Port 989: FTPS-DATA
Port 989 is the data channel for FTPS, FTP secured with implicit TLS. It pairs with the control channel on port 990 to transfer files with encryption applied from the moment the connection opens.
| Port number | 989 |
|---|---|
| Service | FTPS Protocol (data) |
| Protocol | TCP |
| Category | File transfer |
| Default encryption | Yes (TLS/SSH) |
How do I check whether port 989 is open?
Port 989 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.
| Question | Command | What to know |
|---|---|---|
| Is it open on a remote host? | nc -vz example.com 989 | A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line. |
| Same check on Windows | Test-NetConnection example.com -Port 989 | Built into PowerShell. TcpTestSucceeded in the output is the answer; telnet is not installed by default on modern Windows. |
| What is listening locally? | ss -tlnp | grep ':989 ' | Lists the process bound to port 989 on Linux. On macOS use lsof -nP -iTCP:989 -sTCP:LISTEN, on Windows netstat -ano | findstr :989 |
Replace example.com with the host you are testing. A blocked port and a port with nothing listening on it look identical from the outside, so if a service should be running, check locally before blaming the firewall.
Frequently asked questions
What is port 989 used for?
Port 989 is the data channel for FTPS, FTP secured with implicit TLS. It pairs with the control channel on port 990 to transfer files with encryption applied from the moment the connection opens.
Is port 989 TCP or UDP?
Port 989 (FTPS-DATA) uses TCP.
Is port 989 secure?
Yes. Port 989 carries encrypted traffic by default, so data in transit is protected.
Should I open port 989 on my firewall?
Only if you specifically need FTPS-DATA. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.