This is an option that will enable you to limit how much your service is exposed to attacks from the public network. The Firewall Network protects the IPs that are associated with a machine. You must therefore configure each IP separately; it is not possible to configure the server as a whole. You can enable and configure it manually from the Control Panel in the IP section, by clicking on the gear icon to the right of the relevant IPv4. The firewall is enabled automatically upon each DDoS attack, and cannot be disabled before the attack ends. This is why it is important to keep the firewall rules up to date. As a default setting you do not have any configured rules, so all connections can be set up. If you do have any, remember to check your firewall rules regularly, even if you disable it. The rules are sorted chronologically from 0 the first rule read to 19 the last. The chain stops being scanned as soon as a rule is applied to the packet.
How to set up and package a dedicated server for your project.
Networking Overview. Client-Server Model. Multiplayer Programming Quick Start.