IPv6 Essentials, 3rd Edition

Preface

This book is about the next-generation Internet Protocol. We have become familiar with the strengths and weaknesses of IPv4; we know how to design and configure it, and we have learned how to troubleshoot it. And now we have to learn a new protocol? Start from scratch? Not really. The designers of IPv6 have learned a lot from over 15 years of experience with IPv4, and they have been working on the new protocol since the early 1990s. They retained the strengths of IPv4, extended the address space from 32 bits to 128 bits, and added functionality that is missing in IPv4. They developed transition mechanisms that make IPv4 and IPv6 coexist peacefully and that guarantee a smooth transition between the protocols. In fact, this was one of the major requirements for the development of the new protocol version.

So you do not need to forget what you know about IPv4; many things will feel familiar with IPv6. When you get started, you will discover new features and functionalities that will make your life a lot easier. IPv6 has features that you will need in tomorrow’s networks—features that IPv4 does not provide.

One of the cool features built into IPv6 is the Stateless Autoconfiguration capability. Haven’t we always struggled with IP address assignment? The advent of DHCP made our lives easier, but now we need to maintain and troubleshoot DHCP servers. And when our refrigerator, swimming pool, and heating system as well as our smartphones and the TV set each have IP addresses, will we need a DHCP server at home? Not with Stateless Autoconfiguration. If you have an IPv6-enabled host, you can plug it into your network, and it will configure automatically for a valid IPv6 address. ICMP (Internet Control Message Protocol), which is a networker’s best friend, has become much more powerful with IPv6. Many of the new features of IPv6, such as Stateless Autoconfiguration, optimized multicast routing and multicast group management, Neighbor Discovery, Path MTU Discovery, and Mobile IPv6, are based on ICMPv6.

I hope that this book will help you to become familiar with the protocol and provide an easy-to-understand entry point and guide to exploring this new area.

Audience

This book covers a broad range of information about IPv6 and is an excellent resource for anybody who wants to understand or implement the protocol. It is also a good read for people who develop applications. IPv6 offers functionality that we did not have with IPv4, so it may open up new possibilities for applications. Whether you are the owner or manager of a company or an IT department; whether you are a system or network administrator, an engineer, or a network designer; or whether you are just generally interested in learning about the important changes with IPv6, this book discusses economic and strategic aspects as well as technical details. I describe interoperability mechanisms and scenarios that ensure a smooth introduction of IPv6. If you are a company owner or manager, you will be most interested in Chapters 7 and 9. If you need to plan your corporate network strategy, you will be most interested in Chapters 1, 4, 5, 7, and 9. If you manage the infrastructure in your company, you will especially be interested in Chapters 4 and 5, which cover ICMPv6, Layer 2 issues, and routing, and in Chapters 7 and 9, which address transition mechanisms, interoperability, and planning. If you are a system or network administrator, all chapters are relevant: this book provides a foundation for IPv6 implementation and integration with IPv4.

About This Book

This book covers IPv6 in detail and explains all the new features and functions. It will show you how to plan for, design, and integrate IPv6 in your current IPv4 infrastructure.

This book assumes that you have a good understanding of network issues in general and a familiarity with IPv4. It is beyond the scope of this book to discuss IPv4 concepts in detail. I refer to them when necessary, but if you want to learn more about IPv4, there are a lot of good resources on the market. You can find a list of books in Appendix B.

In explaining all the advanced features of IPv6, this book aims to inspire you to rethink your networking and service concepts for the future and create the foundation for a real nex-generation network.

Organization

This book is organized so that a reader familiar with IPv4 can easily learn about the new features in IPv6 by reading Chapters 2 through 7. These chapters cover what you need to know about addressing, the new IPv6 header, ICMPv6, Layer 2, routing protocols, DNS and DHCPv6, security, Quality of Service (QoS), and the transition mechanisms that make IPv6 work with IPv4 in different stages of transition. Mobile IPv6 is discussed in Chapter 8. Chapter 9 covers the planning process and considerations to make, and puts all the technical pieces together. Here is a chapter-by-chapter breakdown of the book:

