This problem can be detected by checking whether the light port is on, then checking whether the light module parameters such as wavelength, speed and transmission distance match, and then checking whether the gateway is configured and whether the VLAN is the same. This document describes how to check the switch interface or port status and how to locate an interface physically down fault and restore the interface to the up state. Hardware failures: include hardware. Problem: All optical ports cannot be connected, and the indicator lights are not on. We want to troubleshoot transceiver on Huawei router, Huawei switch, Huawei systems. from transceivers Check “Alarm information” section for warnings, LOS Alarm means no inbound signal, execute display this to check shutdown mode, execute undo shutdown if necessary.