KMS Service Port 1688 Configuration and Firewall

KMS Service Port 1688 Configuration and Firewall

KMS client-server communication uses TCP port 1688. Ensure this port is open in both directions on the firewall between the KMS host and clients.

To verify the port is reachable:

telnet kms-server 1688
ping kms-server

Firewall rule on the KMS host (Windows Server):

netsh advfirewall firewall add rule name="KMS" dir=in action=allow protocol=TCP localport=1688

Reference: licensing guide