Cisco Certified DevNet Professional DEVCOR 350-901 Official Cert Guide

Jason Davis is a distinguished engineer for the DevNet program in the Developer Relations organization at Cisco. His role is technical strategy lead for the DevRel organization as he collaborates with various Cisco business unit leaders, partners, customers, and other industry influencers. Jason is focused on automation, orchestration, cloud-native technologies, and network management/operations technologies. He has a tenured career working with hundreds of customers, worldwide, in some of the largest network automation and management projects and is sought out for consulting and innovative leadership. His former experience as a U.S. Army Signal Corps officer has provided insights to defense, government, and public-sector projects, while his extensive work in professional services at Cisco has spanned commercial, large-enterprise, and service provider segments. Most of his customer engagements have been in automotive, manufacturing, large retail, large event venues, and health care. Jason has achieved Cisco Live Distinguished Speaker Hall of Fame status and is an automation/monitoring lead for the network operations center (NOC) at Cisco Live events in the U.S. and Europe. He resides in Apex, North Carolina, and enjoys IoT projects, home automation, and audio/video technologies in houses of worship. Jason and his wife, Amy, have four children whom they homeschool and cherish daily. Jason is found on social media @SNMPguy.Hazim Dahir, CCIE No. 5536, is a distinguished engineer at the Cisco office of the CTO. He is working to define and influence next-generation digital transformation architectures across multiple technologies and verticals. Hazim started his Cisco tenure in 1996 as a software engineer and subsequently moved into the services organization focusing on large-scale network designs. He's currently focusing on developing architectures utilizing security, collaboration, Edge computing, and IoT technologies addressing the future of work and hybrid cloud requirements for large enterprises. Through his passion for engineering and sustainability, Hazim is currently working on advanced software solutions for electric and autonomous vehicles with global automotive manufacturers. Hazim is a Distinguished Speaker at Cisco Live and is a frequent presenter at multiple global conferences and standards bodies. He has multiple issued and pending patents and a number of innovation and R&D publications.Stuart Clark, DevNet Expert #2022005, started his career as a hairdresser in 1990, and in 2008 he changed careers to become a network engineer. After cutting his teeth in network operations, he moved to network projects and programs. Stuart joined Cisco in 2012 as a network engineer, rebuilding one of Cisco's global networks and designing and building Cisco's IXP peering program. After many years as a network engineer, Stuart became obsessed with network automation and joined Cisco DevNet as a developer advocate for network automation. Stuart contributed to the DevNet exams and was part of one of the SME teams that created, designed, and built the Cisco Certified DevNet Expert. Stuart has presented at more than 50 external conferences and is a multi-time Cisco Live Distinguished Speaker, covering topics on network automation and methodologies. Stuart lives in Lincoln, England, with his wife, Natalie, and their son, Maddox. He plays guitar and rocks an impressive two-foot beard while drinking coffee. Stuart can be found on social media @bigevilbeard.Quinn Snyder is a developer advocate within the Developer Relations organization inside Cisco, focusing on datacenter technologies, both on-premises and cloud-native. In this role, he aligns his passion for education and learning with his enthusiasm for helping the infrastructure automation community grow and harness the powers of APIs, structured data, and programmability tooling. Prior to his work as a DA, Quinn spent 15 years in a variety of design, engineering, and implementation roles across datacenter, utility, and service provider customers for both Cisco and the partner community. Quinn is a proud graduate of Arizona State University (go Sun Devils!) and a Cisco Network Academy alumnus. He is the technical co-chair of the SkillsUSA - Arizona Internetworking contest and is involved with programmability education at the state and regional level for the Cisco Networking Academy. Quinn resides in the suburbs of Phoenix, Arizona, with his wife, Amanda, and his two kids. In his free time, you can find him behind a grill, behind a camera lens, or on the soccer field coaching his daughter's soccer teams. Quinn can be found on social media @qsnyder, usually posting a mixture of technical content and his culinary creations.

