Re: Route Flap Damping: Harmful ?

["Christian Panigl, ACOnet/VIX/UniVie" <]

>Date: Wed, 18 Sep 2002 09:09:51 -0400
>From: Zhuoqing Morley Mao zmao@localhost
>
>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

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