FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
dtogkas
Staff
Staff
Article Id 397945
Description This article describes scenarios when a False Positive Power Supply Failure alert is generated on the NMS of the user using SNMP Polling for FortiGate models such as FortiGate_10xE/FortiGate_20xE.
Scope FortiOS v7.2.9+, v7.4.3+, v7.6.0+.
Solution

There are a few FortiGate models, such as the FortiGate_10xE/FortiGate_20xE, which do not include a Redundant Power Supply (RPS).

 

After installing FortiOS v7.2.9 or v7.4.3 or above in the FortiGate models FortiGate_10xE/FortiGate_20xE, the following System Event log will be generated:

 

date="2025-06-24" time="13:44:34" devid="xxxx" vd="root" type="event" subtype="system" action="ipmc-sensor-monitor" bid=58969441 devname="FG200E-1" dstepid=3 dsteuid=3 dvid=1497 epid=3 euid=3 eventtime=1750765474000 id=7516994200315923187 level="information" logdesc="Optional power supply not detected" logid="0100022106" logver=700120523 msg="Power Supply is not detected: PSU RPS LOST" status="anomaly" tz="+0200"

 

Running the command 'execute sensor list' on these FortiGates, it prompts the following output:


FG200E# execute sensor list
[HW monitor sensors]
1 FAN 1 CPU Fan Speed .......... 4299 RPM
2 FAN 2 CPU Fan Speed .......... 4687 RPM
3 FAN 3 REAR FAN ............... 4470 RPM
4 TMP 1 Thermal sensor 1 ....... 29.0 C
5 TMP 2 Thermal sensor 2 ....... 31.0 C
6 TMP 3 Thermal sensor 3 ....... 31.0 C
7 PSU MAIN ...................... OK
8 PSU RPS ....................... LOST

 

The output shows that the PSU RPS is lost from the device, but, in reality, there is no PSU RPS available for this model.

 

Debugging the IPMC Monitor will show the following information:


FG200E# diagnose debug application ipmc -1
Debug messages will be on for 30 minutes.
FG200E# diagnose debug enable

FG200E# hw_monitor_read_sensor_value()-691: 'PSU MAIN' sensor value is {+1.00}
hw_monitor_read_sensor_value()-691: 'PSU RPS' sensor value is {+0.00}

 

The value of the 'PSU_RPS' is zero.

 

When using a Network Monitoring System (NMS) to poll information from the FortiGate, a critical alert will be generated as a consequence of that.

This alert is a false positive, and there is no reason to be concerned when using FortiGate 10xE/20xE.

 

To bypass that issue, it would be needed to:

  1. Manually clear the log from the NMS System.
  2. Roll back to a working FortiOS version.

 

Contact TAC support if more information is needed.