Introduction
Intent-Based Networking (IBN) is the next revolution in networking that Cisco, Juniper, Gartner, and others are conveying. Cisco explains the concept with the Network Intuitive communication and solutions such as Cisco DNA Center, Software Defined Access, and Cisco SD-WAN. But IBN is much more than just a combination of those technologies and solutions. It is also a concept on how a modern network infrastructure should be designed, managed, and operated, leveraging Cisco Digital Network Architecture as the foundation.
And although the concept of IBN is accepted by the industry as the next generation of network infrastructures, many IT specialists and organizations face the challenge of how to design and transform network infrastructures and network operation teams into IBN, specifically for existing environments. This challenge is mostly seen with questions like “Yes, I do understand about IBN but how do I get started?”; “Now that I installed Cisco DNA Center, what can I do with it?”; or “How can IBN help me in providing services faster to my internal users?”
This book is written as a compendium to that challenge and its related questions, specifically focusing on campus enterprise networks. This book provides a detailed explanation of IBN, specifically related to campus networks. With that background information, this book documents a unique four-phase approach to answer the question of how an organization can get started on the transformation (or journey as some call it) to IBN for existing campus networks.
As IBN requires changes in both technologies (and how they are applied) and organizations (how networks are managed), this book also provides tips on how change can be realized throughout an organization. This book should be of help and support for anybody who wants to transform their network into an Intent-Based Network.
A large part of my career as an engineer and consultant has been focused on enabling change and making change happen. The change always involved technology in one way or the other, primarily with use cases where technology would solve today’s or tomorrow’s problems, or sometimes the technology would open up new innovative ideas and concepts. As an external specialist, my role was always to help and support the organization with the change of work.
Intent-Based Networking will bring very interesting times of change to the networking industry in general. The network, specifically the campus, will play an important role in the future of any organization. The rate of change is increasing too, which I see in my day-to-day work as well. The ability to deploy intents in this manner is for me only the first step. What would be the next step when you can do this? The opportunities are really unlimited.
I have used my personal experiences and observations throughout this book together with the concepts of Cisco DNA and IBN to support you on your journey to the next generation of networks.
I do hope that reading this book provides you with enough information and background on why and how to transform an existing campus and network operations team to the concept of Intent-Based Networking.
This book also has two appendixes that are used to provide you with conceptual background information on the technologies named throughout this book as well as reference configurations for the underlay of an Intent-Based Network.
Who Should Read This Book?
This book is written for network consultants, network architects (designers), senior network engineers, and IT managers who have any questions related to IBN and how existing campus networks can be transformed to IBN. A background in networking is helpful when reading this book, but a deep technical understanding is not required as each technology is explained at a conceptual level in an appendix.
How This Book Is Organized
This book covers a diverse set of topics related to the successful transformation of an existing network to IBN and is divided into three logical parts that are best read sequentially:
Part I, “Overview of Intent-Based Networking,” provides you with background information related to campus networks and the concept of Intent-Based Networking (IBN). This part contains a logical buildup of information, starting from common classic campus network deployments, why change is required through architecture frameworks, to the concept of IBN. If you are already familiar with the specific topic of a chapter, it is possible to skip that chapter. Part I includes the following chapters:
Chapter 1, “Classic Campus Network Deployments”: This chapter provides you with an overview of campus network deployments found in many organizations today at a conceptual level. The chapter does not provide many details on how technologies are configured and used within a campus network but focuses on the conceptual designs and choices for a campus network with the advantages and disadvantages of each choice. The chapter covers concepts such as a hierarchical campus network, a collapsed-core model, different wireless deployment models, and alternatives for typical networking technologies found in the campus network such as the Spanning Tree Protocol (STP).
Chapter 2, “Why Change Current Networks? A Need for Change”: This chapter provides a summary of external trends, drivers (or forces), that require the current campus network design and operation to be changed to cope with these drivers. You will learn about external trends such as wireless/mobility, (Net)DevOps, complexity, cloud, and digitization.
Chapter 3, “Enterprise Architecture”: This chapter describes the concept of enterprise architecture, why that is beneficial to enterprises in general and specific to a network design within the enterprise. You will learn that a network design (or architecture) is part of a larger technology architecture and an architecture for the enterprise or organization as a whole. This chapter uses the TOGAF® standard for enterprise architectures both as an introduction to enterprise architecture as well as an example for the relationship between network infrastructures and enterprise architecture.
Chapter 4, “Cisco Digital Network Architecture”: This chapter provides you with a detailed explanation of Cisco Digital Network Architecture (DNA) that Cisco introduced in May 2016. Cisco DNA is an architecture that is intended to be the foundation for both modern state-of-the-art network infrastructures as well as the concept of Intent-Based Networking. You will learn the different requirements Cisco DNA has, the building blocks of its architecture, and the different design principles.
