Cisco Systems 78-11741-02 manual Monitoring and Maintaining BGP Route Dampening, IPC-330

Configuring BGP

Configuring Advanced BGP Features

To change the default values of various dampening factors, use the following command in address family or router configuration mode:

Command	Purpose
Router(config)# bgp dampening half-life reuse	Changes the default values of route dampening factors.
suppress max-suppress [route-mapmap-name]

Monitoring and Maintaining BGP Route Dampening

You can monitor the flaps of all the paths that are flapping. The statistics will be deleted once the route is not suppressed and is stable for at least one half-life. To display flap statistics, use the following commands in EXEC mode as needed:

Command	Purpose
Router# show ip bgp flap-statistics	Displays BGP flap statistics for all paths.
Router# show ip bgp flap-statistics regexp regexp	Displays BGP flap statistics for all paths that match the
	regular expression.
Router# show ip bgp flap-statistics filter-list	Displays BGP flap statistics for all paths that pass the filter.
access-list
Router# show ip bgp flap-statistics ip-address mask	Displays BGP flap statistics for a single entry.
Router# show ip bgp flap-statistics ip-address mask	Displays BGP flap statistics for more specific entries.
longer-prefix
To clear BGP flap statistics (thus making it less likely that the route will be dampened), use the following
commands in EXEC mode as needed:
Command	Purpose
Router# clear ip bgp flap-statistics	Clears BGP flap statistics for all routes.
Router# clear ip bgp flap-statistics regexp regexp	Clears BGP flap statistics for all paths that match the regular
	expression.
Router# clear ip bgp flap-statistics filter-list	Clears BGP flap statistics for all paths that pass the filter.
list
Router# clear ip bgp flap-statistics ip-address mask	Clears BGP flap statistics for a single entry.
Router# clear ip bgp ip-addressflap-statistics	Clears BGP flap statistics for all paths from a neighbor.

Note The flap statistics for a route are also cleared when a BGP peer is reset. Although the reset withdraws the route, there is no penalty applied in this instance, even if route flap dampening is enabled.

Cisco IOS IP Configuration Guide

IPC-330