Port 749: kerberos-adm
Port 749 is the Kerberos administration port, used by admin tools to manage principals and policies on the Key Distribution Center. It is a privileged management channel and should be limited to admin hosts.
| Port number | 749 |
|---|---|
| Service | Kerberos administration |
| Protocol | TCP |
| Category | Authentication |
| Default encryption | No |
How do I check whether port 749 is open?
Port 749 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 749 | 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 749 | 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 ':749 ' | Lists the process bound to port 749 on Linux. On macOS use lsof -nP -iTCP:749 -sTCP:LISTEN, on Windows netstat -ano | findstr :749 |
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 749 used for?
Port 749 is the Kerberos administration port, used by admin tools to manage principals and policies on the Key Distribution Center. It is a privileged management channel and should be limited to admin hosts.
Is port 749 TCP or UDP?
Port 749 (kerberos-adm) uses TCP.
Is port 749 secure?
Port 749 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 749 on my firewall?
Only if you specifically need kerberos-adm. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.