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VaudeSport
VaudeSport
New Member
October 10, 2025
Question

Illegal port number in EPSV reply

  • October 10, 2025
  • 1 reply
  • 1826 views

We use a FortiGate 601E with v6.4.9.
Since the last firmware upgrade, FTP transfers with EPSV have been failing. Locally, the FTP server responds with "|||PORT|." However, the FortiGate translates this to "|||PORT" (the final "|" is missing).
Transfers with PASV continue to work.
I can't disable the session helper because it's required for PASV.

1 reply

AlexC-FTNT
Staff
AlexC-FTNT
Staff
October 13, 2025

The first step before everything is to bring that firmware into the real world (at least 7.2.12, and  recommended 7.4.8) and start troubleshooting from there. The issue may have been fixed already.

    InformaticaHN
    InformaticaHN
    New Member
    October 14, 2025

    Have this exact issue on our 80F after upgraded from v7.2.11 to v7.2.12 and on our 40F after the same upgrade. Tried to upgrade the 40F to v7.4.9 with no success. Back to v7.2.11 on 40F to be able to work normally.

    AlexC-FTNT
    Staff
    AlexC-FTNT
    Staff
    October 14, 2025

    I doubt the "exact issue" is the best wording here. I am running multiple FTP servers over FG with 7.2.12 without facing this problem. Filezilla in my case uses PASV command on every server connection. EPSV is used in IPV6 only. Check your inspection profiles in policy(test by removing them all, or using deep/inspection+proxy-mode policy), and make sure the FTP session-helper was not deleted by mistake.

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