• Introduction xxviiiPart I Software Development and DesignChapter 1 Software Development Essentials 2"Do I Know This Already?" Quiz 2A Brief History of the Future 4The Evolution 5Automation, Orchestration, and DevOps 6Software Architecture and Design 9Architecture Requirements 10Functional Requirements 13Nonfunctional Requirements 13Architectural Patterns 14Software Development Lifecycle (SDLC) Approach 15Software Development Models 17Waterfall 17Agile Software Development 18Scrum 19Extreme Programming 19Kanban 19Lean 19Which Model? 20Architecture and Code Reviews 21Software Testing 22Exam Preparation Tasks 23Chapter 2 Software Quality Attributes 26"Do I Know This Already?" Quiz 26Foundation Topics 29Quality Attributes and Nonfunctional Requirements 29Brief Overview of the Most Common Quality Attributes 29Measuring Quality Attributes 35Modularity in Application Design 36Benefits of Modularity 36Modularity Coding Best Practices 37Microservices and Modular Design 40Scalability in Application Design 41Horizontal Scalability 41Vertical Scalability 42Practical Scalability in Application Design 43High Availability and Resiliency in Application Design 44Failure or Fault Detection 46Recovery: High Availability in Practice 47Prevention 50High Availability Planning and the Responsibilities of the Developer 50High Availability Deployment Models 51Exam Preparation Tasks 53Chapter 3 Architectural Considerations and Performance Management 56"Do I Know This Already?" Quiz 57Foundation Topics 59Maintainable Design and Implementation 59Maintaining a SOLID Design 60Single Responsibility Principle (SRP) 61Open-Closed Principle (OCP) 62Liskov's Substitution Principle (LSP) 63Interface Segregation Principle (ISP) 64Dependency Inversion Principle (DIP) 65Latency and Rate Limiting in Application Design and Performance 66Designing for Application Low Latency and High Performance 69Architecture Trade-offs 69Improving Performance 69Design and Implementation for Observability 73Logging 74Metrics 76Tracing 77Good Documentation Practices: An Observability Reminder 78Database Selection Criteria 79Database Requirements Gathering 80Data Volume 81Data Velocity 82Data Variety 82Exam Preparation Tasks 83Chapter 4 Version Control and Release Management with Git 86"Do I Know This Already?" Quiz 86Foundation Topics 88Version Control and Git 88Git Workflow 88Branch and Pull Workflow 89Pros 89Cons 89Sample Setup 90Sample Branch and Pull Workflow 90Fork and Pull Workflow 104Pros 105Cons 105Sample Setup 105Sample Fork and Pull Workflow 106Git Branching Strategy 121What Is a Branching Strategy? 121The Most Important Factor When Selecting a Git Branching Strategy 122Popular Git Branching Strategies 122When to Use GitHub Flow 122When to Use Git Flow 123When to Use GitLab Flow 123Recommended GitHub Settings 125Configuring the PR Merge Button 125Configuring a Branch Protection Rule to Require Code Reviews 125Exam Preparation Tasks 127Part II APIsChapter 5 Network APIs 130"Do I Know This Already?" Quiz 130Foundation Topics 132What Are APIs? 132Methods 133Objects 134Formats 134APIs vs. No API 135Web Scraping 135Jeff Bezos's API Mandate: How the AWS API-Driven Cloud Was Born 136Calling an API 138What Is API Development? 144API Architectural Styles 146Selecting an API Style 147HTTP/JSON 149REST/JSON 150Cache-Control 151REST vs. RPC 152gRPC 154OpenAPI/Swagger 155Network API Styles 157NETCONF APIs 158Exam Preparation Tasks 160Chapter 6 API Development 162"Do I Know This Already?" Quiz 163Foundation Topics 165Creating API Clients 165Code Generation Client API Libraries for IMDb 165Adding CLI Wrapper Code 174Making Calls to IMDb Using a CLI Program 174API Design Considerations 177API Authentication Models 179Flow Control (Pagination vs. Streaming) 181Error Handling, Timeouts, and Rate Limiting 184Caching 188Exam Preparation Tasks 189Part III Application Development, Deployment, and SecurityChapter 7 Application Deployment 192"Do I Know This Already?" Quiz 193Foundation Topics 194The Evolution of Application Responsibilities 194The Hybridization of Development and Operations 194The Journey to DevOps 195A Cultural Shift 196The Emergence of the Site Reliability Engineer(ing) 196SRE Responsibilities and Tenets 197SRE vs. DevOps 198Continuous Integration/Continuous Delivery (Deployment) 198Continuous Integration (CI) 199Continuous Delivery: One of the CDs 200Continuous Deployment: The Other CD 