Re: BGP Dampening question
<<<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 . <<<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 - You start. We finish.
-----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_feat... | <<<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-----
participants (2)
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Bruce Pinsky -
D Train