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FTP connection does not work on Plesk: FTP 550 SSL/TLS required on the control channel

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Taras Ermoshin
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Plesk Onyx for Linux kb: technical ABT: Group A

Applicable to:

  • Plesk Onyx for Linux
  • Plesk 12.5 for Linux
  • Plesk 12.0 for Linux
  • Plesk 11.x for Linux

Symptoms

Unable to connect to FTP server on Plesk:

# ftp domain.tld 21
550 SSL/TLS required on the control channel
Login failed.
Remote system type is UNIX.
Using binary mode to transfer files.

Cause

Allow only secure FTPS connections option is enabled.

Resolution

  1. Log into Plesk
  2. Set Allow both secure FTPS and non-secure FTP connections in
    Plesk > Tools & Settings > Security Policy
    Screenshot_2019-01-14_at_11.45.23.png

Comments

2 comments

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    Edwin C (Edited )

    After enabling both secure and non-secure FTP passive mode fails to work.

    Update: After lot of testing the issue was found to be due to the "MasqueradeAddress" parameter. This does not allow both ftps and passive mode ftp on a server using NAT. Also, changing the mode to only non-secure ftp in the panel does not remove this configuration and hence passive mode still fails.

    FYI, all plesk updates are installed and plesk onyx runs on Ubuntu 16.04 with systemd.

    Update2: Found that removing the MasqueradeAddress entries from proftpd configuration fixes the issue and allows both passive & active ftp to work simultaneously. Not sure why Plesk adds this to cause issues.

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    Julian Bonpland Mignaquy

    Edwin C Since the error you are receiving is quite general I recommend opening a support ticket with us for further troubleshooting: https://support.plesk.com/hc/en-us/articles/213608509-How-to-submit-a-request-to-Plesk-support-

     

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