1239 and a (lowerpref) backup through Geant/AS20965_3549. We are receiving a full table from both (on two different routers). The path through Sprint for most of the US Internet is shorter than through Geant. When comparing the flap statistics on the two routers many of the listed prefixes are the same with about the same "duration", but the number of flaps seen through the longer path is much bigger (factor of 2-3 !) As I wrote in a previous mail, feel free to use our looking-glass http://www.aco.net/lookingglass/lg.html [flap statistics] to see the enormous amount of flaps counted by our Geant connected router. Unfortunately our Sprint connected router is not accessible through the looking-glass. But if you like I could produce snapshots and send them to you.

We hope that someone in Europe could also help out with the experiment, details of which are described at http://www.psg.com/~zmao

I think there was the idea to eventually enable RIS boxes as BGP beacons ? We do have a RIPE RIS box in Vienna at the VIX (RRC05).

We currently have two beacons in the U.S., some topology diversity would really help.

If RIS doesn't help we are considering setting up an ACOnet beacon for you, however this might not happen before begin of October.

Thanks!

You are welcome ! Kind regards CP --- ---------------------------------------------------------------------- --- --- Christian Panigl : Vienna University Computer Center - ACOnet --- --- VUCC - ACOnet - VIX : -------------------------------------------- --- --- Universitaetsstrasse 7 : Mail: Panigl@CC.UniVie.ac.at (CP8-RIPE) --- --- A-1010 Vienna / Austria : Tel: +43 1 4277-14032 (Fax: -9140) --- --- ---------------------------------------------------------------------- ---