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arna
arna
New Member
August 18, 2025
Question

FortiAP SN in Certificate differs to actual Serial Number of device

  • August 18, 2025
  • 2 replies
  • 654 views

We have an issue with a FortiAP U421E. It fails to connect to the fortigate because of a SN missmatch.

 

ap-sn-mismatch

JOIN REQ from WTP is denied due to SN mismatch

AP's SN in cert is PU421E3X16xxxxxx, while SN in JOIN-REQ is PU421E3X16yyyyyy.

 

Same behaviour on factory defaults with initial firmware.

 

Has anyone suggestions how to solve the problem?

2 replies

adambomb1219
SuperUser
adambomb1219
SuperUser
August 18, 2025

What firmware? Upgrade it to the latest and try again.

Also 421e is EOL since 2023.

    arna
    arnaAuthor
    New Member
    August 25, 2025

    Thank you. I am aware that the AP is EOL. Its for my homelab. Firmware makes no difference. Its the same issue from factory defaults to latest availabe on 7.0.5. Version.

    adambomb1219
    SuperUser
    adambomb1219
    SuperUser
    September 3, 2025

    What version is the FortiGate running? Also where did you purchase this AP?

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