All ports
Port3131/UDP
netbookmarkPort
3131
Protocol
UDP
Category
Registered
Service
netbookmark
What is port 3131?
Port 3131/UDP is a Registered port, registered with IANA for specific applications. It is associated with the netbookmark service.
Net Book Mark
Useful commands
nmapnmap -p 3131 -sV example.comnetcatnc -zv example.com 3131curlcurl -v http://example.com:3131/telnettelnet example.com 3131bash(echo > /dev/udp/example.com/3131) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3131/udpDeny
sudo ufw deny 3131/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 3131 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 3131 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3131/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3131" dir=in action=allow protocol=UDP localport=3131Security 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- Outdated versions with vulnerabilities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 3131/UDP?
Port 3131/UDP is associated with the netbookmark service. Net Book Mark
Is it safe to expose port 3131 to the Internet?
It depends on the service and configuration. Port 3131 (netbookmark) 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 3131 is open?
You can use nmap: `nmap -p 3131 -sV example.com`, netcat: `nc -zv example.com 3131`, or the bash command: `(echo > /dev/udp/example.com/3131) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3131 on my firewall?
On Linux with UFW: `sudo ufw allow 3131/udp` (open) or `sudo ufw deny 3131/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 3131 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3131" dir=in action=allow protocol=UDP localport=3131`.
What applications and services use port 3131?
Port 3131/UDP is used by the netbookmark service. Specific uses depend on the software and configuration. Check our related tools section for more information.