timer revert delay (E-Trunk view)

Function

The timer revert delay command sets a switchback delay of an E-Trunk.

The undo timer revert delay command restores the default switchback delay of an E-Trunk.

The default switchback delay of an E-Trunk is 120 seconds.

Format

timer revert delay delay-value

undo timer revert delay

Parameters

Parameter	Description	Value
delay delay-value	Specifies a switchback t delay of an E-Trunk.	The value is an integer ranging from 0 to 10800, in seconds.

Parameter

Description

Value

delay delay-value

Specifies a switchback t delay of an E-Trunk.

The value is an integer ranging from 0 to 10800, in seconds.

Views

E-Trunk view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
etrunk	write

Usage Guidelines

Usage Scenario

If a member Eth-Trunk interface on the local master device of an E-Trunk goes Down physically, after Trunk negotiation, the peer member Eth-Trunk interface goes Up physically. Then, the peer device enters the master state, and the local device enters the backup state. When the fault on the local device is rectified, after Trunk negotiation, the local device returns to the master state.

When an E-Trunk works together with L2VPN services, after the fault on the master device is rectified, the status of the member Eth-Trunk interface on the master device is restored preferentially over PW. After the master device is recovered, if traffic on the member Eth-Trunk interface is immediately switched back to the master device, service traffic will be interrupted. In this situation, you need to set the switchback delay of the E-Trunk.

Configuration Impact

After the timer revert delay command is run to set the switchback delay of the E-Trunk, only when the switchback delay timer expires, the local member Eth-Trunk goes Up, and the local device of the E-Trunk returns to the master state. This delays switching traffic on the member Eth-Trunk back to the master device, and therefore prevents service traffic from being interrupted.

Precautions

The switchback delay of an E-Trunk must be greater than the PW recovery time. This ensures that services are not interrupted when traffic is switched back to the master device.

The configured E-Trunk switchback delay must be the same on the upstream and downstream devices; otherwise, service traffic may be lost.

When a CE is dual-homed to two PEs through an E-Trunk, if the maximum number of active links on the CE is 1, delayed switchback cannot be implemented for the E-Trunk. In this situation, you need to run the lacp preempt enable command on the CE to enable LACP preemption on the current Eth-Trunk interface and run the lacp preempt delay command to set the LACP preemption delay to be longer than the E-Trunk switchback delay.

Example

# Set the switchback delay of an E-Trunk to 100 seconds.

<HUAWEI> system-view
[~HUAWEI] e-trunk 1
[*HUAWEI-e-trunk-1] timer revert delay 100