Brocade BigIron RX Series Configuration Guide - Manual (Page 929)

BigIron RX Series Configuration Guide 851
53-1002484-04
Configuring BGP4 neighbors
27
Removing route dampening from suppressed
neighbor routes
You can selectively unsuppress more-specific routes that have been suppressed due to
aggregation, and allow the routes to be advertised to a specific neighbor or peer group.
Here is an example.
In the example above, the aggregate-address command configures an aggregate address of
209.1.0.0 255.255.0.0. and the summary-only parameter prevents the device from advertising
more specific routes contained within the aggregate route.
Entering a show ip bgp route command for the aggregate address 209.1.0.0/16 shows that the
more specific routes aggregated into 209.1.0.0/16 have been suppressed. In this case, the route
to 209.1.44.0/24 has been suppressed. If you enter the command below, the display shows that
the route is not being advertised to the device’s BGP4 neighbors.
If you want to override the summary-only parameter and allow a specific route to be advertised to a
neighbor, enter commands such as the following.
The ip prefix-list command configures an IP prefix list for network 209.1.44.0/24, which is the
route you want to unsuppress. The next two commands configure a route map that uses the prefix
list as input. The neighbor command enables the device to advertise the routes specified in the
route map to neighbor 10.1.0.2. The clear command performs a soft reset of the session with the
neighbor so that the device can advertise the unsuppressed route.
Syntax: [no] neighbor <ip-addr> | <peer-group-name> unsuppress-map <map-name>
BigIron RX(config-bgp)# aggregate-address 209.1.0.0 255.255.0.0 summary-only
BigIron RX(config-bgp)# show ip bgp route 209.1.0.0/16 longer
Number of BGP Routes matching display condition : 2
Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST C:CONFED_EBGP D:DAMPED
E:EBGP H:HISTORY I:IBGP L:LOCAL M:MULTIPATH S:SUPPRESSED F:FILTERED
Prefix Next Hop Metric LocPrf Weight Status
1 209.1.0.0/16 0.0.0.0 101 32768 BAL
AS_PATH:
2 209.1.44.0/24 10.2.0.1 1 101 32768 BLS
AS_PATH:
BigIron RX(config-bgp)# show ip bgp route 209.1.44.0/24
Number of BGP Routes matching display condition : 1
Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST C:CONFED_EBGP D:DAMPED
E:EBGP H:HISTORY I:IBGP L:LOCAL M:MULTIPATH S:SUPPRESSED F:FILTERED
Prefix Next Hop Metric LocPrf Weight Status
1 209.1.44.0/24 10.2.0.1 1 101 32768 BLS
AS_PATH:
Route is not advertised to any peers
BigIron RX(config)# ip prefix-list Unsuppress1 permit 209.1.44.0/24
BigIron RX(config)# route-map RouteMap1 permit 1
BigIron RX(config-routemap RouteMap1)# match prefix-list Unsuppress1
BigIron RX(config-routemap RouteMap1)# exit
BigIron RX(config)# router bgp
BigIron RX(config-bgp)# neighbor 10.1.0.2 unsuppress-map RouteMap1
BigIron RX(config-bgp)# clear ip bgp neighbor 10.1.0.2 soft-out