FTPMonitor / Guides / FTP server requires FTPS

FTP server requires FTPS

Why plain FTP connections fail when a server requires FTPS encryption.

Diagnose this automatically

Verify whether authentication is the actual failure point.

terminal

npx ftpmonitor check --protocol ftps --host ftps.example.com --port 21 --username user --password pass

Shareable output

terminal

npx ftpmonitor check --protocol ftps --host ftps.example.com --port 21 --username user --password pass --format slack --copy

Some servers reject unencrypted FTP connections and require FTPS.

Common causes

FTP TLS handshake failed — Why FTPS TLS handshakes fail and how to troubleshoot certificate and encryption problems.
FTPS certificate error — Why FTPS certificate validation fails and how to fix expired or mismatched certificates.
FTP SSL negotiation failed — Why FTPS SSL negotiation fails and how to fix TLS configuration issues.
FTPS explicit vs implicit configuration — Understanding explicit vs implicit FTPS and why incorrect configuration causes connection failures.
Authentication failed — Why FTP/SFTP authentication fails and how to correct credential, key, and account policy issues.
FTP 530 Login incorrect — How to fix FTP 530 errors: bad credentials, account restrictions, FTPS requirements, and permission issues.