(Optional) Configuring BGP Soft Reset

The inbound BGP soft reset allows the system to apply the new import policies immediately and refresh BGP routing table dynamically without tearing down any BGP connection.

Context

After changing a BGP import policy, you can reset BGP connections for the new import policy to take effect, interrupting these BGP connections temporarily. BGP route-refresh allows the system to refresh a BGP routing table dynamically without tearing down any BGP connection if routing policies are changed.

If a device's peer supports route-refresh, the refresh bgp command can be used on the device to softly reset the BGP connection with the peer and update the BGP routing table.
If a device's peer does not support route-refresh, the peer keep-all-routes command can be used on the device to remain all routing updates received from the peer so that the device can refresh its routing table without closing the connection with the peer.

Procedure

If the device's peers support route-refresh, perform the following operations:
1. (Optional) Enable route-refresh.
  1. Run system-view
    The system view is displayed.
  2. Run bgp as-number
    The BGP view is displayed.
  3. Run peer { ipv4-address | group-name } capability-advertise route-refresh
    Route-refresh is enabled.
  4. Run commit
    The configuration is committed.
  If route-refresh is enabled on all BGP peers and the import policy of the local router is changed, the local router sends a route-refresh message to peers or peer groups. After receiving the message, the peers or peer groups resend routing information to the local BGP device. This enables the local router to dynamically refresh its BGP routing table and apply the new routing policy without terminating any BGP connections.
2. Configure BGP soft reset.
  1. Run the refresh bgp [ vpn-instance vpn-instance-name ipv4-family | vpnv4 ] { all | ipv4-address | group group-name | external | internal } import command in the user view to trigger inbound BGP soft resetting.
  external softly resets an EBGP connection, and internal softly resets an IBGP connection.
If the device's peers do not support route-refresh, perform the following operations:
- Configure the device to store all the routing updates received from its peers or peer groups.
  1. Run system-view
    The system view is displayed.
  2. Run bgp as-number
    The BGP view is displayed.
  3. Run ipv4-family unicast
    The IPv4 unicast address family view is displayed.
  4. Run peer { ipv4-address | group-name } keep-all-routes
    The device is configured to store all the routing updates received from its peers or peer groups.
    
    After this command is used, all routing updates sent by a specified peer or peer group are stored, regardless of whether an import policy is used. When the local routing policy changes, the information can be used to regenerate BGP routes again.
    
    This command must be run on the local device and its peers. If the peer keep-all-routes command is run on the device for the first time, the sessions between the device and its peers are reestablished.
    
    The peer keep-all-routes command does not need to be run on the router that supports route-refresh. If the peer keep-all-routes command is run on the router, the sessions between the router and its peers will not be reestablished but the refresh bgp command does not take effect on the router.
  5. Run commit
    The configuration is committed.