Port 3269: Global Catalog SSL
Port 3269 is the Global Catalog port encrypted with TLS, the secure counterpart to port 3268. Applications use it to query Active Directory objects across an entire forest without sending the query in clear text.
| Port number | 3269 |
|---|---|
| Service | Global Catalog over SSL/TLS |
| Protocol | TCP |
| Category | Windows |
| Default encryption | Yes (TLS/SSH) |
How do I check whether port 3269 is open?
Port 3269 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.
| Question | Command | What to know |
|---|---|---|
| Is it open on a remote host? | nc -vz example.com 3269 | A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line. |
| Same check on Windows | Test-NetConnection example.com -Port 3269 | Built 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 ':3269 ' | Lists the process bound to port 3269 on Linux. On macOS use lsof -nP -iTCP:3269 -sTCP:LISTEN, on Windows netstat -ano | findstr :3269 |
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 3269 used for?
Port 3269 is the Global Catalog port encrypted with TLS, the secure counterpart to port 3268. Applications use it to query Active Directory objects across an entire forest without sending the query in clear text.
Is port 3269 TCP or UDP?
Port 3269 (Global Catalog SSL) uses TCP.
Is port 3269 secure?
Yes. Port 3269 carries encrypted traffic by default, so data in transit is protected.
Should I open port 3269 on my firewall?
Only if you specifically need Global Catalog SSL. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.