Port 9000: Alt-9000
Port 9000 has no single fixed meaning; it is used by PHP-FPM's FastCGI listener, the SonarQube code-quality dashboard, the Portainer container UI, and various other tools by convention rather than IANA assignment. Always check what is actually bound to it on a given host.
| Port number | 9000 |
|---|---|
| Service | Common alternate app port (PHP-FPM, SonarQube, Portainer) |
| Protocol | TCP |
| Category | Web |
| Default encryption | No |
How do I check whether port 9000 is open?
Port 9000 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 9000 | 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 9000 | 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 ':9000 ' | Lists the process bound to port 9000 on Linux. On macOS use lsof -nP -iTCP:9000 -sTCP:LISTEN, on Windows netstat -ano | findstr :9000 |
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 9000 used for?
Port 9000 has no single fixed meaning; it is used by PHP-FPM's FastCGI listener, the SonarQube code-quality dashboard, the Portainer container UI, and various other tools by convention rather than IANA assignment. Always check what is actually bound to it on a given host.
Is port 9000 TCP or UDP?
Port 9000 (Alt-9000) uses TCP.
Is port 9000 secure?
Port 9000 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 9000 on my firewall?
Only if you specifically need Alt-9000. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.