FTP Passive Port Range Checker
Verify that your FTP server’s passive mode port range is open and reachable through firewalls. Essential for diagnosing “unable to open data connection” errors.
What is passive mode?
In FTP passive mode (PASV), the server opens a random high-numbered port for data transfers and tells the client which port to connect to. If these ports are blocked by a firewall, file transfers will fail even though the control connection on port 21 works fine.
Common passive port ranges
| Range | Used by |
|---|---|
| 49152–65535 | IANA dynamic/ephemeral range (default on many servers) |
| 40000–40100 | Common custom range (cPanel, Plesk) |
| 30000–31000 | Common custom range (FileZilla Server default) |