Understanding and Troubleshooting Cisco Catalyst 9800 Series Wireless Controllers

Simone Arena is a principal technical marketing engineer (TME) within the Cisco Enterprise Networking & Cloud group and is primarily focused on enterprise network architecture and on all things related to wireless and mobility. Simone is based in Italy and is a Cisco veteran, having joined Cisco in 1999. Throughout the years, Simone has covered multiple roles at Cisco, starting as a software engineer working with Catalyst switching platforms, to consulting system engineer in the field, to TME within different teams (Enterprise Solution Engineering, Wireless Business Unit, Enterprise Networking and Cloud, and now Networking Experiences Group). Today Simone is the lead TME architect for Catalyst Wireless, and his time is split between helping customers and partners design the best solution that fits their needs and engineering and product management, trying to evolve and improve the products and solutions. Simone is a Distinguished Speaker at Cisco Live and has spoken at Cisco Live events all over the world for several years. Besides wireless and networking, Simone has two passions: his family, with his two daughters Viola and Anita; and Fiorentina, the best soccer team in the world...no question. In his spare time, Simone enjoys listening to music, especially through his new tube amplifier (simply awesome!). Francisco Sedano Crippa, CCIE No. 14859, joined Cisco in 2006. After some years at TAC supporting voice solutions and as a system engineer working with service providers, he moved to the development side, where he worked on routing, datacenter and, during the past 10 years, as a technical leader on the Wireless Controller development team, focused in serviceability, location services, programmability, and cloud. He's a Cisco Live speaker and is passionate about DevOps and automation, and he is now working on architecting next-generation cloud-based lab services. When not working, he spends his time building a full-size Boeing 737 simulator in his basement and enjoying his other passion: his daughter, Scarlett, and son, Marco, and his wife, Isabel. Nicolas Darchis, CCIE Wireless No. 25344, joined the Wireless and AAA Cisco TAC team in Belgium in 2007, where his main focus was troubleshooting wireless networks, wireless management tools, and security products. Since 2016, Nicolas has been working as a technical leader for wireless at the same technical assistance center in Brussels; he has shifted a big part of his focus to improving product serviceability of new and upcoming products, as well as new software releases. He is also a major contributor to online documentation of Cisco wireless products and has participated in many of the wireless "Ask the Expert" sessions run by the Cisco support community. Nicolas has been a CCIE Wireless No. 25344 since 2009 and, more recently, he has achieved CWNE No. 208. Sudha Katgeri, CCIE No. 45857, is a technical leader in services for Enterprise Wireless and has been with Cisco since 2006. Besides supporting customer escalations, Sudha collaborates with Customer Experience (CX), Enterprise Networking (ENB) Escalation, Engineering, and Product Management to improve product quality and serviceability in the next-generation Catalyst wireless stack. Sudha has a CCIE in Wireless (#45857) and is an author and contributor to Wireless TAC Innovation Tools like Wireless Config Converter, CLI Analyzer, and several documents on cisco.com.

