Port 3321
vnsstr · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | vnsstr |
Frequently asked questions
What is port 3321 used for?
Port 3321 is registered with the IANA for vnsstr (TCP/UDP). Description: VNSSTR.
Is port 3321 a well-known port?
No. Port 3321 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 3321 is open?
Locally on Linux with ss -tulpn | grep ':3321\b', on Windows with netstat -ano | findstr :3321. To test a remote host use Test-NetConnection <host> -Port 3321 in PowerShell or nc -zv <host> 3321 on Linux/macOS.
How do I open port 3321 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 3321/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=3321/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 3321" -Direction Inbound -Protocol TCP -LocalPort 3321 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | vnsstr | VNSSTR |
| UDP | vnsstr | VNSSTR |