Check the diagnostic information, which shows that the received optical power is low, with a threshold of -3 to -23. Once it exceeds the threshold, an alarm will be triggered. Troubleshoot the link, and if the link is normal, replace the optical. After you execute the display logbuffer command to view system logs, a log shows that the transceiver module is not H3C-compliant. H3C therefore shall NOT guarantee the normal function of the device or assume the maintenance. Collecting log and operating information IMPORTANT: To quickly locate faults, verify that the following features are enabled: • Information center—Enabled by default. To enable the log file feature. To restrict the use of third-party modules on their devices, host manufacturers usually conduct inspections on the optical modules that are connected, including but not limited to reading the optical module manufacturer name, model number, serial number, custom part of the data (encrypted. Optical modules are widely used in switches, network cards, routers, and other communication equipment. By default, a large number of alarm messages will be generated if the module is verified as non-H3C original. This guide uses the H3C S6820 switch as an.