• Chapter 1, Why IPv6?, briefly explains the history of IPv6 and gives an overview of the new functionality. It draws a bigger picture of Internet and service evolution, showing that the large address space and the advanced functionality of IPv6 are much needed for different reasons. It then discusses the most common misconceptions that prevent people from exploring and integrating the protocol. Finally, it explains when it would be the right moment for you to start your IPv6 project and drive the integration.
• Chapter 2, IPv6 Addressing, explains everything you need to know about the new address architecture, the address format, address notation, address types, international registry services, and prefix allocation.
• Chapter 3, The Structure of the IPv6 Protocol, describes the new IPv6 header format with a discussion of each field and trace file examples. It also describes what Extension headers are, what types of Extension headers have been defined, and how they are used.
• Chapter 4, ICMPv6, describes the new ICMPv6 message format, the ICMPv6 Error messages and Informational messages, and the ICMPv6 header in the trace file. This chapter also discusses the extended functionality based on ICMPv6, such as Neighbor Discovery, Autoconfiguration, Path MTU Discovery, and Multicast Listener Discovery (MLD). You will learn how ICMPv6 makes an administrator’s life easier.
• Chapter 5, Networking, covers several network-related aspects and services, such as Layer 2 support for IPv6, Upper Layer Protocols and Checksums, an overview of all multicast-related topics, an overview of routing protocols, Quality of Service (QoS), DHCPv6, and DNS.
• Chapter 6, Security with IPv6, begins with a short discussion of basic security concepts and requirements. It then covers the IPsec framework, security elements available in IPv6 for authentication and encryption, and how they are used. Our future networks will require new security architectures. This chapter provides an overview of considerations to make when defining the IPv6 security concept.
• Chapter 7, Transition Technologies, discusses the different transition mechanisms that have been defined, such as dual-stack operation and different tunneling, and translation techniques. It also shows how they can be used and combined to ensure peaceful coexistence and smooth transition. This is your toolkit to plan a cost- and labor-efficient transition.
• Chapter 8, Mobile IPv6, covers Mobile IPv6. This chapter explains why this technology could become the foundation for a new generation of mobile services. It also shows how the Extension header support of IPv6 can provide functionality that IPv4 can’t.
• Chapter 9, Planning for IPv6, puts it all together in a big picture. It discusses the planning process, success criteria, integration scenarios, best practices, and a summary of do’s and don’ts based on my long-time consulting experience.
• Appendix A, includes a short introduction to the RFC process and authorities, and provides a list of relevant RFCs for IPv6.
• Appendix B, provides a list of books that I recommend.

Note

Some important topics and information appear in multiple places in the book. This is not because I want to bore you, but because I assume that most readers will not read the book from the first page to the last page, but rather will pick and choose chapters and sections depending on interest. So if the information is important with regard to different sections and contexts, I may mention it again.

Conventions Used in This Book

The following typographical conventions are used in this book:

Italic

Indicates new terms, URLs, email addresses, filenames, and file extensions.

Constant width

Used for program listings, as well as within paragraphs to refer to program elements such as variable or function names, databases, data types, environment variables, statements, and keywords.

Constant width bold

Shows commands or other text that should be typed literally by the user.

Constant width italic

Shows text that should be replaced with user-supplied values or by values determined by context.

Tip

This element signifies a tip or suggestion.

Note

This element signifies a general note.

Warning

This element indicates a warning or caution.

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Acknowledgments

There are many people all over the world who have contributed to this book. Without their help and input, it would not be what it is.

For the first edition: many thanks go out to Anja Spittler (Maggy). She spent hours, days, and weeks in our lab in the early days of IPv6, setting up SuSE Linux, getting BIND and other services to work, and writing parts of Chapters 9 and 12 in the first edition. I also want to thank the technical editors, who have made this book much better with their invaluable comments, corrections, and clarifications. They were great resources when I was struggling with a topic and needed some answers. The technical reviewers of the first edition were Patrick Grossetete, who worked as a product manager for the Internet Technology Division (ITD) at Cisco, and Neil Cashell, who is a great TCP/IP guy at Novell, today SuSE. Thanks also to Brian McGehee, who has been working with IPv6 for many years and has written numerous courses for IPv6. He did the final technical edits of the first edition and added a lot of useful information. I’d like to thank Cisco Switzerland, especially René Räber, both for providing an updated router and access to their technical resources, as well as for his support of my work for IPv6. Thanks to the guys at SuSE for providing software and supporting us in getting our SuSE host ready for IPv6; Microsoft for providing software and information about their implementations; Network General for providing Sniffer Pro Software for the trace files; Bob Fink for running the 6Bone website; Cricket Liu for answering my DNS questions; and Peter Bieringer for running a great Internet resource site and for answering my questions with lightning speed.

