All ports
Port3981/UDP
starfishPort
3981
Protocol
UDP
Category
Registered
Service
starfish
What is port 3981?
Port 3981/UDP is a Registered port, registered with IANA for specific applications. It is associated with the starfish service.
Starfish System Admin
Useful commands
nmapnmap -p 3981 -sV example.comnetcatnc -zv example.com 3981curlcurl -v http://example.com:3981/telnettelnet example.com 3981bash(echo > /dev/udp/example.com/3981) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3981/udpDeny
sudo ufw deny 3981/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 3981 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 3981 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3981/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3981" dir=in action=allow protocol=UDP localport=3981Security 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- Outdated versions with vulnerabilities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 3981/UDP?
Port 3981/UDP is associated with the starfish service. Starfish System Admin
Is it safe to expose port 3981 to the Internet?
It depends on the service and configuration. Port 3981 (starfish) 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 3981 is open?
You can use nmap: `nmap -p 3981 -sV example.com`, netcat: `nc -zv example.com 3981`, or the bash command: `(echo > /dev/udp/example.com/3981) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3981 on my firewall?
On Linux with UFW: `sudo ufw allow 3981/udp` (open) or `sudo ufw deny 3981/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 3981 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3981" dir=in action=allow protocol=UDP localport=3981`.
What applications and services use port 3981?
Port 3981/UDP is used by the starfish service. Specific uses depend on the software and configuration. Check our related tools section for more information.