All ports
Port3999/TCP
nvcnetPort
3999
Protocol
TCP
Category
Registered
Service
nvcnet
What is port 3999?
Port 3999/TCP is a Registered port, registered with IANA for specific applications. It is associated with the nvcnet service.
Norman distributes scanning service
Useful commands
nmapnmap -p 3999 -sV example.comnetcatnc -zv example.com 3999curlcurl -v http://example.com:3999/telnettelnet example.com 3999bash(echo > /dev/tcp/example.com/3999) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3999/tcpDeny
sudo ufw deny 3999/tcpiptablesAllow
sudo iptables -A INPUT -p tcp --dport 3999 -j ACCEPTDeny
sudo iptables -D INPUT -p tcp --dport 3999 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3999/tcpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3999" dir=in action=allow protocol=TCP localport=3999Security 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- Outdated versions with vulnerabilities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 3999/TCP?
Port 3999/TCP is associated with the nvcnet service. Norman distributes scanning service
Is it safe to expose port 3999 to the Internet?
It depends on the service and configuration. Port 3999 (nvcnet) 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 3999 is open?
You can use nmap: `nmap -p 3999 -sV example.com`, netcat: `nc -zv example.com 3999`, or the bash command: `(echo > /dev/tcp/example.com/3999) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3999 on my firewall?
On Linux with UFW: `sudo ufw allow 3999/tcp` (open) or `sudo ufw deny 3999/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 3999 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3999" dir=in action=allow protocol=TCP localport=3999`.
What applications and services use port 3999?
Port 3999/TCP is used by the nvcnet service. Specific uses depend on the software and configuration. Check our related tools section for more information.