This book provides a concise answer to how one should organize a robust enterprise IT infrastructure based on open-source software with mainstream hardware. It is a necessity for large organizations to build a central user - thentication service, global user information storage, and to offer common access to personal—les regardless of the location the user wishes to connect from. All these issues have been addressed with the help of well-established technologies such as the industry standard Kerberos for user authentication and the OpenAFS distributed—le system, originally conceived at CMU and used at universities like MIT and Stanford and also at research institutions like CERN among many others. Our presentation offers support for system architects and administrators, to decide and implement an enterprise IT infrastructure, and for advanced UNIX users wishing to look beyond isolated workstations, to experience the move from local to global administration and the resulting challenges. The presentation is a step-by-step guide, accompanied with a detailed explanation of thecorrespondingtechnicalcontextthatmirrorsourownexperiencegained during the setup of an AFS cell at our computer science and engineering department. The main focus lies on the application of UNIX-based services, with particular attention to the underlying OpenAFS—le system: therefore it can be seen as a companion to the excellent and currently only available book“ManagingAFS:TheAndrewFileSystem”byRichardCampbell,which reffects the new state of today’s implementation.