Run the following command to view interface configuration and status: show port <port_number> configuration Add no-refresh to disable automatic screen refresh: show port <port_number> configuration no-refresh The output includes: • Interface speed and duplex mode • Optical. Run the following command to view interface configuration and status: show port <port_number> configuration Add no-refresh to disable automatic screen refresh: show port <port_number> configuration no-refresh The output includes: • Interface speed and duplex mode • Optical. Monitoring the optical power of SFP (Small Form-factor Pluggable) modules is a critical step in maintaining stable network links. Even if an interface appears up, degraded Tx/Rx levels can cause intermittent flapping, packet loss, or err-disabled states. Checking optical power helps pinpoint issues. This document describes how to troubleshoot fiber optic interfaces by addressing some of the fiber optic module and cabling specifications. There are no specific requirements for this document. This guide gives a practical, CLI-focused workflow for checking SFP health and diagnostics on Cisco switches, shows the exact commands you'll use. By reading internal parameters of optical transceivers on switches, users can monitor link status, real-time transmit/receive power, operating temperature and other data. We connect Moduletek SFP-25G-SR transceiver to Cisco. The Cisco Small Business Series Switches allow you to plug in a Small Form-factor Pluggable (SFP) transceiver in their optical modules to connect fiber optic cables. Once the transceiver and fiber optic cable are plugged in properly in the switch optical module, you should be able to view the. However, the command for Cisco SMB switches differs from the above. The command is like this: To access the Cisco switch's privileged EXEC mode, use the 'fiber-ports-optical-transceiver' CLI.