Port 9999
distinct · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | distinct |
Frequently asked questions
What is port 9999 used for?
Port 9999 is registered with the IANA for distinct (TCP/UDP). Description: distinct.
Is port 9999 a well-known port?
No. Port 9999 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 9999 is open?
Locally on Linux with ss -tulpn | grep ':9999\b', on Windows with netstat -ano | findstr :9999. To test a remote host use Test-NetConnection <host> -Port 9999 in PowerShell or nc -zv <host> 9999 on Linux/macOS.
How do I open port 9999 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 9999/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=9999/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 9999" -Direction Inbound -Protocol TCP -LocalPort 9999 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | distinct | distinct |
| UDP | distinct | distinct |