I'll take a stab at it since nobody else did. Oliver Hensel wrote: > > Hi! > > Can someone point me to a document which explains > what happens with a prefix that is dampened if > it's distributed via two providers.
I don't think you'll find a document that answers the question explicitly because the implicit answer is sort of obvious, as I think you realize. It's a route that's dampened, not a prefix. With two providers, in most cases, there would be two distinct routes to your prefix. A BGP route has path attributes including an AS_Path, which is a list of Autonomous System numbers. With two providers, the two routes will be distinct and have a different set of AS numbers in most situations. Otherwise what would be the point? > > Will only the penalized route dampened, that is > will we still have connectivity if one link is > flapping. I think so, but I'd like to have some > confirmation for that. If just one of your links is flapping, then just one of your routes will get dampened. The other one will still be usable. If your two links share a circuit to the telco or physically share a path that has been dug up by the proverbial back-hoe operator, it's possible both links could be flapping, and then they will both get dampened, but hopefully you have a network design that avoids that problem. Don't let BGP rain on your parade and dampen too much at once! Have good physical diversity. ;-) Priscilla > > Thanks and best regards, > > Oliver > > > -- > Oliver Hensel > telematis Netzwerke GmbH > mailto: [EMAIL PROTECTED] > Siemensstrasse 23, D-76275 Ettlingen > Tel: +49 (0) 7243-3448-0, Fax: -498 > visit us: http://telematis.com > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=65120&t=65086 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
