Port 517: Talk
Port 517 is the Talk protocol, a Unix utility that let two users chat in real time in a split-screen text window. It has been replaced by modern messaging tools and is rarely run today.
UDPLegacy protocolsUnencrypted by defaultIANA assigned
| Port number | 517 |
|---|---|
| Service | Talk protocol |
| Protocol | UDP |
| Category | Legacy protocols |
| Default encryption | No |
Security note. Port 517 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.
Frequently asked questions
What is port 517 used for?
Port 517 is the Talk protocol, a Unix utility that let two users chat in real time in a split-screen text window. It has been replaced by modern messaging tools and is rarely run today.
Is port 517 TCP or UDP?
Port 517 (Talk) uses UDP.
Is port 517 secure?
Port 517 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 517 on my firewall?
Only if you specifically need Talk. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.