top of page
  • Writer's pictureMatt Sherif

FAP U431F doesn't come up after registration

My colleague and good friend Manny Fernandez posted this article about FAP-U431F APs not registering. As a follow up I wanted to post a situation I ran into with the FAP-U431F when it properly registers, and doesn't come back up after authorization.

I had a customer reach out to me that they connected the FAP-U431F they just purchased and authorized via their FortiGate did not come up after that. Upon looking into this I found a release notes article stating that some of the U431F's shipped with trial firmware (build 0000) that is incompatible with any GA version of FortiOS.


  • FortiGate running FortiOS 6.2.2

  • FortiAP U431F being used - and already authorized


To get the FAP-U431F to come online with the trial firmware you will need to apply the following workaround:

  • One thing to note is that FortiAP U43xF profiles are not yet supported via the WebUI in 6.2.2, for further known issues check out the release notes

  • Log into the FortiGate CLI and disable radio-3 in the FAP-U431F default profile:

  • Go to the Fortinet Support website and download the latest supported FortiAP-U firmware file (FortiAP-U 6.0.1 as of the writing of this article)

  • Go WiFi & Switch Controller > Managed FortiAPs and select the FAP-U431F/FAP-U433F in question

  • Right click and select upgrade

  • Once the firmware is upgraded you can re-enable radio-3 from the CLI

And that's it! Thank you for taking the time to read this, I hope it was helpful.

751 views0 comments

Recent Posts

See All


bottom of page