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 Configuration 278 vPC Verification 280 Advanced vPC Features 288 FabricPath 294 FabricPath Terminologies and Components 296 FabricPath Packet Flow 297 FabricPath Configuration 300 FabricPath Verification and Troubleshooting 303 FabricPath Devices 310 Emulated Switch and vPC+ 310 vPC+ Configuration 311 vPC+ Verification and Troubleshooting 314 Summary 320 References 320 Part III Troubleshooting Layer 3 Routing Chapter 6 Troubleshooting IP and IPv6 Services 321 IP SLA 321 ICMP Echo Probe 322 UDP Echo Probe 324 UDP Jitter Probe 325 TCP Connect Probe 328 Object Tracking 329 Object Tracking for the Interface 330 Object Tracking for Route State 330 Object Tracking for Track-List State 332 Using Track Objects with Static Routes 334 IPv4 Services 335 DHCP Relay 335 DHCP Snooping 341 Dynamic ARP Inspection 345 IP Source Guard 349 Unicast RPF 351 IPv6 Services 352 Neighbor Discovery 352 IPv6 Address Assignment 357 IPv6 First-Hop Security 362 First-Hop Redundancy Protocol 370 HSRP 370