All ports
Port16666/UDP
vtpPort
16666
Protocol
UDP
Category
Registered
Service
vtp
What is port 16666?
Port 16666/UDP is a Registered port, registered with IANA for specific applications. It is associated with the vtp service.
Vidder Tunnel Protocol
Useful commands
nmapnmap -p 16666 -sV example.comnetcatnc -zv example.com 16666curlcurl -v http://example.com:16666/telnettelnet example.com 16666bash(echo > /dev/udp/example.com/16666) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 16666/udpDeny
sudo ufw deny 16666/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 16666 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 16666 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=16666/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 16666" dir=in action=allow protocol=UDP localport=16666Security Risks
- Unauthorized access to the service
- Data exposure if the service is unauthenticated
- Outdated versions with vulnerabilities
- Incorrect service configuration
Frequently Asked Questions
What service runs on port 16666/UDP?
Port 16666/UDP is associated with the vtp service. Vidder Tunnel Protocol
Is it safe to expose port 16666 to the Internet?
It depends on the service and configuration. Port 16666 (vtp) is a Registered port. If you need to expose it, keep the service updated, use strong authentication, and configure a firewall. It's always recommended to restrict access by IP when possible.
How do I check if port 16666 is open?
You can use nmap: `nmap -p 16666 -sV example.com`, netcat: `nc -zv example.com 16666`, or the bash command: `(echo > /dev/udp/example.com/16666) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 16666 on my firewall?
On Linux with UFW: `sudo ufw allow 16666/udp` (open) or `sudo ufw deny 16666/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 16666 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 16666" dir=in action=allow protocol=UDP localport=16666`.
What applications and services use port 16666?
Port 16666/UDP is used by the vtp service. Specific uses depend on the software and configuration. Check our related tools section for more information.