The following Network Diagram is designed using free symbols that are readily available at EdrawMax. As the diagram illustrates, GCI is a fictional company providing business services to various clients across many industries. As shown, GCI's network uses a conventional three-zone architecture: devices exposed to the internet are part of an un-trusted outer zone; internet-accessible services such as the company website; and major systems and servers supporting both internet-facing and internal applications as well as internal computing resources such as the corporate LAN is in a trusted zone. IT should be noted here that each of these zones is segmented from the others using a hardware-based firewall, and the corporate databases are further protected behind their own dedicated firewall.
