All ports
Port1701/UDP
l2tpPort
1701
Protocol
UDP
Category
Registered
Service
l2tp
What is port 1701?
Port 1701/UDP is a Registered port, registered with IANA for specific applications. It is associated with the l2tp service.
l2tp
Useful commands
nmapnmap -p 1701 -sV example.comnetcatnc -zv example.com 1701curlcurl -v http://example.com:1701/telnettelnet example.com 1701bash(echo > /dev/udp/example.com/1701) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 1701/udpDeny
sudo ufw deny 1701/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 1701 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 1701 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=1701/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 1701" dir=in action=allow protocol=UDP localport=1701Security 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- Outdated versions with vulnerabilities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 1701/UDP?
Port 1701/UDP is associated with the l2tp service. l2tp
Is it safe to expose port 1701 to the Internet?
It depends on the service and configuration. Port 1701 (l2tp) 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 1701 is open?
You can use nmap: `nmap -p 1701 -sV example.com`, netcat: `nc -zv example.com 1701`, or the bash command: `(echo > /dev/udp/example.com/1701) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 1701 on my firewall?
On Linux with UFW: `sudo ufw allow 1701/udp` (open) or `sudo ufw deny 1701/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 1701 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 1701" dir=in action=allow protocol=UDP localport=1701`.
What applications and services use port 1701?
Port 1701/UDP is used by the l2tp service. Specific uses depend on the software and configuration. Check our related tools section for more information.