Introduction xxvii
Chapter 1 Cisco C9800 Series 1
Why Cisco C9800? 2
The Role of the Wireless Controller in a Cloud Era 7
Managing the Cisco C9800 10
Cisco Next-Generation Wireless Stack 22
Summary 23
References 23
Chapter 2 Hardware and Software Architecture of the C9800 25
General CAPWAP Split MAC Architecture 25
The Controller Control Plane Architecture Elasticity 27
Wireless Client State Machine 31
One Dataplane to Rule Them All (or Three at the Maximum) 35
Hardware Overview 38
Summary 42
Chapter 3 C9800 Configuration Model 43
C9800 New Configuration Model 43
Cisco C9800 Series Profile and Tag Considerations 48
Summary 64
References 64
Chapter 4 C9800 Deployment and Installation 65
C9800 Deployment Models 65
Setting Up Your First Catalyst Wireless Network 79
Summary 87
References 87
Chapter 5 Security 89
Network Security Fundamentals 89
Wireless Security Fundamentals 116
Securing the Air 128
Securing Your Access Points 148
Securing Your Wireless Controller 151
Encrypted Traffic Analytics 154
Cisco Umbrella 155
Cisco Secure Development Lifecycle (CSDL) 157
Summary 157
References 157
Chapter 6 Mobility and Client Roaming 159
802.11 Roaming 160
Types of Client Roaming 181
C9800 to AireOS Inter-Release Controller Mobility (IRCM) 191
Summary 192
References 193
Chapter 7 RF Deployment and Guidelines 195
Radio Resources Management (RRM) Concepts and Components 195
Challenging RF Environments 199
Radio Resources Management (RRM) 203
DCA 211
RF Profiles 215
Spectrum Intelligence and CleanAir 219
Advanced RF Features 224
Airtime Fairness (ATF) 228
Dynamic Frequency Selection (DFS) 232
Flexible Radio Assignment (FRA) 235
Wireless Intrusion Prevention System (WIPS) and Rogue Detection 238
Summary 246
References 246
Chapter 8 Multicast and Multicast Domain Name System (mDNS) 247
Wireless Multicast 250
Media Stream Feature 263
mDNS 272
Summary 283
References 283
Chapter 9 Quality of Service (QoS) 285
Wi-Fi Quality of Service (QoS) 286
Wi-Fi (802.11) QoS Fundamentals 287
Implementing Wireless QoS on the C9800 300
Designing and Deploying Catalyst C9800 QoS 304
Best Practices 320
Summary 322
References 322
Chapter 10 C9800 High Availability 323
SSO Redundancy 324
HA Teardown 349
SSO Deployment: Impact on Features 350
N+1 Redundancy 352
N+1 vs. SSO High Availability 357
HA in EWC-AP Deployment 358
HA in EWC-SW Deployment 359
Summary 359
References 360
Chapter 11 Cisco DNA Spaces Integration and IoT 361
Value-Added Wireless Services 361
Connected Mobile Experiences (CMX) 372
Cisco DNA Spaces 372
Specific Service Examples 379
Summary 392
References 392
Chapter 12 Network Programmability 393
What Is Network Programmability? 393
Why Is Network Programmability Needed? 393
Is Network Programmability a New Concept? 396
Orchestration of the Entire Network 396
Configuration Repeatability 396
Idempotency 397
Imperative vs. Declarative Models 397
Infrastructure as Code (IaC) 400
Network Programmability in the C9800 401
Data Models 402
YANG Data Models 403
Encoding Formats 406
Protocols 408
Tools to Examine YANG Models 412
How to Examine Data Using NETCONF and YANG Suite 419
How to Examine Data Using RESTCONF and POSTMAN 421
Python and Network Programmability 429
Summary 436
References 436
Chapter 13 Model-Driven Telemetry 437
What Is Model-Driven Telemetry? 437
How to Enable Model-Driven Telemetry 438
Operational Data and KPIs 441
Polling vs. Subscribing 447
Telemetry Streams 448
How to Identify Subtrees in YANG Models 449
Dial-out vs. Dial-in 450
Tools 460
Summary 467
References 467
Chapter 14 Cisco DNA Center/Assurance Integration 469
Introduction 469
Managing the C9800 with Cisco DNA Center 472
Summary 492
References 492
Chapter 15 Backing Up, Restoring, and Upgrading Your C9800 493
Saving and Restoring the Configuration for Disaster Recovery 493
Running IOS-XE in Install or Bundle Mode 500
Upgrading (and Downgrading) the Controller Safely 501
Summary 506
References 506
Chapter 16 Troubleshooting 507
Control Plane Tracing 509
Embedded Packet Capture (EPC) 525
Packet Tracer 531
Troubleshooting Dashboard 536
Other On-the-Box Tools on the C9800 GUI 540
Offline Tools for the C9800 545
Health and KPI Monitoring 548
Summary 577
References 578
Appendix A Setting Up a Development Environment 579


9780137492329, TOC, 5/27/2022