Unidirectional Link Processing

When a unidirectional link is detected, DLDP shuts down the corresponding interface in either of the following ways:

• Manual mode: DLDP detects the unidirectional link, and the network administrator shuts down the interface manually. Upon detecting a unidirectional link, the local device only records logs and traps and prompts the network administrator to shut down the interface.

• Automatic mode: DLDP detects the unidirectional link, records logs and traps, and sets the interface state to DLDP Down. A DLDP Down interface receives and forwards only BPDUs, not user traffic.

The automatic mode is recommended on networks with high performance. When the network performance is poor, there may be a delay in receiving DLDPDUs, causing DLDP to mistakenly identify a unidirectional link. In this scenario, the manual mode is recommended. The network administrator manually shuts down the interface, preventing packet forwarding from being affected.