mpls l2vpn pw bit-error-detection

Function

The mpls l2vpn pw bit-error-detection command enables bit-error-triggered protection switching for an LDP PW.

The undo mpls l2vpn pw bit-error-detection command disables bit-error-triggered protection switching for an LDP PW.

By default, bit-error-triggered protection switching is disabled for an LDP PW.

Format

mpls l2vpn pw bit-error-detection

undo mpls l2vpn pw bit-error-detection

Parameters

None

Views

100ge sub-interface view, 100GE interface view, 10GE sub-interface view, 10GE interface view, 200GE sub-interface view, 25GE sub-interface view, 25GE interface view, 400GE Layer 2 sub-interface view, 400GE sub-interface view, 400GE interface view, 40GE sub-interface view, 40GE interface view, 50GE Layer 2 sub-interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk Layer 2 sub-interface view, Eth-Trunk sub-interface view, Eth-Trunk interface view, GE Layer 2 sub-interface view, GE optical interface view, GE sub-interface view, GE interface view, GE electrical interface view, Global VE sub-interface view, VE sub-interface view, XGE sub-interface view, XGE interface view, Layer 2 sub-interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2vpn	write

Usage Guidelines

Usage Scenario

BFD for PW and BFD for LSP, two commonly deployed detection mechanisms in PW redundancy scenarios, can trigger the active/standby switchover of PWs only after detecting the loss of three consecutive BFD packets.

To resolve this problem, run the mpls l2vpn pw bit-error-detection command on both endpoints of an LDP PW to enable bit-error-triggered PW switching. Bit-error-triggered PW switching uses CRC to check the bit error rate and works with the TE hot standby LSP or PW to protect services transmitted over a PW, ensuring end-to-end service quality of a PW.

Prerequisites

The mpls l2vpn command has been run to enable MPLS L2VPN.

Configuration Impact

After bit-error-triggered PW switching is enabled using the mpls l2vpn pw bit-error-detection command, the primary and secondary PWs respond to bit errors and perform an active/standby switchover as needed. In a scenario in which both the primary and secondary PWs are normal:

If the primary PW does not encounter a bit error event, the primary PW forwards traffic.
If the primary PW encounters a bit error event but the secondary PW does not, the secondary PW takes over traffic from the primary PW.
If the primary and secondary PWs both encounter a bit error event, the primary PW forwards traffic.

Example

# Enable bit-error-triggered protection switching for an LDP PW.

<HUAWEI> system-view
[*HUAWEI] mpls
[*HUAWEI-mpls] quit
[*HUAWEI] mpls l2vpn
[*HUAWEI-l2vpn] quit
[~HUAWEI] interface GigabitEthernet 0/1/0
[*HUAWEI-GigabitEthernet0/1/0] mpls l2vc 1.1.1.1 1
[*HUAWEI-GigabitEthernet0/1/0] mpls l2vc 2.2.2.2 2 secondary
[*HUAWEI-GigabitEthernet0/1/0] mpls l2vpn pw bit-error-detection