Technical Tip: POE fault 4 - Port is yet undefined

Sometimes it is possible to face issues with the FortiSwitches-1xx series (108E POE/FPOE, 124E POE/FPOE, FSW148E-POE). POE does not work after a power fluctuation.

In such a scenario, log in to FortiSwitch CLI and check the below output:

get switch poe inline

If this error 'POE fault 4 - Port is yet undefined' is visible, then check the POE version on the FortiSwitch:

get hardware status

In this output, check the POE version. If it shows v1.8.8, then it is necessary to upgrade to v2.1.8:

Poe Firmware v1.8.8.

Steps to upgrade the POE version to v2.1.8:

1. Based on the FortiSwitch model, upgrade the FortiSwitches to v6.4 build5695. The direct download link is no longer available. Contact TAC to get firmware images.
2. Once the FortiSwitch upgrade is complete, check the FortiSwitch and POE version using the commands 'get system status' and 'get hardware status'. Make sure the POE version is upgraded to v2.1.8.0.
3. Upgrade the FortiSwitches to a GA version, preferably one of the latest FortiSwitch versions or in case of managed FortiSwitch, a compatible FortiSwitch version with FortiGate version: FortiLink Compatibility.

Contact the support hotline if necessary and attach the output of 'diag debug report' from FortiSwitch:

If the POE version was already v2.1.8, but facing the same POE issue.

Related articles:

Troubleshooting Tip: Diagnosing a PoE fault on a FortiSwitch