All ports
Port5721/UDP
dtptPort
5721
Protocol
UDP
Category
Registered
Service
dtpt
What is port 5721?
Port 5721/UDP is a Registered port, registered with IANA for specific applications. It is associated with the dtpt service.
Desktop Passthru Service
Useful commands
nmapnmap -p 5721 -sV example.comnetcatnc -zv example.com 5721curlcurl -v http://example.com:5721/telnettelnet example.com 5721bash(echo > /dev/udp/example.com/5721) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 5721/udpDeny
sudo ufw deny 5721/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 5721 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 5721 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=5721/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 5721" dir=in action=allow protocol=UDP localport=5721Security 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- Outdated versions with vulnerabilities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 5721/UDP?
Port 5721/UDP is associated with the dtpt service. Desktop Passthru Service
Is it safe to expose port 5721 to the Internet?
It depends on the service and configuration. Port 5721 (dtpt) 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 5721 is open?
You can use nmap: `nmap -p 5721 -sV example.com`, netcat: `nc -zv example.com 5721`, or the bash command: `(echo > /dev/udp/example.com/5721) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 5721 on my firewall?
On Linux with UFW: `sudo ufw allow 5721/udp` (open) or `sudo ufw deny 5721/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 5721 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 5721" dir=in action=allow protocol=UDP localport=5721`.
What applications and services use port 5721?
Port 5721/UDP is used by the dtpt service. Specific uses depend on the software and configuration. Check our related tools section for more information.