Introduction

As an escalation engineer, I experienced the boom of Multiprotocol Label Switching (MPLS) networking first hand. I saw the first trials of MPLS in service provider networks and saw MPLS successfully expanding further into enterprise networks. In addition, I witnessed new MPLS technologies coming into existence, which the networking industry embraced quickly. The first deployments of these new MPLS technologies were not always flawless, but they were always interesting.

The success of MPLS is undoubtedly a result of the fact that it enables the network to carry all kinds of traffic, ranging from IP traffic to Voice over IP (VoIP) traffic to Layer 2 traffic. MPLS is the means for an IP network to consolidate many networks into one. MPLS can consolidate the ATM, Frame Relay, Voice, and IP networks into one unified network infrastructure, thereby generating a huge cost advantage.

MPLS has matured a lot and is a stable technology, seeing many new deployments and new features. Given the fact that MPLS is based on IP, and the Internet is based on IP technology, it seems that the future of MPLS is ensured for quite a while to come.

Configuring MPLS on Cisco IOS is relatively simple, but much knowledge is needed to understand what to configure and how to troubleshoot when the MPLS network has problems. This book gives you this knowledge and highlights things from my own experience to warn you of pitfalls.

Goals and Methods

The purpose of this book is to make a network engineer a qualified MPLS network engineer. To accomplish this goal, this book starts by explaining the fundamentals of MPLS. It covers the principles and theory of MPLS thoroughly. It continues by explaining the MPLS applications that made MPLS so popular, including MPLS VPN, MPLS traffic engineering (TE), Any Transport over MPLS (AToM), and Virtual Private LAN Service (VPLS). The theory is accompanied by configuration examples, detailing how to implement and troubleshoot MPLS and its applications in Cisco IOS. When you have finished reading this book, you will have a comprehensive and useable MPLS knowledge. This book contains theory, Cisco IOS commands, and troubleshooting information so that you can deploy, administrate, design, and troubleshoot any MPLS network.

This book was written in a progressive manner, so if in doubt, read this book from beginning to end. That is the logical way of reading this book. Only the reader who already has some MPLS background should jump to any chapter and start reading it.

Who Should Read This Book?

This book lays down the fundamentals of the operation of MPLS and its deployment. As such, it introduces the networking professional to all facets of MPLS. I also tried to cover many MPLS applications and write down the things I learned and experienced the hard way. The aim of this book is to be both an introduction to MPLS for people who have had some networking experience but have not mastered MPLS yet and an opportunity to explain some of the more difficult and lesser-known aspects of MPLS. As such, this book can be used by network engineers, network administrators, network analysts, students, teachers, network managers, and network designers alike.

I tried to find a balance between theory and practical examples. The book was written with Cisco IOS in mind, and there are many configuration examples of Cisco IOS. However, even for the people who are not familiar with Cisco IOS, this book can be a great help in getting to understand MPLS thoroughly.

The reader should be familiar with IP and IP routing, because having a basic knowledge of those is a prerequisite to this book.

Finally, this book is especially useful to people who are preparing for the CCIE Service Provider written exam and the CCIE Service Provider lab exam, because they have a heavy emphasis on MPLS.

How This Book Is Organized

This book has 15 chapters and one appendix and is organized in two parts. Also available are online supplemental materials that you can find on the website, including an appendix on static MPLS labels.

Although each chapter has its own topic and stands alone, it is best to read this book in sequential order. Only if you are an MPLS-experienced reader will you be able to jump to any chapter from Part II without problem. Even if you fit into that category, you might want to browse through the chapters of Part I to refresh your memory and then proceed to Part II, which holds the chapters that require a thorough understanding of the MPLS fundamentals. If you cannot get enough of MPLS, you can find online supplements of Chapters 4, 7, 8, 9, and 10 at http://www.ciscopress.com/title/1587051974. Make sure you read the corresponding chapter in this book before reading the online chapter supplement. Appendix B, “Static MPLS Labels,” is available only on this website.

Part I, “Fundamentals of MPLS,” discusses how MPLS came about and explains its fundamentals.

• Chapter 1, “The Evolution of MPLS”— This chapter is an introduction to MPLS and how it came about. It also covers a brief overview of the most important applications of MPLS.

Chapters 2 through 6, on the fundamentals of MPLS, cover the following topics:

• Chapter 2, “MPLS Architecture”— This chapter focuses on the basic building blocks of MPLS.

• Chapter 3, “Forwarding Labeled Packets”— This chapter describes the label forwarding and the usage of the reserved MPLS labels.

• Chapter 4, “Label Distribution Protocol”— This chapter describes the Label Distribution Protocol (LDP) and how a router uses it to advertise MPLS labels.

• Chapter 5, “MPLS and ATM Architecture”— This chapter describes all the specifics of having an MPLS-enabled ATM network.

• Chapter 6, “Cisco Express Forwarding”— This chapter describes the Cisco Express Forwarding (CEF) architecture, which is a packet forwarding or switching method that Cisco IOS uses and MPLS needs.

Part II, “Advanced MPLS Topics,” covers the MPLS applications, quality of service (QoS), and troubleshooting:

• Chapter 7, “MPLS VPN”— This chapter discusses the most popular of all MPLS appications: MPLS VPN. It explains the complete architecture of MPLS VPN.

• Chapter 8, “MPLS Traffic Engineering”— This chapter looks at how traffic engineering (TE) is implemented with the MPLS technology.

• Chapter 9, “IPv6 over MPLS”— This chapter looks at how the IPv6 protocol can be transported across an MPLS backbone network.

• Chapter 10, “Any Transport over MPLS”— This chapter discusses how the MPLS network can transport Layer 2 services.

• Chapter 11, “Virtual Private LAN Service”— This chapter describes how an Ethernet LAN can be emulated across an MPLS backbone network.

• Chapter 12, “MPLS and Quality of Service”— This chapter discusses how the MPLS network can provide QoS and how the QoS information is propagated in MPLS networks.

• Chapter 13, “Troubleshooting MPLS Networks”— This chapter looks at various troubleshooting techniques and tools that you can use in MPLS networks.

• Chapter 14, “MPLS Operation and Maintenance”— This chapter focuses on MPLS Operation and Maintenance (OAM) and how it is used to detect operational failures, accounting, and performance measurement in the MPLS network.

• Chapter 15, “The Future of MPLS”— This chapter provides a brief insight into the future of MPLS and likely enhancements and developments that could be made to MPLS.

• Appendix A, “Answers to the Chapter Review Questions”— This appendix provides the answers to the questions at the end of each chapter.

About the Cisco Press Website for This Book

Cisco Press provides additional content that you can access by registering your individual book at the Ciscopress.com website. To register this book, go to http://www.ciscopress.com/bookstore/register.asp and enter the book ISBN, which is located on the back cover. You are then prompted to log in or join Ciscopress.com to continue registration. After you register this book, you see a link to this book listed on your My Registered Books page. Becoming a member and registering is free.

The following supplemental chapters and online appendix are available at this website. These chapters provide more advanced topics to support the concepts in the book.

• Chapter 4 Supplement, “Label Distribution Protocol”

• Chapter 7 Supplement, “MPLS VPN”

• Chapter 8 Supplement, “MPLS Traffic Engineering”

• Chapter 9 Supplement, “IPv6 over MPLS”

• Chapter 10 Supplement, “Any Transport over MPLS”

• Appendix B, “Static MPLS Labels”