Windows 8 In Depth

Firewalls and NAT (Connection-Sharing) Devices

Using a firewall is an effective way to secure your network. From the viewpoint of design and maintenance, it is also the most efficient tool because you can focus your efforts on one critical place—the interface between your internal network and the Internet.

A firewall is a program or piece of hardware that intercepts all data that passes between two networks—for example, between your computer or LAN and the Internet. The firewall inspects each incoming and outgoing data packet and permits only certain packets to pass. Generally, a firewall is set up to permit traffic for safe protocols such as those used for email and web browsing. It blocks packets that carry file-sharing or computer administration ...