Brocade TurboIron 24X Series Configuration Guide - Manual (Page 759)

Brocade TurboIron 24X Series Configuration Guide 725
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Configuring route flap dampening
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 statements. 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 BGP configuration level.
• Configure another route map that explicitly enables dampening. Use a set statement 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 statements 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.
TurboIron(config)#route-map DAMPENING_MAP_ENABLE permit 1
TurboIron(config-routemap DAMPENING_MAP_ENABLE)#exit
TurboIron(config)#route-map DAMPENING_MAP_NEIGHBOR_A permit 1
TurboIron(config-routemap DAMPENING_MAP_NEIGHBOR_A)#set dampening
TurboIron(config-routemap DAMPENING_MAP_NEIGHBOR_A)#exit
TurboIron(config)#router bgp
TurboIron(config-bgp-router)#dampening route-map DAMPENING_MAP_ENABLE
TurboIron(config-bgp-router)#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 statements. At the BGP 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 statement. The route map implicitly applies to
all routes. Since the route map will be applied to a neighbor at the BGP 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 statements
for specific routes, the route map enables dampening for all routes received from the neighbor.