Configuring BGP soft-reset
After you modify the route selection policy (for example, modify the preferred value), you must reset BGP sessions to apply the new policy. The reset operation tears down and re-establishes BGP sessions.
To avoid tearing down BGP sessions, you can use one of the following soft-reset methods to apply the new policy:
Enabling route-refresh—The BGP router advertises a route-refresh message to the specified peer, and the peer resends its routing information to the router. After receiving the routing information, the router filters the routing information by using the new policy.
This method requires that both the local router and the peer support route refresh.
Saving updates—Use the peer keep-all-routes command to save all route updates from the specified peer. After modifying the route selection policy, filter routing information by using the new policy.
This method does not require that the local router and the peer support route refresh but it uses more memory resources to save routes.
Manual soft-reset—Use the refresh bgp command to enable BGP to send local routing information or advertise a route-refresh message to the specified peer so the peer resends its routing information. After receiving the routing information, the router filters the routing information by using the new policy.
This method requires that both the local router and the peer support route refresh.
Enabling route-refresh
To enable BGP route refresh for a peer or peer group (IPv4):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| Use either method. By default, BGP route refresh is enabled. |
To enable BGP route refresh for a peer or peer group (IPv6):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| Use either method. By default, BGP route refresh is enabled. |
Saving updates
To save all route updates from the specified peer or peer group (IPv4):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP view or BGP-VPN instance view. |
| N/A |
3. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. | address-family ipv4 [ unicast ] | N/A |
4. Save all route updates from the peer or peer group. | peer { group-name | ip-address } keep-all-routes | By default, the routes are not saved. This command takes effect only for the routes received after this command is executed. |
To save all route updates from the specified peer or peer group (IPv6):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP view | bgp as-number | N/A |
3. Enter BGP IPv6 unicast address family view. | address-family ipv6 [ unicast ] | N/A |
4. Save all route updates from the peer or peer group. | peer { group-name | ipv6-address } keep-all-routes | By default, the routes are not saved. This command takes effect only for the routes received after this command is executed. |
Configuring manual soft-reset
To configure manual soft-reset (IPv4):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, BGP route refresh is enabled. |
4. Return to user view. | return | N/A |
5. Perform manual soft-reset. | refresh bgp { ip-address | all | external | group group-name | internal } { export | import } ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] | N/A |
To configure manual soft-reset (IPv6):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, BGP route refresh is enabled. |
4. Return to user view. | return | N/A |
5. Perform manual soft-reset. | refresh bgp { ipv6-address | all | external | group group-name | internal } { export | import } ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] | N/A |