The mpls l2vpn reroute command configures the revertive switchover policy for the primary and secondary PWs in FRR or PW redundancy master/slave mode.
The undo mpls l2vpn reroute command restores the default revertive switchover policy.
By default, delayed revertive switchover is configured in FRR or PW redundancy master/slave mode.
mpls l2vpn reroute { { delay delay-time | immediately } [ resume resume-time ] | never }
undo mpls l2vpn reroute
| Parameter | Description | Value |
|---|---|---|
delay delay-time |
Specifies the revertive switchover policy for the primary and secondary PWs as delayed revertive switchover, and sets the duration for delayed switchover. |
The value is an integer that ranges from 10 to 1800, in seconds. The default value is 30. |
immediately |
Specifies the revertive switchover policy for the primary and secondary PWs as immediate revertive switchover. |
- |
resume resume-time |
Specifies a delay after which the local device notifies the peer PE on the secondary PW of the recovery. You can set this parameter only in VLL FRR mode. |
The value is an integer that ranges from 0 to 600, in seconds. The default value is 10. |
never |
Specifies the revertive switchover policy for the primary and secondary PWs to none revertive switchover. After the primary PW recovers, traffic is not switched to it until the secondary PW is faulty. |
- |
Usage Scenario
The mpls l2vpn reroute command configures the revertive switchover policy for the primary and secondary PWs in FRR or PW redundancy master/slave mode.
Prerequisites
The primary and secondary PWs have been configured in FRR or PW redundancy master/slave mode. The revertive switchover policy cannot be configured for PW redundancy independent mode.
Precautions
In VLL FRR mode and in PW redundancy master/slave mode, the PW revertive switchover policy is classified into the following modes:
Immediate revertive switchover: When the primary PW recovers from a fault, the local PE switches traffic back to the primary PW immediately and notifies the peer PE on the secondary PW of the fault. In FRR mode, the local PE notifies the peer PE on the secondary PW of the recovery after a delay of resume-time. In PW redundancy master/slave mode, the parameter resume-time is not supported.
This revertive switchover applies to scenarios in which users hope traffic to be restored as soon as possible.
Delayed revertive switchover: When the primary PW recovers from a fault, traffic is switched back to the primary PW after a period specified by delay-time. After traffic is switched back, the local device immediately notifies the peer device on the secondary PW of the fault. If resume-time is configured in FRR mode, the local device notifies the peer device on the secondary PW of the recovery after a delay of resume-time.
On a large-scale network, packet loss caused by incomplete route convergence may occur during the switchback. To prevent this problem, configure traffic to be switched back after a delay.
None revertive switchover: When the primary PW recovers from a fault, traffic is not switched back to the primary PW until the secondary PW becomes faulty.
If you do not want traffic to be frequently switched between the primary and secondary PWs, you can use the non-revertive switchover.
In a CE asymmetrical networking, if the Ethernet OAM function is configured on a PE interface connected to a CE, and a revertive switchover policy is configured, the value of resume-time cannot be 0 seconds. The value must be equal to or greater than 1 second.
# Configure the device to switch traffic back to the primary PW 15 seconds after the primary PW recovers from a fault, notify the peer PE on the secondary PW of the fault when a switchover is performed, and notify the peer PE of the secondary PW of the recovery 20 seconds later.
<HUAWEI> system-view [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] mpls l2vc 10.1.1.9 100 [HUAWEI-Vlanif100] mpls l2vc 10.2.2.9 200 secondary [HUAWEI-Vlanif100] mpls l2vpn reroute delay 15 resume 20