參考 (O&O Defrag 的 FAQ 之一)

The communication between the components of O&O Defrag (e.g. the Agent and the GUI) is based on TCP/IP. This communication takes place only internally, and doesn't access the internet. However, most firewalls are programmed to recognize internal IP communication, so you receive a warning message.
You don't have to turn off your firewall! Simply open up port 50300. Since O&O Defrag automatically checks access privileges, there can be no external access over this port even if you are connected to the internet.