Figure 1 Schematic of Transceiver Connected to Switch 1. Port Link & Transceiver Working Status Run command: show interface <interface-type> <interface-number> It displays port negotiation speed, transceiver type, link status (UP indicates normal link) and traffic. 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 includes Doppler. The Catalyst 9400 series switch is a modular system. You can see which modules are installed, and the MAC address ranges and version numbers for each module, by entering the show module command. Use the mod_num argument to specify a particular module number and display detailed information on that. Connect to the Cisco switch using a console cable or through a remote management interface. Enter the privileged EXEC mode by typing "enable" and providing the enable password if prompted. We connect Moduletek SFP-25G-SR transceiver to Cisco. If you run fiber or copper uplinks in a small office, home lab, or data closet, SFPs (and SFP+) are the little parts that keep your links alive. This guide gives a practical, CLI-focused workflow for checking SFP health and diagnostics on Cisco switches, shows the exact commands you'll use. Digital Optical Monitoring (DOM) is a feature that allows for the real-time monitoring of various physical and operational parameters of fiber optic transceivers, such as transmit power, receive power, temperature, laser bias current, and voltage. DOM is supported on MS120, MS125, MS130, MS210.
