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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: BGP Dampening question
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 D Train wrote: | <<<If A is flapping THAT much, time to get another provider, or another | local loop. If it <<<only flaps occasionally, not a big deal, the | routers will handle it. | | It isn't so much that one of our links are flapping all of the time, but | in our enterprise we have over 1000 locations, which can be 10 or 15 | circuits flapping at one given time. This is more for | management/administration reasons, other than just wheather or not the | router can with stand the torture. Each location is its own AS, and we | are running EBGP between all of our ASs, internally inside our global | AS, if that makes sense. If it were just a couple of cirucits dying on | us, that would be fine, but we are trying to come up with some sort of | dynamic solution so if our primary circuit is flapping, we won't be | flopping back in forth, from our primary to our secondary, from BGP | routes, to default route, and vice-versa, keeping our network stable . | Have you considered IP Event Dampening? http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1829/products_feature_guide09186a00800ad25b.html | <<<That said, I would not use flap dampening for this. | | If you don't recommend BGP dampening to fix our problem, what else is | there, that I have not found or thought of yet. Is there a true dynamic | solution to our problem? | | <<<yes, you can do what you want with flap dampening. Your router will | penalize the <<<announcements from A for every time it flaps, and will | wait until it has stopped <<<flapping for a user definable time before | sending packets to A again. | | So you could still use dampening successfully, even though the bgp | session keeps resetting. Does your peering session have to remain | stable, with you just dampening some routes, or can your session keep | bouncing, and it will still know to store these routes in either their | history state, or dampening state? | | D- | | ------------------------------------------------------------------------ | Do you Yahoo!? | Yahoo! Mail Address AutoComplete | <http://us.rd.yahoo.com/mail_us/taglines/aac/*http://promotions.yahoo.com/new_mail/static/ease.html> | - You start. We finish. - -- ========= bep -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.2 (MingW32) iD8DBQFA/ViAE1XcgMgrtyYRAstxAKDDA87duQEKntO5TE7KMNq5J5e0ngCgrqhe QtGQ0yf62GlI+T1Aq4yTWX4= =7VWA -----END PGP SIGNATURE-----
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