This white paper describes the implementation of the TCP/IP protocol stack in the Microsoft® Windows Server™ 2003 family and is a supplement to the Windows Server 2003 Help and Support Center and Technical Reference documentation. This white paper contains an overview of TCP/IP in Windows Server 2003 features and capabilities, a discussion of protocol architecture, and detailed discussions of the core components, network application interfaces, and critical client components and services. The intended audience for this paper is network engineers and support professionals who are already familiar with TCP/IP. Except where noted, the TCP/IP implementation for Windows® XP is the same as that for Windows Server 2003.