OneLinersCommand workbench
Verified diagnostic signature

The FTP control or data connection was rejected by authentication, authorization, or network mode.

Match output from ftp, understand the likely cause, then continue with sourced, read-only checks.

Confidence
high
Platforms
linux · macos · windows
Verified
2026-07-24
Recognized output

Signature matched locally

550 Permission denied

OneLiners matches this pattern in your browser. Your pasted output is not stored or indexed.

Likely causes

What usually produces this signal

  1. Wrong credentials
  2. Account or path policy
  3. Passive data port blocked
  4. Server-side filesystem access
Safe next checks

Collect evidence before changing the system

01

Connect to a TCP service and read its banner with netcat

printf '\n' | nc -v -w 5 <host> <port>

The output matches the expected target and exits without an error.

02

List files in a remote FTP directory with curl

curl --fail --show-error --list-only --user <username> ftp://<host>/<remote-path>/

The output matches the expected target and exits without an error.