All ports
Port3431/UDP
ndl-alsPort
3431
Protocol
UDP
Category
Registered
Service
ndl-als
What is port 3431?
Port 3431/UDP is a Registered port, registered with IANA for specific applications. It is associated with the ndl-als service.
Active License Server Port
Useful commands
nmapnmap -p 3431 -sV example.comnetcatnc -zv example.com 3431curlcurl -v http://example.com:3431/telnettelnet example.com 3431bash(echo > /dev/udp/example.com/3431) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3431/udpDeny
sudo ufw deny 3431/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 3431 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 3431 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3431/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3431" dir=in action=allow protocol=UDP localport=3431Security 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- Outdated versions with vulnerabilities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 3431/UDP?
Port 3431/UDP is associated with the ndl-als service. Active License Server Port
Is it safe to expose port 3431 to the Internet?
It depends on the service and configuration. Port 3431 (ndl-als) 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 3431 is open?
You can use nmap: `nmap -p 3431 -sV example.com`, netcat: `nc -zv example.com 3431`, or the bash command: `(echo > /dev/udp/example.com/3431) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3431 on my firewall?
On Linux with UFW: `sudo ufw allow 3431/udp` (open) or `sudo ufw deny 3431/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 3431 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3431" dir=in action=allow protocol=UDP localport=3431`.
What applications and services use port 3431?
Port 3431/UDP is used by the ndl-als service. Specific uses depend on the software and configuration. Check our related tools section for more information.