Brocade Communications Systems ICX 7250 series, Configuration Manual

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The reuse parameter specifies how low a penalty for a route must be before the route becomes eligible for use again, after being
suppressed. You can set the reuse threshold to a value from 1 through 20000. The default is 750 (0.75, or three-fourths, of the penalty
assessed for a one flap).
The suppress parameter specifies how high the penalty for a route can be before the device suppresses the route. You can set the
suppression threshold to a value from 1 through 20000. The default is 2000 (more than two flaps).
The max-suppress-time parameter specifies the maximum number of minutes that a route can be suppressed regardless of how
unstable it is. You can set the maximum suppression time to a value from 1 through 255 minutes. The default is 40 minutes.
This example shows how to change the dampening parameters.
device(config-bgp-router)# dampening 20 200 2500 40
This command changes the half-life to 20 minutes, the reuse threshold to 200, the suppression threshold to 2500, and the maximum
number of minutes a route can be dampened to 40.
NOTE
To change any of the parameters, you must specify all the parameters with the command. To want to leave any parameters
unchanged, enter their default values.
Using a route map to configure route flap dampening for a specific
neighbor
You can use a route map to configure route flap dampening for a specific neighbor by performing the following tasks:
• Configure an empty route map with no match or set clauses. This route map does not specify particular routes for dampening
but does allow you to enable dampening globally when you refer to this route map from within the BGP4 configuration level.
• Configure another route map that explicitly enables dampening. Use a set clause within the route map to enable dampening.
When you associate this route map with a specific neighbor, the route map enables dampening for all routes associated with the
neighbor. You also can use match clauses within the route map to selectively perform dampening on some routes from the
neighbor.
NOTE
You still need to configure the first route map to enable dampening globally. The second route map does not enable dampening
by itself; it just applies dampening to a neighbor.
• Apply the route map to the neighbor.
To enable route flap dampening for a specific BGP4 neighbor, enter commands such as the following.
device(config)# route-map DAMPENING_MAP_ENABLE permit 1
device(config-routemap DAMPENING_MAP_ENABLE)# exit
device(config)# route-map DAMPENING_MAP_NEIGHBOR_A permit 1
device(config-routemap DAMPENING_MAP_NEIGHBOR_A)# set dampening
device(config-routemap DAMPENING_MAP_NEIGHBOR_A)# exit
device(config)# router bgp
device(config-bgp)# dampening route-map DAMPENING_MAP_ENABLE
device(config-bgp)# neighbor 10.10.10.1 route-map in DAMPENING_MAP_NEIGHBOR_A
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.
Configuring route flap dampening
Brocade FastIron Layer 3 Routing Configuration Guide
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