200CI/CD Pipeline Implementation 201Pipeline Components 203Build 204Test 205Release/Deliver 205Deploy 205Adding Deployment to Integration 207Deploying to Infrastructure (Terraform + Atlantis) 207Deploying Applications (Flux + Kubernetes) 213Application Deployment Methods over Time 218The 2000s: Sysadmins, Terminals, and SSH 218The 2010s: Automated Configuration Management 220The 2020s: The Clouds Never Looked So Bright 224Managed Kubernetes (e.g., GKE) 224Containers on Serverless Clouds (e.g., AWS ECS on Fargate) 227Serverless Functions (e.g., AWS Lambda) 234Software Practices for Operability: The 12-Factor App 238Factor 1: Codebase 239Factor 2: Dependencies 239Factor 3: Config 239Factor 4: Backing Services 240Factor 5: Build, Release, Run 240Factor 6: Processes 240Factor 7: Port Binding 241Factor 8: Concurrency 241Factor 9: Disposability 241Factor 10: Dev/Prod Parity 241Factor 11: Logs 242Factor 12: Admin Processes 242Summary 243Exam Preparation Tasks 243Chapter 8 Security in Application Design 246"Do I Know This Already?" Quiz 247Foundation Topics 248Protecting Privacy 250Personally Identifiable Information 250Data States 250Laws, Regulations, and Standards for Protecting Privacy 251Storing IT Secrets 252Public Key Infrastructure (PKI) 254Certificate Revocation 256Hierarchical Multiple CA Infrastructure 257TLS, PKI, and Web Applications Security 257Browser Security Issues 261Securing Web and Mobile Applications 262Injection Attacks 263Cross-Site Scripting 264OAuth Authorization Framework 266How Does OAuth Work? 266OAuth 2.0 Two-Legged Authorization 268OAuth 2.0 Three-Legged Authorization 269Additional OAuth Authorization Code Grant Types 271OAuth 2.0 Client Credentials 271Resource Owner Password Credential Flow 272OAuth 2.0 Implicit Flow 275OAuth 2.0 Authorization Code Flow 276OAuth 2.0 PKCE Flow 278Refresh Token Flow 280OAuth 2.0 Device Code Flow 281Exam Preparation Tasks 283Part IV Infrastructure and AutomationChapter 9 Infrastructure 286"Do I Know This Already?" Quiz 286Foundation Topics 288Network Management 288Methods of Network Provisioning 290CLI/Console 291SNMP 294File Transfer Methods 297Element Management Systems 297Embedded Management 299Zero-Touch Provisioning (ZTP) 300Atomic or SDN-Like/Controller-Based Networking 303Advanced Concepts - Intent-Based Networking 305Summary 307Exam Preparation Tasks 307Chapter 10 Automation 310"Do I Know This Already?" Quiz 311Foundation Topics 313Challenges Being Addressed 313Differences of Equipment and Functionality 314Proximity of Management Tools and Support Staff 316Speed of Service Provisioning 317Accuracy of Service Provisioning 319Scale 323Doing More with Less 329Software-Defined Networking (SDN) 329What Is SDN and Network Programmability? 329Approach 330Nontraditional Entities 331Industry Impact 331New Methods 331Normalization 332Enabling Operations 332Enabling Career Options 332Use Cases and Problems Solved with SDN 332Overview of Network Controllers 334The Cisco Solutions 335Application Programming Interfaces (APIs) 335REST APIs 336API Methods 337API Authentication 337API Pagination 337Payload Data Formats JSON XML 338XML 338JSON 340Cross-Domain, Technology-Agnostic Orchestration (CDTAO) 342Impact to IT Service Management and Security 343Exam Preparation Tasks 344Chapter 11 NETCONF and RESTCONF 346"Do I Know This Already?" Quiz 346Foundation Topics 348Catalyst for NETCONF 348Content 349Operations 350Messages 350Transport 351Atomic and Model-Driven Configuration Management 351How to Implement NETCONF 354Enabling NETCONF on IOS XE 355Enabling NETCONF on IOS XR 356Enabling NETCONF on NX-OS 357Basic Manual Use of NETCONF 358YANG Models 365The Evolution with RESTCONF 371The RESTCONF Protocol Stack 372RESTCONF Operations 372RESTCONF and Authentication 373RESTCONF URIs 373Performing a RESTCONF GET Operation with cURL 375Performing RESTCONF GET Operations with the Postman Utility 377Management Solutions Using NETCONF and RESTCONF 382Exam Preparation Tasks 383Chapter 12 Model-Driven Telemetry 386"Do I Know This Already?" Quiz 387Foundation Topics 389Transformation of Inventory, Status, Performance, and Fault Monitoring 389Scaling with the Push Model 391How to Implement Model-Driven Telemetry 393Dial-In and Dial-Out Mode 395Encoding (Serialization) 395Protocols 396Configuring MDT in IOS-XR 398Configuring Dial-Out Mode 398Step 1: Create a Destination Group 398Step 2: Create a Sensor Group 