Dell PowerConnect B-RX BigIron RX Series Configuration Guide v02.8.00 - Page 927

Displaying BGP4 information 26 match address-filters 11 set community 11:12 no-export route-map permit1122 permit 12 match ip address 11 route-map permit1122 permit 13 match ip address std_22 This example shows that the running configuration contains six route maps. Notice that the match and set statements within each route map are listed beneath the command for the route map itself. In this simplified example, each route map contains only one match or set statement. To display the active configuration for a specific route map, enter a command such as the following, which specifies a route map name. BigIron RX# show route-map setcomm route-map setcomm permit 1 set community 1234:2345 no-export This example shows the active configuration for a route map called "setcomm". Syntax: show route-map [] Graceful restart in BGP Under normal operation, restarting a BGP router causes the network to be reconfigured. In this situation, routes available through the restarting router are first deleted when the router goes down and are then rediscovered and re-added to the routing tables when the router is back up and running. In a network where routers are restarted regularly, this can degrade performance significantly and limit the availability of network resources. BGP graceful restart dampens the network topology changes and limits route flapping by allowing routes to remain available between routers during a restart. BGP Graceful restart operates between a router and its peers and must be configured on both the router and its peers. A BGP router with graceful restart enabled advertises its graceful restart capability and restart timer to establish peering relationships with other routers. Once the restarting router is restarted, it begins to reestablish BGP connections and receive routing updates from its peers. When the restarting router receives all end-of-RIB markers from its helper neighbors, all of the routes are recomputed, and newly computed routes replace the stale routes in the routing table. An end-of-RIB marker indicates that it has received all of the BGP route updates. During the restarting process, the helper neighbors will continue to use all of the routes learned from the restarting router and mark them as stale for the length of the learned restart timer. If the restarting router doesn't come back up within the restart timer, the routes marked stale will be removed. Configuring BGP graceful restart To configure BGP Graceful Restart, you must enable it on all BGP peers where you want it to operate and set the following timers: • Restart Timer • Stale Routes Timer BigIron RX Series Configuration Guide 851 53-1002253-01