Implementing High Availability 255

　　Distributed VLANs on Access Switches 256

　　Local VLANs on Access Switches 256

　　Layer 3 Access to the Distribution Interconnection 257

　　Daisy Chaining Access Layer Switches 257

　　StackWise Access Switches 259

　　Too Little Redundancy 260

　　Implementing Network Monitoring 262

　　Network Management Overview 262

　　Syslog 263

　　Syslog Message Format 265

　　Configuring Syslog 267

　　SNMP 269

　　SNMP Versions 270

　　SNMP Recommendations 272

　　Configuring SNMP 272

　　IP Service Level Agreement 273

　　IP SLA Measurements 273

　　IP SLA Operations 275

　　IP SLA Source and Responder 275

　　IP SLA Operation with Responder 275

　　IP SLA Responder Timestamps 277

　　Configuring IP SLA 277

　　Implementing Redundant Supervisor Engines in Catalyst Switches 280

　　Route Processor Redundancy 281

　　Route Processor Redundancy Plus 282

　　Configuring and Verifying RPR+ Redundancy 283

　　Stateful Switchover (SSO) 284

　　Configuring and Verifying SSO 285

　　NSF with SSO 286

　　Configuring and Verifying NSF with SSO 287

　　Understanding First Hop Redundancy Protocols 288

　　Introduction to First Hop Redundancy Protocol 288

　　Proxy ARP 289

　　Static Default Gateway 290

　　Hot Standby Router Protocol (HSRP) 291

　　HSRP States 294

　　HSRP State Transition 295

　　HSRP Active Router and Spanning Tree Topology 296

　　Configuring HSRP 296

　　HSRP Priority and Preempt 297

　　HSRP Authentication 298

　　HSRP Timer Considerations and Configuration 299

　　HSRP Versions 301

　　HSRP Interface Tracking 302

　　HSRP Object Tracking 304

　　HSRP and IP SLA Tracking 305

　　Multiple HSRP Groups 306

　　HSRP Monitoring 307

　　Virtual Router Redundancy Protocol 309

　　VRRP Operation 311

　　VRRP Transition Process 312

　　Configuring VRRP 312

　　Gateway Load Balancing Protocol 315

　　GLBP Functions 316

　　GLBP Features 317

　　GLBP Operations 318

　　GLBP Interface Tracking 318

　　GLBP Configuration 322

　　GLBP with VLAN Spanning Across Access Layer Switches 322

　　Cisco IOS Server Load Balancing 323

　　Cisco IOS SLB Modes of Operation 325

　　Configuring the Server Farm in a Data Center with Real Servers 326

　　Configuring Virtual Servers 328