BGP Route Dampening

Route Dampening is a way to suppress flapping routes instead of being advertised.  An unstable network can cause BGP routes to flap, which can cause other BGP routers in the network to constantly reconverge.

• Penalty: An incremented numeric value that is assigned to a route each time it flaps.

• Half life time: A configurable numeric value that describes the amount of time that must elapse to reduce the penalty by one half.

• Suppress limit: A numeric value that is compared with the penalty.  If the penalty is greater than the suppress limit, the route is suppressed.

• Reuse limit: A configurable numeric value that is compared with the penalty.  If the penalty is less than the reuse limit, a suppressed route that is up will no longer be suppressed.

• Max suppress limit: The longest amount of time that a route can be suppressed.

BGP Route Dampening is disabled by default. It can be enabled by following command (if configured with no optional parameters, the default value applies )

router bgp 65010
 bgp dampening 

RB#show ip bgp dampened-paths
BGP table version is 120, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          From             Reuse    Path
*d 10.2.0.0/8       2.2.2.2          00:21:00 10 iCode language: PHP (php)

Reference: Cisco