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. The peer then 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 unicast/multicast address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP instance view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled. |
To enable BGP route refresh for a peer or peer group (IPv6 unicast/multicast address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP instance view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled. |
Saving updates
To save all route updates from the specified peer or peer group (IPv4 unicast/multicast address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP IPv4 unicast address family view, BGP-VPN IPv4 unicast address family view, or BGP IPv4 multicast address family view. |
| N/A |
3. Save all route updates from the peer or peer group. | peer { group-name | ipv4-address [ mask-length ] } 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 unicast/multicast address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP IPv6 unicast address family view, BGP-VPN IPv6 unicast address family view, or BGP IPv6 multicast address family view. |
| N/A |
3. Save all route updates from the peer or peer group. | peer { group-name | ipv6-address [ prefix-length ] } 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 unicast/multicast address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP instance view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled. |
4. Return to user view. | return | N/A |
5. Perform manual soft-reset. | refresh bgp [ instance instance-name ] { ipv4-address [ mask-length ] | all | external | group group-name | internal } { export | import } ipv4 { multicast | [ unicast ] [ vpn-instance vpn-instance-name ] } | N/A |
To configure manual soft-reset (IPv6 unicast/multicast address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP instance view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled. |
4. Return to user view. | return | N/A |
5. Perform manual soft-reset. | refresh bgp [ instance instance-name ] { ipv6-address [ prefix-length ] | all | external | group group-name | internal } { export | import } ipv6 { multicast | [ unicast ] [ vpn-instance vpn-instance-name ] } | N/A |
To configure manual soft-reset (LS address family):
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter BGP instance view or BGP-VPN instance view. |
| N/A |
3. Enable BGP route refresh for a peer or peer group. |
| By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled. |
4. Return to user view. | return | N/A |
5. Perform manual soft-reset. | refresh bgp [ instance instance-name ] { ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] | all | external | group group-name | internal } { export | import } link-state | N/A |