| Description |
This article describes an issue where the FortiGate-400F and 600F exhibit loud fan noise after upgrading to v7.2.6, v7.2.7, and v7.4.0, without high CPU/memory usage. The cause is identified as FortiOS known issue 952194: temperature sensors not being read correctly if all port blocks (port1-port8, port9-port16) are administratively down AND the FortiGate has been rebooted. Consequently, the fan controller increases the speed significantly, mistakenly believing the FortiGate is overheating. |
| Scope | FortiGate-400F/600F v7.2.6, v7.2.7, v7.4.0, and v7.4.2. |
| Solution |
In models 400F or 600F, temperature sensor information is available under Dashboard -> Status -> Sensor Information.
To check from the CLI, run the command: 'execute sensor list'. This will display sensors 'TB PHYX7Y2' 'TB PHYX4Y2' or 'MV_88E1680_1', and 'MV_88E1680_0' detecting high temperatures when encountering this known issue.
... 43 MV_88E1680_0 .................. 127.0 C (over high) 44 MV_88E1680_1 .................. 127.0 C (over high) ... 32 TB NP7X14Y5 ................... 32.0 C 33 TB PHYX4Y2 .................... 32.0 C 34 TB PHYX7Y2 .................... 127.0 C (over high) ...
Sensors MV_88E1680_1/TB PHYX7Y2 and MV_88E1680_0/TB PHYX4Y2 are associated with port blocks port1-8 and port9-16, respectively. Check the output of 'show system interface' and 'show system virtual-switch' to see if ports port18 and port916 are set to administratively down ('set status down').
Workaround: Set at least one port from each port block (port1-port8, port9-port16) to 'up' status and then reboot the FortiGate.
If a virtual switch is configured for these two port blocks, remove one port from the virtual switch, set its status to 'up', and reboot. According to the developers, the issue is fixed in v7.4.2 and the upcoming v7.2.8. |
