All ports
Port3901/UDP
nimshPort
3901
Protocol
UDP
Category
Registered
Service
nimsh
What is port 3901?
Port 3901/UDP is a Registered port, registered with IANA for specific applications. It is associated with the nimsh service.
NIM Service Handler
Useful commands
nmapnmap -p 3901 -sV example.comnetcatnc -zv example.com 3901curlcurl -v http://example.com:3901/telnettelnet example.com 3901bash(echo > /dev/udp/example.com/3901) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3901/udpDeny
sudo ufw deny 3901/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 3901 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 3901 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3901/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3901" dir=in action=allow protocol=UDP localport=3901Security 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- Outdated versions with vulnerabilities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 3901/UDP?
Port 3901/UDP is associated with the nimsh service. NIM Service Handler
Is it safe to expose port 3901 to the Internet?
It depends on the service and configuration. Port 3901 (nimsh) 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 3901 is open?
You can use nmap: `nmap -p 3901 -sV example.com`, netcat: `nc -zv example.com 3901`, or the bash command: `(echo > /dev/udp/example.com/3901) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3901 on my firewall?
On Linux with UFW: `sudo ufw allow 3901/udp` (open) or `sudo ufw deny 3901/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 3901 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3901" dir=in action=allow protocol=UDP localport=3901`.
What applications and services use port 3901?
Port 3901/UDP is used by the nimsh service. Specific uses depend on the software and configuration. Check our related tools section for more information.