Port 6021
x11 · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | x11 |
Frequently asked questions
What is port 6021 used for?
Port 6021 is registered with the IANA for x11 (TCP/UDP). Description: X Window System.
Is port 6021 a well-known port?
No. Port 6021 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 6021 is open?
Locally on Linux with ss -tulpn | grep ':6021\b', on Windows with netstat -ano | findstr :6021. To test a remote host use Test-NetConnection <host> -Port 6021 in PowerShell or nc -zv <host> 6021 on Linux/macOS.
How do I open port 6021 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 6021/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=6021/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 6021" -Direction Inbound -Protocol TCP -LocalPort 6021 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | x11 | X Window System |
| UDP | x11 | X Window System |