All ports
Port517/TCP
talkPort
517
Protocol
TCP
Category
Well-Known
Service
talk
What is port 517?
Port 517/TCP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the talk service.
like tenex link, but across machine - unfortunately, doesn't use link protocol (this is actually just a rendezvous port from which a tcp connection is established)
Useful commands
nmapnmap -p 517 -sV example.comnetcatnc -zv example.com 517curlcurl -v http://example.com:517/telnettelnet example.com 517bash(echo > /dev/tcp/example.com/517) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 517/tcpDeny
sudo ufw deny 517/tcpiptablesAllow
sudo iptables -A INPUT -p tcp --dport 517 -j ACCEPTDeny
sudo iptables -D INPUT -p tcp --dport 517 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=517/tcpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 517" dir=in action=allow protocol=TCP localport=517Security 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- Outdated versions with vulnerabilities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 517/TCP?
Port 517/TCP is associated with the talk service. like tenex link, but across machine - unfortunately, doesn't use link protocol (this is actually just a rendezvous port from which a tcp connection is established)
Is it safe to expose port 517 to the Internet?
It depends on the service and configuration. Port 517 (talk) is a Well-Known 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 517 is open?
You can use nmap: `nmap -p 517 -sV example.com`, netcat: `nc -zv example.com 517`, or the bash command: `(echo > /dev/tcp/example.com/517) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 517 on my firewall?
On Linux with UFW: `sudo ufw allow 517/tcp` (open) or `sudo ufw deny 517/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 517 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 517" dir=in action=allow protocol=TCP localport=517`.
What applications and services use port 517?
Port 517/TCP is used by the talk service. Specific uses depend on the software and configuration. Check our related tools section for more information.