Execute the following command to view detailed interface and optical module status: show interface <interface-type> <interface-number>Execute the following command to view detailed interface and optical module status: show interface <interface-type> <interface-number>When optical modules operate on a switch, it is usually necessary to read the module's internal information to understand its working status—such as connection status and real-time metrics like optical power and temperature. Additionally, identifying module information helps detect coding. Optical module identification and status monitoring are essential daily tasks for network engineers maintaining Cisco switching systems. This guide provides complete, step-by-step CLI commands to view module type, DOM/DDM diagnostic data, vendor details, and compatibility information, fully. This guide gives a practical, CLI-focused workflow for checking SFP health and diagnostics on Cisco switches, shows the exact commands you'll use, explains what the numbers mean, and compares OEM (Cisco) vs third-party modules so you can pick the right SFP module supplier for reliability and cost. For this reason, network administrators frequently need to check SFP modules using switch diagnostics, command-line tools, and optical monitoring data. Many enterprise switches from vendors like Cisco and Juniper Networks provide built-in commands that allow engineers to read Digital Optical. By checking module health, compatibility, and digital diagnostics, you can quickly confirm correct installation, detect optical problems, and maintain accurate hardware inventory.