Brocade BigIron RX Series Configuration Guide - Manual (Page 967)

BigIron RX Series Configuration Guide 889
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Filtering
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The address-filter commands in this example configure two BGP4 address filters, for networks
209.157.22.0 and 209.157.23.0. The first route-map command creates an entry in a route map
called “DAMPENING_MAP”. Within this entry of the route map, the match command matches
based on address filter 9, and the set command sets the dampening parameters for the route that
matches. Thus, for BGP4 routes to 209.157.22.0, the device uses the route map to set the
dampening parameters. These parameters override the globally configured dampening
parameters.
The commands for the second entry in the route map (instance 10 in this example) perform the
same functions for route 209.157.23.0. Notice that the dampening parameters are different for
each route.
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.
BigIron RX(config)# route-map DAMPENING_MAP_ENABLE permit 1
BigIron RX(config-routemap DAMPENING_MAP_ENABLE)# exit
BigIron RX(config)# route-map DAMPENING_MAP_NEIGHBOR_A permit 1
BigIron RX(config-routemap DAMPENING_MAP_NEIGHBOR_A)# set dampening
BigIron RX(config)# router bgp
BigIron RX(config-bgp)# address-filter 9 permit 209.157.22.0 255.255.255.0
255.255.255.0 255.255.255.0
BigIron RX(config-bgp)# address-filter 10 permit 209.157.23.0 255.255.255.0
255.255.255.0 255.255.255.0
BigIron RX(config-bgp)# exit
BigIron RX(config)# route-map DAMPENING_MAP permit 9
BigIron RX(config-routemap DAMPENING_MAP)# match address-filters 9
BigIron RX(config-routemap DAMPENING_MAP)# set dampening 10 200 2500 40
BigIron RX(config-routemap DAMPENING_MAP)# exit
BigIron RX(config)# route-map DAMPENING_MAP permit 10
BigIron RX(config-routemap DAMPENING_MAP)# match address-filters 10
BigIron RX(config-routemap DAMPENING_MAP)# set dampening 20 200 2500 60
BigIron RX(config-routemap DAMPENING_MAP)# router bgp
BigIron RX(config-bgp)# dampening route-map DAMPENING_MAP