IPv6 Address Planning: Designing an Address Plan for the Future

by Tom Coffeen

Overview

If you’re ready to join the move to IPv6, this comprehensive guide gets you started by showing you how to create an effective IPv6 address plan. In three example-driven sections—preparation, design, and maintenance—you’ll learn principles and best practices for designing, deploying, and maintaining an address plan far beyond what’s possible with IPv4 networks.

During the course of the book, you’ll walk through the process of building a sample address plan for a fictional company. Enterprise IT network architects, engineers, and administrators will see firsthand how IPv6 provides opportunities for creating an operationally efficient plan that’s scalable, flexible, extensible, manageable, and durable.

• Explore IPv6 addressing basics, including representation, structure, and types
• Manage risks and costs by using a three-phase approach for deploying IPv6
• Dig into IPv6 subnetting methods and learn how they differ from IPv4
• Determine the appropriate size and type of the IPv6 allocation you require
• Apply current network management tools to IPv6
• Use IPv6 renumbering methods that enable greater network scale and easier integration
• Implement policies and practices to keep IPv6 addresses reachable

Product Details

ISBN-13:	9781491902769
Publisher:	O'Reilly Media, Incorporated
Publication date:	11/28/2014
Pages:	283
Product dimensions:	6.90(w) x 9.10(h) x 0.70(d)

About the Author

Tom Coffeen is currently an IPv6 evangelist at Infoblox, Inc where he focuses on helping customers deploy IPv6 and enhancing IPv6 product strategy. Prior to Infoblox, Tom led the successful deployment of IPv6 at a global service provider. He brings seventeen years of network engineering and architecture experience to his current role. Tom lives in San Francisco with his partner, Eva, and their elderly cattle dog, Wojciehowicz.

