Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 636)

If the system scans all route-map instances but finds no matches, or if a deny condition is
encountered, then it does not update the routes. Whenever a matched instance contains a deny
statement, the current traversal terminates, and none of the updates specified in the set statements of
the matched instances in both current and previous traversals are applied to the routes.
This supports a more programmable route-map configuration and route filtering scheme for BGP4
peering. It can also execute additional instances in a route map after an instance is executed by
means of successful match statements. You can configure and organize more-modular policy
definitions to reduce the number of instances that are repeated within the same route map.
This feature currently applies to BGP4 routes only. For protocols other than BGP4, continue
statements are ignored.
Configuring BGP
This section expands upon the preceding overview and provides the following additional BGP
management examples.
Adjusting defaults to improve routing performance
The following examples illustrate a variety of options for enabling and fine-tuning route flap
dampening.
To enable default dampening as an address-family function:
switch(config)# rbridge-id 10
switch(config-rbridge-id-10)# router bgp
switch(config-bgp-router)# address-family ipv4 unicast
switch(config-bgp-ipv4u)# dampening
To change the all dampening values as an address-family function:
switch(config)# rbridge-id 10
switch(config-rbridge-id-10)# router bgp
switch(config-bgp-router)# address-family ipv4 unicast
switch(config-bgp-ipv4u)# dampening 20 200 2500 40
NOTE
To change any of the parameters, you must specify all the parameters in the command in the following
order: half-life, reuse, suppress, max-suppress-time. To leave any parameters unchanged, enter
their default values.
For more details about the use of route maps, including more flap-dampening options, refer to Using
route maps with match and set statements on page 636.
Using route maps with match and set statements
This section presents the following match and set examples.
Matching on an AS-path ACL
To configure a route map that matches on AS-path ACL 1:
switch(config)# rbridge-id 5
switch(config-rbridge-id-5)# route-map myaclroutemap1 permit 10
switch(config-route-map-myaclroutemap1/permit/10)# match as-path 1
Configuring BGP
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