Max Prefixes Configured on Customer BGP

Fri Aug 16 04:09:15 UTC 2002

On Thu, 15 Aug 2002, Richard A Steenbergen wrote:

> A better system might be where the session is kept up (or periodically
> polled, if you want to make it obvious to the other party that there is a
> problem) without installing the routes, and kept in a "quarantine" state
> for X amount of time to make sure that things stay below a configured
> number. This would be at least a slightly better way of recovering quickly
> once the "problem" has passed, without mucking things up every 15 minutes
> in the process.

Couldn't you do this with route-dampening?

So the first leak will of course be propagated before the max-prefix
takes effect. But once these routes are withdrawn, this should
create entries in the history table for these prefixes.

Depending on your dampening parameters, you should be able to configure
selective ASes to have very low tolerance for dampening, if you don't
already have a low tolerance for dampening.... Once the BGP session is
activated and if the offending prefixes reappear and trigger the
max-prefix threshold and are then withdrawn again, BGP dampening should
dampen the routes for 45 minutes or X, depending on your maximum
suppression value........

That X minutes should hopefully be enough time for customer to solve
problem, or for the ISP NOC to get on the phone with the customer.

While this still propagates the leaked routes at least twice, it does
prevent the routes from being constantly propagated every 15 minutes....

Please correct me if I'm wrong......The BGP Dampening route-map feature is
new to me. ;>

Regards,

Joe