Port 3690: Subversion

Port 3690 is the native svn protocol port for Subversion, used when a repository is accessed with an svn:// URL instead of over HTTP. It talks to the svnserve daemon directly.

TCPVersion controlUnencrypted by defaultIANA assigned
Port number3690
ServiceSubversion (svn) protocol
ProtocolTCP
CategoryVersion control
Default encryptionNo
Security note. Port 3690 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.

How do I check whether port 3690 is open?

Port 3690 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.

QuestionCommandWhat to know
Is it open on a remote host?nc -vz example.com 3690A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line.
Same check on WindowsTest-NetConnection example.com -Port 3690Built into PowerShell. TcpTestSucceeded in the output is the answer; telnet is not installed by default on modern Windows.
What is listening locally?ss -tlnp | grep ':3690 'Lists the process bound to port 3690 on Linux. On macOS use lsof -nP -iTCP:3690 -sTCP:LISTEN, on Windows netstat -ano | findstr :3690

Replace example.com with the host you are testing. A blocked port and a port with nothing listening on it look identical from the outside, so if a service should be running, check locally before blaming the firewall.

Frequently asked questions

What is port 3690 used for?

Port 3690 is the native svn protocol port for Subversion, used when a repository is accessed with an svn:// URL instead of over HTTP. It talks to the svnserve daemon directly.

Is port 3690 TCP or UDP?

Port 3690 (Subversion) uses TCP.

Is port 3690 secure?

Port 3690 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 3690 on my firewall?

Only if you specifically need Subversion. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.