Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 206

To configure route flap dampening parameters, set dampening parameters using a route map, clear information on route dampening and return suppressed routes to active state, view statistics on route flapping, or change the path selection from the default mode (deterministic) to non-deterministic, use the following commands. • Enable route dampening. CONFIG-ROUTER-BGP mode bgp dampening [half-life | reuse | suppress max-suppress-time] [route-map map-name] Enter the following optional parameters to configure route dampening parameters: - half-life: the range is from 1 to 45. Number of minutes after which the Penalty is decreased. After the router assigns a Penalty of 1024 to a route, the Penalty is decreased by half after the half-life period expires. The default is 15 minutes. - reuse: the range is from 1 to 20000. This number is compared to the flapping route's Penalty value. If the Penalty value is less than the reuse value, the flapping route is once again advertised (or no longer suppressed). Withdrawn routes are removed from history state. The default is 750. - suppress: the range is from 1 to 20000. This number is compared to the flapping route's Penalty value. If the Penalty value is greater than the suppress value, the flapping route is no longer advertised (that is, it is suppressed). The default is 2000.) - max-suppress-time: the range is from 1 to 255. The maximum number of minutes a route can be suppressed. The default is four times the half-life value. The default is 60 minutes. - route-map map-name: name of a configured route map. Only match commands in the configured route map are supported. Use this parameter to apply route dampening to selective routes. • Enter the following optional parameters to configure route dampening. CONFIG-ROUTE-MAP mode set dampening half-life reuse suppress max-suppress-time - half-life: the range is from 1 to 45. Number of minutes after which the Penalty is decreased. After the router assigns a Penalty of 1024 to a route, the Penalty is decreased by half after the half-life period expires. The default is 15 minutes. - reuse: the range is from 1 to 20000. This number is compared to the flapping route's Penalty value. If the Penalty value is less than the reuse value, the flapping route is once again advertised (or no longer suppressed). The default is 750. - suppress: the range is from 1 to 20000. This number is compared to the flapping route's Penalty value. If the Penalty value is greater than the suppress value, the flapping route is no longer advertised (that is, it is suppressed). The default is 2000. - max-suppress-time: the range is from 1 to 255. The maximum number of minutes a route can be suppressed. The default is four times the half-life value. The default is 60 minutes. • Clear all information or only information on a specific route. EXEC Privilege clear ip bgp dampening [ip-address mask] • View all flap statistics or for specific routes meeting the following criteria. EXEC or EXEC Privilege mode show ip bgp flap-statistics [ip-address [mask]] [filter-list as-path-name] [regexp regularexpression] - ip-address [mask]: enter the IP address and mask. - filter-list as-path-name: enter the name of an AS-PATH ACL. - regexp regular-expression: enter a regular express to match on. By default, the path selection is deterministic, that is, paths are compared irrespective of the order of their arrival. You can change the path selection method to non-deterministic, that is, paths are compared in the order in which they arrived (starting with the most recent). Furthermore, in non-deterministic mode, the software may not compare MED attributes though the paths are from the same AS. • Change the best path selection method to non-deterministic. Change the best path selection method to non-deterministic. CONFIG-ROUTER-BGP mode Border Gateway Protocol IPv4 (BGPv4) 206