Route flap dampening

To maintain scalability of a routed internet, it is necessary to reduce the amount of change in routing state propagated by BGP in order to limit processing requirements. The primary contributors of processing load resulting from BGP updates are the BGP decision process and adding and removing forwarding entries.

A route flap occurs when the state of a route changes from up to down or down to up. When a route state changes, the route tables of the devices that support the route also change. Route flap dampening prevents BGP from selecting unstable routes. If an EBGP peer goes down after you configure this feature, routes coming from the peer are dampened but not deleted.


This feature applies to EBGP routes but not IBGP routes.