ESXi check the emitting power of the optical module

ESXi does not natively provide SFP/optical module power readings; you must use switch interfaces or server management tools like iDRAC or iLO to access this information.ESXi LimitationsESXi hosts allow you to query basic network adapter information using commands like:CodeCopyesxcli network nic get -n vmnicX This provides link status, port speed, and driver/firmware details, but does not include SFP transmit or receive power . Tools like ethtool are limited on ESXi and cannot retrieve optical module metrics such as the -m option available on Linux . Therefore, ESXi alone cannot directly measure the emitting power of an optical module.Alternative MethodsSwitch Monitoring Most managed switches provide SFP diagnostics, including TX/RX power, temperature, and voltage. You can log into the switch CLI or web interface to check the optical module connected to the ESXi host port .Server Management Interfaces If your ESXi host is on a server with iDRAC (Dell) or iLO (HP), these interfaces can sometimes report NIC and SFP status, including optical power readings. This requires access to the management console and may vary by NIC model .Monitoring Tools Tools like Checkmk or other VMware monitoring solutions can collect hardware sensor data via the vSphere API, but they rely on the host or switch exposing the SFP metrics. Direct optical power readings are usually only available if the switch or NIC supports reporting through the API .Recommended ApproachCheck the switch port connected to the ESXi host for optical power readings.Use iDRAC/iLO if available for additional NIC diagnostics.Combine ESXi NIC info with switch or management data to troubleshoot connectivity or signal issues. By combining these sources, you can effectively monitor the emitting power and health of optical modules even though ESXi itself does not provide direct access.