400Step 3: Create a Subscription 400Step 4: Verify the Dial-Out Configuration 401Configuring Dial-In Mode 402Step 1: Enable gRPC 402Step 2: Create a Sensor Group 404Step 3: Create a Subscription 405Step 4: Validate the Configuration 405Picking Sensor Paths and Metrics 407Researching Public Documentation 407Extracting Model Support from the Device - NETCONF Manually 408Extracting Model Support from the Device - Python and NETCONF 410Digging into the YANG Models 414Installing Docker to the Linux VM 414Installing the YANG Suite Docker Image to the Linux VM 415Practical Application of Streaming Telemetry 423Using Telegraph, InfluxDB, and Grafana 426Installing InfluxDB 426Installing Telegraf 428Beyond MDT: Event-Driven Telemetry 434Other Considerations: Disk Usage 440Frequency of Telemetry Push 441Exam Preparation Tasks 441Chapter 13 Open-Source Solutions 444"Do I Know This Already?" Quiz 445Foundation Topics 447Infrastructure-as-Code (IaC) Concepts 447Imperative and Declarative Models 448Provisioning or Configuration Management 449Differences Between Agent and Agentless Solutions 450Agent-Based Solutions: Puppet and Chef 450Agentless Solutions: Ansible and Terraform 474Installing Ansible from the Package Manager 474Installing the Latest Ansible from a Virtual Python Environment with pip 476Configuring Ansible Inventory 481Creating a Project-Level Inventory File 482Creating an Ansible Playbook to Obtain show Command Results 483Filtering, Templating, and Jinja2 487Using Ansible to Modify Device Configurations 488Terraform Overview 493Installing Terraform 494Using Terraform 496Cisco Solutions Enabled for IaC 501Exam Preparation Tasks 502Chapter 14 Software Configuration Management 508"Do I Know This Already?" Quiz 508Foundation Topics 510Software Configuration Management (SCM) 510SCM Definitions and Standards 510Why Do You Need SCM? 511Which SCM Process Is Best for You? 512Ansible 512Terraform 515Terraform or Ansible: A High-Level Comparison 518Business and Technical Requirements 519Architectural Decisions 519Technical Debt 520Exam Preparation Tasks 521Chapter 15 Hosting an Application on a Network Device 524"Do I Know This Already?" Quiz 524Foundation Topics 527Benefits of Edge Computing 527Virtualization Technologies 527Type-1 Hypervisors 528Type-2 Hypervisors 528Linux Containers (LXC) 529Docker Containers 530Application Container Ideas 532Platforms Supporting Application Containers 533How to Implement Application Containers 534Validating Prerequisites 534Enabling Application Hosting Framework 536Using Cisco DNA Center for App Hosting 538Using Cisco IOx Local Manager for App Hosting 547Using the Command-Line Interface for App Hosting 553Interacting with App Hosted iPerf3 556Best Practices for Managing Application Containers 563Exam Preparation Tasks 565Part V PlatformsChapter 16 Cisco Platforms 568"Do I Know This Already?" Quiz 568Foundation Topics 571Webex 571Enabling the Webex REST API/SDK Access 572Webex API Documentation 573API Examples 575SDK Examples 577Firepower 582Enabling API/SDK Access to Firepower 582Firepower API Documentation 583Meraki 592Enabling API/SDK Access to Meraki 592Meraki API Documentation 593Meraki SDK Documentation 594Meraki Authorization 596Intersight 601Enabling API Access to Intersight 601Intersight API Documentation 603Intersight SDK Documentation 605Intersight Authorization 606UCS Manager 611Enabling API Access to UCS Manager 611UCS Manager API Documentation 611Python SDK Documentation 617PowerShell SDK Documentation 622Additional UCS Manager Programmability Resources 628DNA Center 628Enabling API/SDK Access to DNA Center 630DNA Center API Documentation 631DNA Center SDK Documentation 635SDK Authorization 637AppDynamics 639Exam Preparation Tasks 646Chapter 17 Final Preparation 648Getting Ready 648Tools for Final Preparation 649Pearson Cert Practice Test Engine and Questions on the Website 649Accessing the Pearson Test Prep Software Online 649Accessing the Pearson Test Prep Software Offline 649Customizing Your Exams 650Updating Your Exams 651Premium Edition 651Chapter-Ending Review Tools 652Suggested Plan for Final Review/Study 652Summary 652Appendix A Answers to the "Do I Know This Already?" Questions 654Appendix B Cisco DevNet Professional DEVCOR 350-901 Exam Updates 672Glossary 675Online ElementsAppendix C Memory TablesAppendix D Memory Tables Answer KeyAppendix E Dashboard BasicsGlossary9780137370443 TOC 5/23/2022