This document describes a network security solution implementing Network Access Control (NAC) with Sophos NAC Advanced and Allied Telesis Switches. Sophos NAC Advanced is a sophisticated Network Access Control implementation that integrates tightly with other facilities on the Microsoft Server platform. The document provides step-by-step instructions for setting up Sophos NAC Advanced on a server running Microsoft Windows Server 2003 and configuring the Allied Telesis switch to work with this Sophos NAC implementation.