This originally appeared on the routing-wg@ripe.net mailing list. I'd be
curious to hear what Juniper has to say about it.
-Hank
> Dear all,
>
> remembering the thread on "Route update stats" in December ?
>
> Specifically:
>
>http://www.ripe.net/ripe/mail-archives/routing-wg/2002/msg00050.html
>
> Now Christophe Belmont, GEANT-NOC, together with Juniper found a
> solution and we successfully tested it:
>
> They implemented "BGP Guard Time" (Cisco like 30 seconds) and the
> result was impressive:
>
> The number of BGP update messages received from GEANT dropped by ~85%
> and the number of "flaps" seen from GEANT by ~75% !
>
> BGP guard time (30sec) means that updates are only sent to neighbors for
> prefixes which have stayed in the routing table for 30 seconds. I'm
> sure you know the specific problem, that when a prefix is withdrawn in a
> meshed environment, lots of updates are sent from BGP entities which do
> think that they still have a (longer) path. It may take quite some time
> until all these false updates are dying down. Without this guard time a
> BGP speaker immediately forwards all those false updates to all peers.
> I guess that if you would globally disable BGP guard time (which
> fortunately is default ON=30seconds for Ciscos but apparently not for
> Junipers) quite some routers would collapse on these withdrawal
> aftermaths.
>
> So my suggestion would be for all ISPs using Juniper routers: turn on
> "BGP Guard Time" (Cisco like 30 seconds).
>
> Christophe, probably you can post the details to the list !?
>
> 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) ---
> ---
> ---------------------------------------------------------------------- ---
curious to hear what Juniper has to say about it.
-Hank
> Dear all,
>
> remembering the thread on "Route update stats" in December ?
>
> Specifically:
>
>http://www.ripe.net/ripe/mail-archives/routing-wg/2002/msg00050.html
>
> Now Christophe Belmont, GEANT-NOC, together with Juniper found a
> solution and we successfully tested it:
>
> They implemented "BGP Guard Time" (Cisco like 30 seconds) and the
> result was impressive:
>
> The number of BGP update messages received from GEANT dropped by ~85%
> and the number of "flaps" seen from GEANT by ~75% !
>
> BGP guard time (30sec) means that updates are only sent to neighbors for
> prefixes which have stayed in the routing table for 30 seconds. I'm
> sure you know the specific problem, that when a prefix is withdrawn in a
> meshed environment, lots of updates are sent from BGP entities which do
> think that they still have a (longer) path. It may take quite some time
> until all these false updates are dying down. Without this guard time a
> BGP speaker immediately forwards all those false updates to all peers.
> I guess that if you would globally disable BGP guard time (which
> fortunately is default ON=30seconds for Ciscos but apparently not for
> Junipers) quite some routers would collapse on these withdrawal
> aftermaths.
>
> So my suggestion would be for all ISPs using Juniper routers: turn on
> "BGP Guard Time" (Cisco like 30 seconds).
>
> Christophe, probably you can post the details to the list !?
>
> 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) ---
> ---
> ---------------------------------------------------------------------- ---