All ports
Port1903/UDP
linknamePort
1903
Protocol
UDP
Category
Registered
Service
linkname
What is port 1903?
Port 1903/UDP is a Registered port, registered with IANA for specific applications. It is associated with the linkname service.
Local Link Name Resolution
Useful commands
nmapnmap -p 1903 -sV example.comnetcatnc -zv example.com 1903curlcurl -v http://example.com:1903/telnettelnet example.com 1903bash(echo > /dev/udp/example.com/1903) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 1903/udpDeny
sudo ufw deny 1903/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 1903 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 1903 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=1903/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 1903" dir=in action=allow protocol=UDP localport=1903Security 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- Outdated versions with vulnerabilities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 1903/UDP?
Port 1903/UDP is associated with the linkname service. Local Link Name Resolution
Is it safe to expose port 1903 to the Internet?
It depends on the service and configuration. Port 1903 (linkname) 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 1903 is open?
You can use nmap: `nmap -p 1903 -sV example.com`, netcat: `nc -zv example.com 1903`, or the bash command: `(echo > /dev/udp/example.com/1903) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 1903 on my firewall?
On Linux with UFW: `sudo ufw allow 1903/udp` (open) or `sudo ufw deny 1903/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 1903 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 1903" dir=in action=allow protocol=UDP localport=1903`.
What applications and services use port 1903?
Port 1903/UDP is used by the linkname service. Specific uses depend on the software and configuration. Check our related tools section for more information.