Introduction

The Intermediate System-to-Intermediate System (IS-IS) Routing Protocol is a versatile and robust routing protocol suitable for both IP and CLNP applications. In the IP world, it has emerged as the only practical alternative to the Open Shortest Path First Protocol for Interior Gateway Protocol (IGP) applications in Internet Service Provider (ISP) networks. IS-IS is the IGP of choice in most tier one ISP environments and its significance certainly explains why it features in the CCIE Routing and Switching, as well as the CCIE IP recertification exams. Despite the importance of IS-IS in IP networking, it has received little coverage in the technical press and networking literature. Most users and networking professionals rely on scanty literature and the configuration manuals from Cisco and other major router vendors to boost their knowledge on IS-IS. Many routing protocol texts from Cisco Press cover IS-IS in sections, yet OSPF is covered in many book titles. This first book title on IS-IS breaks tradition of inadequate IS-IS coverage by focusing primarily on IS-IS. IS-IS Network Design Solutions follows the much-cherished Cisco Press approach of combining theory and practice within the setup of the Cisco Routing environment. The text also includes elaborate comparison with its competitor, OSPF.