Port 513: rlogin
Port 513 is rlogin, an old remote-login protocol from the Berkeley r-commands suite that offers no encryption. SSH on port 22 replaced it because rlogin trusted the client's claimed identity far too easily.
TCPRemote accessUnencrypted by defaultIANA assigned
| Port number | 513 |
|---|---|
| Service | Remote login |
| Protocol | TCP |
| Category | Remote access |
| Default encryption | No |
Security note. Port 513 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 513 used for?
Port 513 is rlogin, an old remote-login protocol from the Berkeley r-commands suite that offers no encryption. SSH on port 22 replaced it because rlogin trusted the client's claimed identity far too easily.
Is port 513 TCP or UDP?
Port 513 (rlogin) uses TCP.
Is port 513 secure?
Port 513 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 513 on my firewall?
Only if you specifically need rlogin. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.