Today, networks must evolve and scale faster than ever. You can't manage everything by hand anymore: You need to automate relentlessly. YANG, along with the NETCONF, RESTCONF, or gRPC/gNMI protocols, is the most practical solution, but most implementers have had to learn by trial and error. Now, Network Programmability with YANG gives you complete and reliable guidance for unlocking the full power of network automation using model-driven APIs and protocols. Authored by three YANG pioneers, this plain-spoken book guides you through successfully applying software practices based on YANG data models. The authors focus on the network operations layer, emphasizing model-driven APIs, and underlying transports. Whether you're a network operator, DevOps engineer, software developer, orchestration engineer, NMS/OSS architect, service engineer, or manager, this guide can help you dramatically improve value, agility, and manageability throughout your network.

Discover the value of implementing YANG and Data Model-Driven Management in your network
Explore the layers and components of a complete working solution
Build a business case where value increases as your solution grows
Drill down into transport protocols: NETCONF, RESTCONF, and gNMI/gRPC
See how telemetry can establish a valuable automated feedback loop
Find data models you can build on, and evaluate models with similar functionality
Understand models, metadata, and tools from several viewpoints: architect, operator, module author, and application developer
Walk through a complete automation journey: business case, service model, service implementation, device integration, and operation
Leverage the authors' experience to design successful YANG models and avoid pitfalls

Autorentext

Benoît Claise, CCIE No. 2686, is a Cisco Fellow, working as an architect for embedded management. Areas of passion and expertise include Internet traffic monitoring, accounting, performance, fault, and configuration management. Benoît's area of focus these days is network automation with YANG as the data modeling language, NETCONF/RESTCONF, and telemetry as a feedback loop to solve intent-based networking.

Benoît was IETF Operations and Management Area (OPS) co-director from 2012 to 2018, a period during which much of the data model-driven management protocols, encoding, and data models were specified. He blogs on these topics on his web site http://www.claise.be/ and spends time on the yangcatalog.org developments. Benoît is a contributor to the IETF, with 35 RFCs in the area of NetFlow, IPFIX (IP Flow Information eXport), PSAMP (Packet Sampling), IPPM (IP Performance Metrics), YANG, MIB module, energy management, and network management in general. Benoît is the co-author of the Cisco Press book Network Management: Accounting and Performance Strategies.

As a Cisco Customer Experience Engineer, Joe Clarke, CCIE No. 5384, has contributed to the development and adoption of many of Cisco's network management and automation products and technologies. He helps to support, enhance, and promote the embedded automation and programmability features, such as the Embedded Event Manager, Tcl, Python, NETCONF/RESTCONF, and YANG.

Joe evangelizes these programmability and automation skills in order to build the next generation of network engineers. He is a Cisco Certified Internetworking Expert and certified Cisco Network Programmability Engineer. Joe has authored numerous technical documents on Cisco network management, automation, and programmability products and technologies, as well as a chapter as co-author of Network-Embedded Management and Applications: Understanding Programmable Networking Infrastructure. He also served as one of the technical editors for the Cisco Press books Tcl Scripting for Cisco IOS and Programming and Automating Cisco Networks: A Guide to Network Programmability and Automation in the Data Center, Campus, and WAN. He is an alumnus of the University of Miami and holds a Bachelor of Science degree in computer science.

Outside of Cisco, Joe is a member of the FreeBSD project and the co-chair of the Ops Area Working Group at the IETF. Joe is a certified commercial pilot for single-engine airplanes with an instrument rating. He lives with his beautiful wife in the RTP area of North Carolina.

Jan Lindblad soldered together his first computer at age 12, wrote his first compiler at 16, and reached the million lines of code mark by 30. In 2006, when NETCONF was first published by IETF, Jan was at the then newly founded start-up company Tail-f Systems. Tail-f built the first commercial implementation of NETCONF and was a driving force behind the introduction of YANG.

Jan is an IETF YANG Doctor and has also authored and reviewed many YANG modules in other organizations. Jan has trained several hundred people on the theory and practice of NETCONF and YANG. At the yearly NETCONF/YANG interop event organized by EANTC in Berlin, Germany, Jan plays a central role.

Outside Cisco, Jan is an avid climate activist and environmentalist. He lives outside Stockholm, Sweden, and commutes to work by bike every day.

Inhalt

Introduction xxii 1 The Network Management World Must Change: Why Should You Care? 2 Introduction 2 The Industry Has Changed: What Are the Trends? 6 Existing Network Management Practices and Related Limitations 24 Data Modeling Is Key for Automation 39 Interview with the Experts 48 Summary 52 References in This Chapter 53 Endnotes 53 2 Data Model-Driven Management 56 The Beginning: A New Set of Requirements 56 Network Management Is Dead, Long Live Network Management 59 YANG: The Data Modeling Language 61 The Management Architecture 69 Data Model-Driven Management Components 70 The Encoding (Protocol Binding and Serialization) 74 The Server Architecture: Datastore 77 The Protocols 78 The Programming Language 85 Telemetry 86 The Bigger Picture: Using NETCONF to Manage a Network 86 Interview with the Experts 91 Summary 93 References in This Chapter 93 Endnotes 94 3 YANG Explained 96 Introduction 96 Describe Your World of Data 96 Describing Possible Events 113 Separating Configuration from Operational Data 117 Constraints Keep Things Meaningful 122 Augmenting, Extending, and Possibly Deviating 142 Network Management Datastore Architecture (NMDA) 149 Interview with the Expert 154 Summary 156 References in This Chapter 157 4 NETCONF, RESTCONF, and gNMI Explained 158 Introduction 158 NETCONF 158 RESTCONF 190 OpenConfig and gNMI 214 Interview with the Expert 225 Summary 227 References in This Chapter 227 5 Telemetry Explained 230 Introduction 230 Data Model-Driven Telemetry 230 Moving Away from SNMP to Telemetry 232 Telemetry Use Cases 235 Telemetry Components 236 Telemetry Standard Mechanisms 242 Interview with the Experts 249 Summary 252 References in This Chapter 253 Endnotes 253 6 YANG Data Modeling Developments in the Industry 256 Introduction 256 The Beginning: The IETF 256 Embracing YANG Throughout the Industry 263 The OpenConfig YANG Model 268 Industry Coordination Is Required 270 Interoperability Testing 272 Implementing More Than One YANG Model for a Specific Functionality 274 Interview with the Expert 275 Summary 278 References in This Chapter 279 Endnotes 279 7 Automation Is as Good as the Data Models, Their Related Metadata, and the Tools: For the Network Architect and Operator 282 Introduction 282 Getting to Know the Structure of a YANG Module 283 Finding the Right Modules Using the YANG Catalog 287 Interacting with Devices 299 Interview with the Experts 331 Summary 335 Endnotes 335 8 Automation Is as Good as the Data Models, Their Related Metadata, and the Tools: For the Module Author 336 Introduction 336 Designing Modules 336 Understanding Your Module's Impact 349 Interview with the Expert 350 Summary 352 Endnotes 352 9 Automation Is as Good as the Data Models, Their Related Metadata, and…