Route Supression Problem

Wed Mar 12 21:28:50 UTC 2003


From: "Iljitsch van Beijnum"

> > Nope.  It's per-prefix.
>
> If that is the case then dampening is severely broken, because then a
> router that receives a prefix over two paths will lose *both* if _one_
> flaps.
>
Which makes me wonder what happens when one of my BGP peers is flapping and
the other is holding stable with an AS prepend on it.

> In any case, it is done on the eBGP router receiving the prefix/route,
> so unless the two ISPs in question peer using the same router as they
> use to connect to Jack's AS, there still shouldn't be any flapping
> multiplication. (Hm, unless that happened inside Jack's network...?)
>
My network is too simplistic to have flapping multiplication. The only
difference between the customers routes and my own are that I do an AS
prepend on all my networks going out to one of my peers so that the peer
only sends customer traffic to me and serves as a last resort, while my
customers routes out all peers without modification.

-Jack