Over the years, many excellent books have been written on IP technology, and these books tend to focus on a specific topic, such as Open Shortest Path First (OSPF) or Border Gateway Protocol (BGP). However, building a resilient IP network requires a holistic approach to design and implementation. Various building blocks need to work together, most of which have seen enhancements and new features introduced. These features are scattered, mostly in the form of numerous Requests For Comments (RFCs), IOS features and documentations, and many Cisco Technical Assistance Center (TAC)-authored white papers. The goal of this book is to provide a central resource for the features that focus on IP network resiliency. It covers a wide range of topics and serves as a foundation for anyone who needs a deeper understanding about IP network resiliency. ### Who Should Read This Book? This book is intended to increase your knowledge with respect to improving the resiliency of an IP network. It is not meant to be an introduction to IP network design. This book helps you understand what network availability means and introduces new features and tools that have been developed to improve resiliency in IP networks. Anyone who is involved in the design and implementation of a large-scale IP network and would like to understand ways to improve its resiliency will benefit from this book. ### How This Book Is Organized Although this book could be read cover to cover, it is designed to be flexible. You can easily move between chapters and sections of chapters to cover just the material that you need more information on. • **[Chapter 1](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch01.html#ch01), “[Rise of the IP Transport System](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch01.html#ch01),”** provides a backdrop to the usage and new expectations of the IP network. • **[Chapter 2](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch02.html#ch02), “[Establishing a High-Availability Network](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch02.html#ch02),”** takes a closer look at the real meaning of network resiliency and suggests a practical approach to tackling the “five-nines” availability challenge. • **[Chapter 3](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch03.html#ch03), “[Fundamentals of IP Resilient Networks](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch03.html#ch03),”** serves as a refresher to the TCP/IP protocols and the various hardware and switching implementations that affect network resiliency. It also proposes a modular approach to solving the network resiliency problem. • **[Chapter 4](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch04.html#ch04), “[Quality of Service](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch04.html#ch04),”** examines the relevancy of quality of service (QoS) with respect to network resiliency. Different QoS models and queuing techniques are examined, and a practical approach to a QoS architecture is presented. • **[Chapter 5](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch05.html#ch05), “[Core Module](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch05.html#ch05)”** examines the enhancements made to the various Interior Gateway Protocols to improve the resiliency of a network backbone. • **[Chapter 6](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch06.html#ch06), “[Access Module](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch06.html#ch06),”** showcases the design guide for a resilient campus access network. Enhancements to the relevant protocol and first-hop gateways are highlighted. • **[Chapter 7](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch07.html#ch07), “[Internet Module](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch07.html#ch07),”** focuses on resilient connectivity to the Internet. Improvements to the Exterior Gateway Protocol and addressing and routing solutions for redundancy are highlighted. • **[Chapter 8](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch08.html#ch08), “[WAN Module](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch08.html#ch08),”** showcases improvements made to the various traditional WAN connectivity technologies. • **[Chapter 9](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch09.html#ch09), “[Data Center Module](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch09.html#ch09),”** examines factors that influence data center network design. It highlights new technologies and a design guide to constructing the data center to support new application requirements. • **[Chapter 10](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch10.html#ch10), “[Beyond Implementation: Network Management](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/ch10.html#ch10),”** looks at what more needs to be done beyond the basic configuration of hardware and routing protocols in a resilient IP network. The concept of proactive management is proposed, and the various supporting features are introduced. • **[Appendix A](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/app01.html#app01), “[Calculating Network Availability](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/app01.html#app01),”** discusses mathematical calculations to evaluate network availability. • **[Appendix B](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/app02.html#app02), “[RFCs Relevant to Building a Resilient IP Network](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/app02.html#app02),”** lists RFCs that are relevant to building resilient IP networks. • **[Appendix C](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/app03.html#app03), “[The Cisco Powered Network Checklist](https://learning.oreilly.com/library/view/building-resilient-ip/1587052156/app03.html#app03),”** is an extract from the Cisco Powered Network data center best practices checklist.