Starting a BGP Process

Procedure

1. Run system-view

   The system view is displayed.

2. (Optional) Run route loop-detect bgp enable

   BGP routing loop detection is enabled.

   After this function is enabled, the device reports an alarm when detecting a BGP routing loop. Because the device cannot determine whether a routing loop is removed, the alarm will not be cleared automatically even if the routing loop is removed. To manually clear the BGP routing loop alarm, run the clear route loop-detect bgp alarm command.

3. Run bgp { as-number-plain | as-number-dot }

   BGP is started (with the local AS number specified), and the BGP view is displayed.

4. (Optional) Run router-id ipv4-address

   A BGP router ID is configured.

   Configuring a new BGP router ID or changing the existing one will reset the BGP peer relationship between routers.

   

   By default, BGP automatically selects a router ID in the system view as its router ID. If the IP address of a physical interface is used as the BGP router ID, route flapping occurs when this IP address changes. To enhance network stability, configure the IP address of a loopback interface as the router ID. For rules in selecting router IDs from the system view, see the router-id command description in the "Command Reference."

   By default, Cluster_List takes precedence over router ID during BGP route selection. To enable router ID to take precedence over Cluster_List during BGP route selection, run the bestroute routerid-prior-clusterlist command.

5. (Optional) Run shutdown

   All sessions between the device and its BGP peers are terminated.

   Frequent BGP route flapping may occur during system upgrade and maintenance. To prevent this from impacting the network, perform this step.

   

   After an upgrade or maintenance, run the undo shutdown command to restore the BGP sessions; if you do not run this command, BGP functions will not work properly.

6. Run commit

   The configuration is committed.