Recently, I was scorched by many faults, especially Eth-Trunk faults. I have accumulated Eth-Trunk fault location experiences and share them with all of you.

An Eth-Trunk in manual load balancing mode cannot be Up. How do we locate this fault?

I summarize the following troubleshooting roadmap, which is of great help.

  Check whether the physical status of the Eth-Trunk member interface is Up.

  Check whether the lower threshold for the number of active interfaces of an Eth-Trunk is set.

The procedure is as follows:

Step 1: Check whether the physical status of Eth-Trunk member interfaces is Up.

The physical status of Eth-Trunk member interfaces must be Up so that the Eth-Trunk can work normally.

Run the display eth-trunk command to check Eth-Trunk member interfaces. If the status of Eth-Trunk member interfaces is Down, run the display interface command to check the physical status of Eth-Trunk member interfaces. If the physical status of member interfaces is Down, rectify interface faults.

Step 2: Check the Eth-Trunk configuration.

Run the display eth-trunk command to check whether the lower threshold for the number of active interfaces of an Eth-Trunk is set. The lower threshold for the number of active interfaces is used to ensure the minimum bandwidth. If the number of Eth-Trunk member interfaces in Up state is lower than the lower threshold, the Eth-Trunk status becomes Down. In the following figure, the lower threshold is 3, but there is only one Eth-Trunk member interface in Up state. The Eth-Trunk status is Down.

By default, the lower threshold for the number of active interfaces is 1. The lower threshold can be set using the least active-linknumber link-number command. By default, the upper threshold for the number of active interfaces is 8. The upper threshold for the number of active interfaces can be set using the max active-linknumber link-number command.

Step 3: If the fault persists after the preceding operations are performed, how to rectify the fault? Don't worry. You can collect information and contact Huawei technical support personnel.

When the Eth-Trunk works in LACP mode, negotiation fails. How do we locate this fault?

I also summarize the following troubleshooting roadmap:

  Check whether the physical status of the Eth-Trunk member interfaces is Up.

  Check whether the upper threshold for the number of active interfaces of the Eth-Trunk is set.

  Check whether Eth-Trunk member interfaces can receive and send LACPDUs.

The procedure is as follows:

Step 1: Check whether the physical status of Eth-Trunk member interfaces is Up.

The physical status of Eth-Trunk member interfaces must be Up so that the Eth-Trunk can work normally.

Run the display eth-trunk command to check Eth-Trunk member interfaces. If the status of Eth-Trunk member interfaces is Down, run the display interface command to check the physical status of Eth-Trunk member interfaces. If the physical status of member interfaces is Down, rectify interface faults.

Step 2: Check the Eth-Trunk configuration.

Check whether devices at both ends of the Eth-Trunk use consistent configuration. Both devices must be configured to work in LACP mode due to LACPDU negotiation. It is recommended that other configurations be consistent.

Run the display eth-trunk command to check whether the upper and lower thresholds for the number of active interfaces of an Eth-Trunk are set. If the number of Eth-Trunk member interfaces in Up state is lower than the lower threshold, the Eth-Trunk becomes Down.

By default, the lower threshold for the number of active interfaces is 1. The lower threshold can be set using the least active-linknumber link-number command. By default, the upper threshold for the number of active interfaces is 8. The upper threshold for the number of active interfaces can be set using the max active-linknumber link-number command.

If the least active-linknumber command has been configured before you run the max active-linknumber command, ensure that the upper threshold is higher than or equal to the lower threshold.

Step 3: Check whether Eth-Trunk member interfaces can receive and send LACPDUs.

Run the display lacp statistics eth-trunk command to check whether Eth-Trunk member interfaces can receive and send LACPDUs.

The number of increased packets is relevant to the timeout interval.

 [Quiday-Eth-Trunk1] lacp timeout slow/fast

After the timeout interval in fast mode is configured, the remote device sends LACPDUs at intervals of 1s. The performance is good, but more resources are occupied compared with the slow mode. After the timeout interval in slow mode is configured, the remote device sends LACPDUs at intervals of 30s. The response is slower compared with the fast mode, but fewer system resources are occupied. The timeout intervals at both ends can be different. To facilitate maintenance, you are advised to use the same timeout interval on both devices.

If the number of received LACPDUs increases incorrectly, check whether the remote device sends LACPDUs or the local device discards the received LACPDUs. If the statistics on LACPDUs received by the local device is incorrect, find the reason why the local interface does not receive LACPDUs correctly.

On the S2300, S3300SI, S3300EI, S5300EI, S5300SI, and S5710LI, if the local device does not receive LACPDUs sent by the remote device, check whether the bpdu enable command is used on the Eth-Trunk.

Step 4: If the fault persists after the preceding operations are performed, how to rectify the fault? Don't worry. You can collect information and contact Huawei technical support personnel.

The sharing is over. I hope the preceding solutions can help you easily rectify Eth-Trunk faults.

Tips

You can use the following methods to check the Eth-Trunk working mode.

Method 1: Run the display eth-trunk command to check the WorkingMode field.

Method 2: Check the Eth-Trunk configuration.