The definitive deep-dive guide to hardware and software troubleshooting on Cisco Nexus switches

The Cisco Nexus platform and NX-OS switch operating system combine to deliver unprecedented speed, capacity, resilience, and flexibility in today's data center networks. Troubleshooting Cisco Nexus Switches and NX-OS is your single reference for quickly identifying and solving problems with these business-critical technologies.

Three expert authors draw on deep experience with large Cisco customers, emphasizing the most common issues in real-world deployments, including problems that have caused major data center outages. Their authoritative, hands-on guidance addresses both features and architecture, helping you troubleshoot both control plane forwarding and data plane/data path problems and use NX-OS APIs to automate and simplify troubleshooting. Throughout, you'll find real-world configurations, intuitive illustrations, and practical insights into key platform-specific behaviors.

This is an indispensable technical resource for all Cisco network consultants, system/support engineers, network operations professionals, and CCNP/CCIE certification candidates working in the data center domain.

· Understand the NX-OS operating system and its powerful troubleshooting tools

· Solve problems with cards, hardware drops, fabrics, and CoPP policies

· Troubleshoot network packet switching and forwarding

· Properly design, implement, and troubleshoot issues related to Virtual Port Channels (VPC and VPC+)

· Optimize routing through filtering or path manipulation

· Optimize IP/IPv6 services and FHRP protocols (including HSRP, VRRP, and Anycast HSRP)

· Troubleshoot EIGRP, OSPF, and IS-IS neighbor relationships and routing paths

· Identify and resolve issues with Nexus route maps

· Locate problems with BGP neighbor adjacencies and enhance path selection

· Troubleshoot high availability components (BFD, SSO, ISSU, and GIR)

· Understand multicast protocols and troubleshooting techniques

· Identify and solve problems with OTV

· Use NX-OS APIs to automate troubleshooting and administrative tasks

Vinit Jain, CCIE No. 22854 (R&S, SP, Security & DC), is a technical leader with the Cisco Technical Assistance Center (TAC) providing escalation support in areas of routing and data center technologies. Vinit is a speaker at various networking forums, including Cisco Live events globally on various topics. Prior to joining Cisco, Vinit worked as a CCIE trainer and a network consultant. In addition to his CCIEs, Vinit holds multiple certifications on programming and databases. Vinit graduated from Delhi University in Mathematics and earned his Master's in nformation Technology from Kuvempu University in India. Vinit can be found on Twitter as @VinuGenie.

Brad Edgeworth, CCIE No. 31574 (R&S & SP), is a systems engineer at Cisco Systems. Brad is a distinguished speaker at Cisco Live, where he has presented on various topics. Before joining Cisco, Brad worked as a network architect and consultant for various Fortune 500 companies. Brad's expertise is based on enterprise and service provider environments with an emphasis on architectural and operational simplicity. Brad holds a Bachelor of Arts degree in Computer Systems Management from St. Edward's University in Austin, Texas. Brad can be found on Twitter as @BradEdgeworth.

Richard Furr, CCIE No. 9173 (R&S & SP), is a technical leader with the Cisco Technical Assistance Center (TAC), supporting customers and TAC teams around the world. For the past 17 years, Richard has worked for the Cisco TAC and High Touch Technical Support (HTTS) organizations, supporting service provider, enterprise, and data center environments. Richard specializes in resolving complex problems found with routing protocols, MPLS, multicast, and network overlay technologies.

Foreword xxvi

Introduction xxvii

Part I Introduction to Troubleshooting Nexus Switches

Chapter 1 Introduction to Nexus Operating System (NX-OS) 1

Nexus Platforms Overview 2

Nexus 2000 Series 2

Nexus 3000 Series 3

Nexus 5000 Series 4

Nexus 6000 Series 4

Nexus 7000 Series 5

Nexus 9000 Series 6

NX-OS Architecture 8

The Kernel 9

System Manager (sysmgr) 9

Messages and Transactional Services 11

Persistent Storage Services 13

Feature Manager 14

NX-OS Line Card Microcode 17

File Systems 19

Understanding NX-OS Software Releases and Packaging 25

Software Maintenance Upgrades 27

Licensing 28

NX-OS High-Availability Infrastructure 28

Supervisor Redundancy 29

ISSU 34

NX-OS Virtualization Features 35

Virtual Device Contexts 35

Virtual Routing and Forwarding 37

Virtual Port Channel 37

Management and Operations Capabilities 39

NX-OS Advanced CLI 39

Technical Support Files 44

Accounting Log 45

Feature Event-History 46

Debug Options: Log File and Filters 47

Configuration Checkpoint and Rollback 48

Consistency Checkers 49

Feature Scheduler, EEM, and Python 50

Bash Shell 51

Summary 51

References 51

Chapter 2 NX-OS Troubleshooting Tools 53

Packet Capture: Network Sniffer 53

Encapsulated Remote SPAN 57

SPAN on Latency and Drop 60

Nexus Platform Tools 63

Ethanalyzer 63

Packet Tracer 71

NetFlow 72

NetFlow Configuration 73

NetFlow Sampling 77

sFlow 78

Network Time Protocol 81

Embedded Event Manager 83

Logging 87

Debug Logfiles 90

Accounting Log 91

Event-History 92

Summary 93

References 93

Chapter 3 Troubleshooting Nexus Platform Issues 95

Troubleshooting Hardware Issues 95

Generic Online Diagnostic Tests 98

Nexus Device Health Checks 108

Nexus Fabric Extenders 124

Virtual Device Context 130

VDC Resource Template 131

Configuring VDC 133

VDC Initialization 134

Out-of-Band and In-Band Management 137

VDC Management 137

Troubleshooting NX-OS System Components 142

Message and Transaction Services 144

Netstack and Packet Manager 148

ARP and Adjacency Manager 160

EthPM and Port-Client 175

HWRL, CoPP, and System QoS 179

MTU Settings 192

Summary 195

References 196

Part II Troubleshooting Layer 2 Forwarding

Chapter 4 Nexus Switching 197

Network Layer 2 Communication Overview 197

Virtual LANs 200

VLAN Creation 201

Access Ports 203

Trunk Ports 204

Private VLANS 207

Spanning Tree Protocol Fundamentals 218

IEEE 802.1D Spanning Tree Protocol 219

Rapid Spanning Tree Protocol 220

Multiple Spanning-Tree Protocol (MST) 236

Detecting and Remediating Forwarding Loops 241

MAC Address Notifications 242

BPDU Guard 243

BPDU Filter 244

Problems with Unidirectional Links 245

Summary 252

References 254

Chapter 5 Port-Channels, Virtual Port-Channels, and FabricPath 255

Port-Channels 255

Basic Port-Channel Configuration 259

Verifying Port-Channel Status 260

Verifying LACP Packets 262

Advanced LACP Configuration Options 265

LACP System Priority 268

Port-Channel Member Interface Consistency 271

Troubleshooting LACP Interface Establishment 272

Troubleshooting Traffic Load-Balancing 272

Virtual Port-Channel 274

vPC Fundamentals 275

vPC Con…