本书系统介绍了虚拟专用网的概念、起源、配置、实现和维护，还对虚拟专用网体系结构、加密工具、有关限制、防火墙结构等内容进行了探讨，并提供了大量实例。本书是网络、MIS管理员必备的参考书。 -System, this book introduces the concept of virtual private network, the origin, configuration, implementation, and maintenance, but also on the virtual private network architecture, encryption tools, the restrictions on the content of the firewall structure was discussed and to provide a large number of examples. This book is the network, MIS managers must have reference book.