Chapter 5, “Intent-Based Networking”: In this chapter you will learn the concept of Intent-Based Networking (IBN) via the explanation of what Intent means, how that can be applied to a network infrastructure, and how it relates to Cisco Digital Network Architecture. You will learn how IBN can help the network operations team cope with the changes described in Chapter 2 and be able to remain in control of the network. Chapter 5 also introduces two technical concepts, Software Defined Access and Classic VLANs, that can be used to deploy an Intent-Based Network. Intent-Based Network (or Intent-Enabled Network) is used throughout this book as a network that is configured based on the concept of Intent-Based Networking (IBN)—that is, IBN describes the concept, and Intent-Based Network is an implementation of that concept.
Chapter 6, “Tools for Intent”: This chapter provides a short overview of the tools that are available to enable Intent-Based Networking within the campus network. In this chapter you will learn about important concepts within IBN, such as automation and assurance, and which tools can fulfill those requirements for the concept of IBN.
Part II, “Transforming to an Intent-Based Network,” describes a four-phased approach that supports you in a successful transformation to Intent-Based Networking, including tips, tricks, and problems you might face during the transformation. It is best to read this part completely and not skip a chapter as they are built on one another.
Chapter 7, “Phase One: Identifying Challenges”: This chapter describes the first phase of the transformation and is all about identifying the requirements (I used the word challenges on purpose, as that is more positive and challenges can be solved) within a campus network and getting the proper support and commitment. You will learn that IBN is a concept that not only involves (new) technologies and sets specific hardware requirements but also sets requirements and expectations on the organization. You will learn which challenges are to be identified on the required hardware and software as well as challenges related to the organization and its processes. The chapter ends with an action plan that contains details on how to approach the transformation to IBN.
Chapter 8, “Phase Two: Prepare for Intent”: This chapter describes phase two of the transformation. Phase two is used to prepare the campus network and the organization for the transformation. It starts with solving all the challenges identified in the previous phase. After these challenges are solved, the remaining steps of the phase focus on preparing the network (and network operations team) for a successful transformation to IBN. You will learn about the standardization of the campus network, the introduction of automation and assurance to the network operations team, and why these steps are important for IBN. These steps also include tips on why and how to execute them. The last section of this chapter contains information about risks that you might encounter during this phase, including some suggestions on how to cope with them.
Chapter 9, “Phase Three: Design, Deploy, and Extend”: This chapter provides all information required to actually transform the campus network to an Intent-Based Network. You will learn two technology concepts (Software Defined Access and classic VLAN) that can be used to deploy your campus network with their pros and cons. You will be executing sequential steps to gradually implement IBN on the campus network. As with the previous phases, a special section on risks for this phase allows you to identify and prepare for potential problems.
Chapter 10, “Phase Four: Enable Intent”: This chapter describes the last phase of the transformation; now that the campus network is transformed to IBN, it is time to fully take advantage of the possibilities created. The chapter involves a strategy on how you can introduce IBN to the rest of the organization, including a special methodology to allow the campus network to deliver services to the business on demand.
Part III, “Organizational Aspects,” is quite a different part compared to the first two. Whereas the first two are primarily focused on background information and hands-on for the transformation, this part provides information on the impact that IBN has on the organization. This part’s chapters can be read individually and are as follows:
Chapter 11, “Architecture Frameworks”: This chapter provides a quick recap of architecture frameworks and provides an insight to how IBN will impact and change the traditional enterprise architecture frameworks.
Chapter 12, “Enabling the Digital Business”: This chapter provides a more detailed description of the concept of digitalization and digital business. It describes how Intent-Based Networking fits within (and enables) the digital business and what impact this will have on an organizational level.
Chapter 13, “IT Operations”: This chapter describes the relationship between IBN and common IT operations. It provides an introduction to common IT operation models such as ITIL, DevOps, and Lean. It also describes what impact and change IBN will have on these IT operation models.
Chapter 14, “Tips to Make Your IBN Journey a Success”: The transformation to IBN involves quite some change, including technical, organizational, and individual. This chapter provides background information and tips on how change can be achieved at both an individual and an organizational level. It covers information on human change and associated fears, and it provides tips you can use to make the change happen. It also contains some final tips that can be used to make the transformation to IBN last.
Part IV, “Appendixes” This book also has appendixes that provide you with conceptual background information on the technologies named throughout this book as well as reference configurations for the underlay of an Intent-Based Network:
Appendix A, “Campus Network Technologies”: This appendix provides a conceptual overview of the different technologies used in this book that are commonly found on a campus network. This appendix does not provide a detailed technical explanation of the technologies but rather a more conceptual summary of the technology and how it is applied. This appendix is a recommended read for less-technical readers to provide a more common understanding of the technologies;
Appendix B, “Sample Configurations”: This appendix provides a set of sample configurations that can be used on the campus network to implement IBN; this appendix is rather technical as it contains specific configuration elements. It is provided as a head start to Intent-Based Networking for network architects and engineers.