Brocade Communications Systems FastIron SX 1600, Configuration Manual, Page: 426 / 593

In this example, the first command globally enables route flap dampening. This route map does not contain any match or set clauses. At
the BGP4 configuration level, the
dampening route-map command refers to the DAMPENING_MAP_ENABLE route map created by
the first command, thus enabling dampening globally.
The third and fourth commands configure a second route map that explicitly enables dampening. Notice that the route map does not
contain a match clause. The route map implicitly applies to all routes. Since the route map will be applied to a neighbor at the BGP4
configuration level, the route map will apply to all routes associated with the neighbor.
Although the second route map enables dampening, the first route map is still required. The second route map enables dampening for
the neighbors to which the route map is applied. However, unless dampening is already enabled globally by the first route map, the
second route map has no effect.
The last two commands apply the route maps. The dampening route-map command applies the first route map, which enables
dampening globally. The neighbor command applies the second route map to neighbor 10.10.10.1. Since the second route map does
not contain match clauses for specific routes, the route map enables dampening for all routes received from the neighbor.
Removing route dampening from a route
You can un-suppress routes by removing route flap dampening from the routes. The device allows you to un-suppress all routes at once
or un-suppress individual routes.
To un-suppress all the suppressed routes, enter the following command at the Privileged EXEC level of the CLI.
device# clear ip bgp dampening
Syntax: clear ip bgp dampening [ ip-addr ip-mask ]
The ip-addr parameter specifies a particular network.
The ip-mask parameter specifies the network mask.
To un-suppress a specific route, enter a command such as the following.
device# clear ip bgp dampening 10.157.22.0 255.255.255.0
This command un-suppresses only the routes for network 10.157.22.0/24.
Displaying and clearing route flap dampening statistics
The software provides many options for displaying and clearing route flap statistics.
Displaying route flap dampening statistics
To display route dampening statistics or all the dampened routes, enter the following command at any CLI level.
device# show ip bgp flap-statistics
Total number of flapping routes: 414
Status Code >:best d:damped h:history *:valid
Network From Flaps Since Reuse Path
h> 10.50.206.0/23 10.90.213.77 1 0 :0 :13 0 :0 :0 65001 4355 1 701
h> 10.255.192.0/20 10.90.213.77 1 0 :0 :13 0 :0 :0 65001 4355 1 7018
h> 10.252.165.0/24 10.90.213.77 1 0 :0 :13 0 :0 :0 65001 4355 1 7018
h> 10.50.208.0/23 10.90.213.77 1 0 :0 :13 0 :0 :0 65001 4355 1 701
h> 10.33.0.0/16 10.90.213.77 1 0 :0 :13 0 :0 :0 65001 4355 1 701
*> 10.17.220.0/24 10.90.213.77 1 0 :1 :4 0 :0 :0 65001 4355 701 62
Syntax: show ip bgp flap-statistics [ regular-expression regular-expression | address mask [ longer-prefixes ] | neighbor ip-addr ] as-
path-filter num
Configuring route flap dampening
FastIron Ethernet Switch Layer 3 Routing
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