Overview of Windows Firewall

All newer Windows operating systems, by default enable the Windows Firewall to block virtually all TCP network ports to the incoming connections.

As a result, any Oracle products that listen for incoming connections on a TCP port do not receive any of those connection requests, and the clients making those connections report errors.

Depending upon which Oracle products are installed and how they are used, the products require some postinstallation configuration of the Windows Firewall to function on these operating systems.