Port 16666
vtp · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | vtp |
| Registered | 2011-10-24 |
Frequently asked questions
What is port 16666 used for?
Port 16666 is registered with the IANA for vtp (TCP/UDP). Description: Reserved; Vidder Tunnel Protocol.
Is port 16666 a well-known port?
No. Port 16666 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 16666 is open?
Locally on Linux with ss -tulpn | grep ':16666\b', on Windows with netstat -ano | findstr :16666. To test a remote host use Test-NetConnection <host> -Port 16666 in PowerShell or nc -zv <host> 16666 on Linux/macOS.
How do I open port 16666 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 16666/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=16666/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 16666" -Direction Inbound -Protocol TCP -LocalPort 16666 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | – | Reserved |
| UDP | vtp | Vidder Tunnel Protocol |