Table of Contents

Foreword xi

Preface xiii

1 Where We've Been, Where We're Going 1

Introduction 1

All the Stars in the Universe… 3

In the Beginning 6

A Dilemma of Scale 7

IPv4 Exhaustion and NAT 10

IPv6 Arrives 13

Why Not a "Flag Day" for IPv6? 14

Conclusion 16

Part I Preparation

2 What You Need to Know About IPv6 Addressing 21

Representation 21

Structure 23

Types 25

Unicast Addresses 25

Multicast Addresses 28

Anycast Addresses 29

The Unspecified Address 29

Protocol Improvements 31

Subnetting Host Bits 32

Loopback Addresses 33

Point-to-Point Link Subnets 33

Host Address Assignment 34

The Problem with NAT 35

Practical Example: Production Loopback Addresses 39

3 Planning Your IPv6 Deployment 45

Introduction 45

The IPv6 Business Case You Already Have 45

IPv6 Adoption as a Cross-Functional Initative 47

A Phased Approach to IPv6 Adoption 49

Phase 1 Preparation 49

Management Buy-in 50

Training 51

Creating an IPv6 Task Force 51

Auditing Hardware and Software for IPv6 Support 52

Verifying That Your ISP Supports IPv6 56

Obtaining an IPv6 Address Allocation 57

Phase 2 External Adoption 57

Dual-Stack Eyeballs Are Happy Eyeballs 58

Phase 3 Internal Adoption 62

Reliance on NAT 62

IPv6 Business Case Redux 53

IPv6 (In)Security 63

Internal Adoption and Operational Wisdom 64

Part II Design

4 IPv6 Subnetting 69

Introduction 59

Subnetting IPv4: A Brief Review 69

A Note on Efficiency 72

Nibble Boundaries 75

Prefix Legibility 75

Visualizing Hierarchy 77

Non-Nibble Subnetting 81

A Bit to the Left, a Bit to the Right 83

Subnets from the Right-Most Bits 84

Subnets from the Left-Most Bits 34

Subnets from the Middle Bits 85

Using Only Numeric Subnets 86

ipv6gen 87

5 IPv6 Address Planning Concepts 91

Introduction 91

IPv6 Address Planning Principles 91

Properly-Sized Initial IPv6 Allocations 92

Sparse Assignment of Subnets 93

Hierarchical Organization of Subnets 94

Uniform Subnetting and Summarization 94

Subnets in Reserve 94

Why Don't I Use My Existing IPv4 Plan in IPv6? 94

Address Plan Structure 96

What Is a Site? 98

Intra-Site Versus Inter-Site Planning 101

IPv6 Allocation Methods 105

Best-Fit Allocation 105

Sparse Allocation 108

N+1 Allocation 111

Random Allocation 113

Assigning Subnets by Location or Function 113

VLAN-Mapped IPv6 Addresses 117

Summary 119

6 Getting IPv6 Addresses 121

Introduction 121

The IP Address Supply Chain 122

So Where Will Your IPv6 Addresses Come From? 123

How Many ISPs Do You Connect To? 123

How Large Is Your Organization? 124

So Why Doesn't Everyone Just Get a PI Allocation? 124

Everything You Didn't Realize You Wanted to Know About RIR Policy 127

Measuring IPv6 Address Consumption 130

Determining Initial Allocation Size 130

Navigating the IPv6 Address Request Process 132

RIR Allocation Request 132

ISP Allocation Request 140

Summary 141

7 Creating an IPv6 Addressing Plan 143

Introduction 143

Meet Strangelove Solutions, LLC 143

Edge Network 145

Campus Network 145

Lab Network 146

Data Center Network 146

Infrastructure 146

Where to Start: Topology or Plan? 147

Mapping Topology to Plan Between Sites 147

Mapping Plan to Topology Within Sites 149

Function and Location Assignment Revisited 154

Assigning Function and Location 156

Addressing the Data Center 158

Summary 161

Part III Maintenance

8 Working with SPAM and DDI 165

Introduction 165

IP Address Management 166

IPAM as a Cornerstone of Network Management 166

Why More Than 1.8x10¹⁹ Addresses Aren't a Substitute for Proper IPAM 167

IPAM Policy 168

IPAM Features 169

Example: Using IPAM Software 174

Adding an IPv6 Prefix 175

Splitting an IPv6 Prefix 177

Creating Reverse-Mapping DNS Zones 179

DDI: IPAM with 200% More Goodness 180

Managing DHCPv6 and IPv6 DNS 181

DHCPv6 Basics 182

Configuring DHCPv6 in DDI 184

DHCPv6 Challenges 188

IPv6 DNS Considerations in DDI 190

IPv6 DNS Basics 190

Configuring IPv6 DNS in DDI 191

Summary 196

9 Managing Growth and Change 197

Introduction 197

Renumerology: IP Renumbering Made Easy…(or Somewhat Less Painful) 197

The Lifetime and State of an Autoconfigured Address 199

Preparing to Renumber 201

The Renumbering Method 202

Frequent Renumbering 204

Unplanned Growth 205

An Address in Cloud City 206

The Internet of Things 209

Characteristics of IoT Devices 212

IPv6 Address Planning for IoT Deployments 214

Three Suggestions for IoT IPv6 Address Assignments 215

Summary 215

10 Keeping Your IPv6 Addresses Reachable 217

Introduction 217

Routing with IPv6 217

Selecting Your IPv6 Routing Protocol(s) 219

Operational Continuity 219

Distance Vector and Link State Routing Protocols 219

Dual-Stack…but Not Necessarily Dual Topology 221

IS-IS for IPv6: Single-topology or Multi-topology Mode 221

OSPFv3 Address Families 222

MP-BGP 224

Routing Table Size and TCAM Space 225

RIB versus FIB 226

Mars Needs IP Address Blocks 228

Attack of the Bogons! 230

Filtering Bogons 231

Summary 235

Glossary 237

A Planning Worksheets 243

B IPv6 Prefix Maps 247

C Recommended Reading 251

Index 253