What should I do if the switch link aggregation fails?

This issue will share with you the basic principles of the Internet.

Possible causes

• The basic parameters on both ends do not match, for example, one end uses static aggregation and the other end uses LACP dynamic aggregation;
• Physical link problems, such as loose network cables and excessive fiber attenuation, lead to physical link abnormalities;
• If static aggregation fails to be configured on both ends of the device, the ports on both ends may not be directly connected, and there may be a relay node in between.
• If LACP dynamic aggregation devices are configured on both ends, the ports on both ends may not be directly connected, and there may be a relay node in the middle that does not forward LACP packets.
• Compatibility issues between the devices at both ends, such as the incompatibility of proprietary protocols with standard LACP.

Diagnostic Process

Steps

(1) Solve the physical link problem

Check whether the network cables or optical fiber connections corresponding to the ports participating in the aggregation are loose. If so, tighten them in time.

For optical fiber links, use an optical power meter to detect the fiber attenuation. If the attenuation is too large, replace the fiber with a qualified one.

(2) Unified aggregation mode at both ends

Log in to the management interface of the devices at both ends or use the command line to view the current aggregation mode configuration.

The aggregation modes at both ends are inconsistent. Adjust them to the same mode.

• If you choose static aggregation, ensure that both ends are configured as static aggregation;

• If you select LACP dynamic aggregation, ensure that the LACP protocol is enabled on both ends and configured in dynamic aggregation mode.

(3) Ensure static aggregation ports are directly connected

If static aggregation fails and there is an intermediate relay node, remove the intermediate relay node and directly connect the ports participating in static aggregation at both ends.

(4) Ensure LACP dynamic aggregation ports are directly connected

If LACP dynamic aggregation fails and the ports are not directly connected, adjust the ports at both ends to a direct connection state.

(5) Solve device compatibility issues

Check the protocol support status of the devices at both ends to confirm whether there is any incompatibility between the proprietary protocol and standard LACP.

If compatibility issues exist, try adjusting the aggregation protocol of one device to one that is compatible with the other. If the device supports it, upgrade the device firmware to enhance protocol compatibility or replace it with a compatible device for link aggregation.