There were many additional supporters, writers, and reviewers for the second edition. They include: Jim Bound from HP, CTO of the IPv6 Forum and Chair of the NAv6TF; Latif Ladid, President of the IPv6 Forum; Tim Chown, Department of Electronics and Computer Science at the University of Southampton; and Vijayabhaskar from McAfee. Yurie Rich, John Spence, and Mike Owen from Native6 Inc. in Seattle provided substantial input into Chapters 1, 5, 6, and 10 of the second edition. Gene Cronk from the Robin Shepherd Group gave substantial input into Chapters 5 and 10, and John Jason Brzozowski, North American IPv6 Task Force and Chair of the Mid-Atlantic IPv6 Task Force, contributed great input into Chapters 1 and 9. Thanks to David B. Green from SRI International for the permission to quote his Enterprise Security Model presentation in Chapter 5 and for reviewing different parts of the book. Thanks to Merike Kaeo, Chief Network Security Architect at Double Shot Security, for all her inputs and comments to Chapter 5. And thanks to Chris Engdahl from Microsoft for his review of Chapter 10. Thanks to Jimmy Ott from Sunny Connection for researching and writing all updates for Chapter 12. David Malone, author of the companion book IPv6 Network Administration, reviewed the whole book—thank you, David, for your great and clarifying comments. A great thank you goes out to all the people who were ready to share their experience with me and have provided case studies. They are Paolo Vieira from the University of Porto, Pierre David from the University of Strasbourg, Cody Christman from NTT Communications, and Flavio Curti and Ueli Heuer from Cyberlink AG in Zurich. Wolfgang Fritsche from IABG Germany and Karim El-Malki from Ericsson AB in Stockholm reviewed and provided input on Chapter 8 about Mobility. Thanks to the people at Checkpoint for providing information and connections, especially Patrik Honegger and Yoni Appel; and thanks also to Jean-Marc Uzé at Juniper for his information and connections. I also want to thank all the people and developers in the international working groups. Without their visionary power, enthusiasm, and tireless work, we would not have IPv6 ready.

I would like to honor Jim Bound, mentioned in the acknowledgments for the second edition. He was the key developer and driver of IPv6 for many years. He was the CTO of the International IPv6 Forum and a member of the IETF (Internet Engineering Task Force) IP Next Generation directorate. Without his drive, knowledge, and passion, IPv6 would not be where it is today. Unfortunately, Jim left this world way too early in 2009 at the age of 58. In honor of Jim, the International IPv6 Forum has created the Jim Bound Award, which is given to countries for World Leadership in IPv6 Deployment. I was honored to receive the first Jim Bound Award for the Swiss IPv6 Council, for Switzerland being the first country in the world reaching a double-digit IPv6 user penetration rate in April of 2013.

For this third edition, I was happy to have many great and knowledgeable helpers.

First of all, I would like to thank my three main reviewers who reviewed all chapters. They are Ed Horley, David Malone, and Niall Murphy. Thank you guys for your great inputs, your thoughts, and inspirations, and for taking the time to do this and answer my questions. Ed Horley is also the author of Practical IPv6 for Microsoft Administrators, a must-read for all who deal with Microsoft operating systems. I would like to thank Mark Townsley, Cameron Byrne, and Jan Zorz for reviewing and providing important input to Chapters 7 and 9, Chip Popoviciu for writing the MPLS section, Gerd Pflüger for writing the LISP section, and Eric Vyncke for his inputs and review of Chapter 6. I would also like to thank Jasper Bongertz, my network analysis guru and IPv6 trainer, for helping with Wireshark cosmetics, and Uwe Lenz, my second IPv6 instructor. He created an awesome lab for my hands-on class and used it to create all sorts of trace files for this book. Thanks to Andrew Yourtchenko and Gert Döring for responding to my many questions and to Jeff Carrell for many interesting discussions about the inner workings of SLAAC and the subtleties of what we see in trace files. I would also like to thank Bea Leonhardt for managing my office when I was writing and for help with updating the RFC lists. And Robin Huber for being an enthusiastic IT guy helping me with my infrastructure, solving my PC issues, taking care of the logistics at our IPv6 conferences, and for updating me on the latest gaming devices. And last but not least, Latif Ladid for all his continuing work for the IPv6 community, for cheering me up when working on weekends, and for getting Vint Cerf on board for the foreword.

And to all the great people at O’Reilly: for the first edition, a special thank you goes to Jim Sumser, Mike Loukides, and Tatiana Apandi. Jim Sumser guided me through the whole writing process of the first edition with a lot of enthusiasm, patience, and experience. Thank you, Jim, for being there, and thank you for never hassling me when I was already struggling. You made a difference! Mike and Tatiana, with whom I worked on the second edition, have also been very supportive throughout the whole process. I also want to thank all the other folks at O’Reilly who contributed to this book, especially Tim O’Reilly for making it possible in the first place. For this third edition, I was mostly working with Meghan Blanchette. Meghan, I thank you for all your great work, your support, your humor, and your patience with my crazy schedule. You were always there when I reached out and helped me stay on track.

Another very special thank you goes to Hanspeter Bütler, who was my teacher back in school, for teaching me the beauty of the ancient Greek language. His insightful and sensitive way of guiding me into understanding and feeling the richness of old languages laid the foundation for my understanding of language in general, of different cultures and how the differences in viewing the world are expressed in language. I can probably make him partially responsible for my becoming an author. Language is made to communicate, and the more precisely we use our language, the better we can understand and be understood. Without communication, there can be no understanding. On a different level, TCP/IP is the protocol that enables communication in the network and therefore creates the foundation for Internet communication. And the Internet creates the physical foundation for global communication. It offers a great opportunity to communicate, share, and understand globally across all cultures. That is how we should be using it.