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Araujoctr
Araujoctr
Explorer III
November 6, 2025
Question

Fortigate FortiWifi 40F - v7.4.9

  • November 6, 2025
  • 1 reply
  • 952 views

 

Dear Sir/Madam,

I am experiencing a situation where my Fortigate (FortiWifi 40F) is experiencing unexpected power outages (the Fortigate suffered an unexpected power failure!) and even with VPN tunnels up, the equipment only works again after a reboot. Has anyone here encountered a similar situation? Thank you for your attention.

 

 

Device shutdown.bmp

 

1 reply

ede_pfau
SuperUser
ede_pfau
SuperUser
November 6, 2025

Hello,

and welcom to the forums.

 

The reason for the power is external, right? Even if the FGT in your perception is failing without reason (that is, without a noticeable power failure), it still might have been a glitch on mains which causes the power supply to fail.

Two things come to my mind:

1- consider getting a UPS  (uninterruptible power supply) for your FGT, switch and modem. Cost is moderate, protection is guaranteed and cost saving in case of overvoltage is high.

2- (at least) let the FGT repair it's filesystem automatically on reboot. Combined with a daily reboot, you would not have to worry about device health so much. Of course, if the device fails in the middle of the day, nothing else but a reboot will help.

 

conf sys global

   set auto-fsck enable

   set daily-restart enable

   set restart-time HH:MM

end

 

It could be a faulty power supply as well. IIRC, the 40F has an external plug-in PSU, but nothing too exotic (5V? 9V?). You might try another one.

Chances that you have a lemon here are small though.

Araujoctr
AraujoctrAuthor
Explorer III
November 7, 2025

Dear Sir/Madam, thank you for your attention to this situation.

It is striking that we have several firewalls of this model (FortiWifi 40F) in our network, and a group of these devices are exhibiting this behavior. They are distributed across different cities, yet this network unavailability occurs on these units, even with VPN tunnels up.

ede_pfau
SuperUser
ede_pfau
SuperUser
November 7, 2025

Hello,

I just want to add that to my knowledge there is no known weakness in the hardware of this particular model. Still, my suspicion would be that the plug-in power supply might be at fault - less tolerant to over- or undervoltage. 

If you could reproduce the situation in your lab (on your desktop), you could observe whether other IT equipment is failing at the same moment. If not, get a different (brand of) power supply to eliminate or confirm this as the source of failure. I know, the snap-in plug is "special", but you can buy these online.

 

Lot of hassle, I feel you. If it gets too insecure, you can always open a support case and ask for a hardware replacement. Fortinet will try to pin down the source of failure in it's own interest, so either FGT or power supply.

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