WINDOWS Vista is Microsoft’s much anticipated new client operating system. When released, it is due to replace Windows XP as Microsoft’s premier desktop operating system. Windows Vista represents a significant departure from previous Windows systems both in terms of its emphasis on security and its many new features. As security has grown in importance, Microsoft has paid increasingly more attention to it, evidenced by the significant resource investment that has been made. Windows Vista provides Microsoft with its first opportunity to introduce security into the design process of the core operating system itself. Microsoft has also chosen Windows Vista as the platform on which to introduce many newly developed technologies.

The Windows Vista network stack is particularly interesting because many of its components are new. The TCP/IP network stack itself has been rewritten and is one of Vista’s largest departures from previous versions of Windows. The new stack was written to allow easier maintenance, important new performance enhancements, and improved stability [30]. It integrates support for IPv6 and IPv4 into a single network stack and provides IPv6 support in the default configuration for the first time in the history of Windows. Many other new protocols are implemented and supported in Vista, either as part of the network stack or as separate components of the Windows operating system. These new protocols support features such as topology discovery, server-less name resolution, and NAT traversal. Even SMB, one of Microsoft’s oldest technologies, received a revision with the introduction of the SMB2