Port 1921
noadmin · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | noadmin |
Frequently asked questions
What is port 1921 used for?
Port 1921 is registered with the IANA for noadmin (TCP/UDP). Description: NoAdmin.
Is port 1921 a well-known port?
No. Port 1921 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 1921 is open?
Locally on Linux with ss -tulpn | grep ':1921\b', on Windows with netstat -ano | findstr :1921. To test a remote host use Test-NetConnection <host> -Port 1921 in PowerShell or nc -zv <host> 1921 on Linux/macOS.
How do I open port 1921 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 1921/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=1921/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 1921" -Direction Inbound -Protocol TCP -LocalPort 1921 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | noadmin | NoAdmin |
| UDP | noadmin | NoAdmin |