Introduction xxv Chapter 1 Basic Network and Routing Concepts 1 Differentiating Routing Protocols 2 Enterprise Network Infrastructure 2 Role of Dynamic Routing Protocols 3 Choosing a of Dynamic Routing Protocols 5 IGP versus EGP 5 Types of Routing Protocols 7 Convergence 8 Route Summarization 9 Route Protocol Scalability 10 Understanding Network Technologies 10 Traffic Types 11 IPv6 Address Types 13 ICMPv6 Neighbor Discovery 14 Network Types 15 NBMA Networks 16 Routing Over the Internet 18 Connecting Remote Locations with Headquarters 18 Principles of Static Routing 19 Configuring an IPv4 Static Route 20 Configuring a Static Default Route 22 Basic PPP Overview 23 PPP Authentication Overview 23 PPPoE 26 Basic Frame Relay Overview 28 VPN Connectivity Overview 31 MPLS-based VPNs 31 Tunneling VPNs 32 Hybrid VPNs 32 Routing Across MPLS VPNs 32 Routing Over GRE Tunnel 34 Dynamic Multipoint Virtual Private Network 35 Multipoint GRE 36 NHRP 37 IPsec 39 Routing and TCP/IP Operations 40 MSS, Fragmentation, and PMTUD 40 IPv4 Fragmentation and PMTUD 41 Bandwidth Delay Product 41 TCP Starvation 42 Latency 42 ICMP Redirect 42 Implementing RIPng 43 RIP Overview 43 RIPv2 Overview 45 Configuring RIPng 47 Basic RIPng Configuration 47 Propagating a Default Route 50 Investigating the RIPng Database 53 Summary 55 Review Questions 56 Chapter 2 EIGRP Implementation 59 Establishing EIGRP Neighbor Relationships 60 EIGRP Features 60 EIGRP Features 62 EIGRP Operation Overview 63 Configuring and Verifying Basic EIGRP for IPv4 64 Manipulating EIGRP Timers 73 EIGRP Neighbor Relationship over Frame Relay 74 Establishing EIGRP over Layer 3 MPLS VPN 74 Establishing EIGRP over Layer 2 MPLS VPN 75 Building the EIGRP Topology Table 76 Building and Examining the EIGRP Topology Table 77 Choosing the Best Path 80 Exchange of Routing Knowledge in EIGRP 88 EIGRP Metric 88 EIGRP Metric Calculation 89 EIGRP Wide Metrics 90 EIGRP Metric Calculation Example 90 EIGRP Metric Calculation Example 91 EIGRP Path Calculation Example 92 Optimizing EIGRP Behavior 94 EIGRP Queries 95 EIGRP Stub Routers 96 Configuring EIGRP Stub Routing 97 EIGRP Stub Options 100 Stuck in Active 108 Reducing Query Scope by Using Summary Routes 109 Configuring EIGRP Summarization 110 Determining the Summary Route 116 Obtaining Default Route 120 Load Balancing with EIGRP 123 Configuring EIGRP Load Balancing 123 EIGRP Load Balancing 124 EIGRP Load Balancing Across Unequal-Metric Paths 126 Configuring EIGRP for IPv6 128 Overview of EIGRP for IPv6 128 Configuring and Verifying EIGRP for IPv6 129 EIGRP for IPv6 Configuration 130 Determining the IPv6 Summary Route 134 Named EIGRP Configuration 136 Introduction to Named EIGRP Configuration 136 Configuring Named EIGRP 137 Address Families 139 EIGRP for IPv4 Address Family 139 EIGRP for IPv6 Address Family 142 Named EIGRP Configuration Modes 148 Classic Versus Named EIGRP Configuration 150 Summary 151 Review Questions 152 Chapter 3 OSPF Implementation 155 Establishing OSPF Neighbor Relationships 155 OSPF Features 156 OSPF Operation Overview 157 Hierarchical Structure of OSPF 158 Design Restrictions of OSPF 160 OSPF Message Types 160 Basic OSPF Configuration 161 Optimizing OSPF Adjacency Behavior 170 Using OSPF Priority in the DR/BDR Election 174 OSPF Behavior in NBMA Hub-and-Spoke Topology 175 The Importance of MTU 177 Manipulating OSPF Timers 179 OSPF Neighbor Relationship over Point-to-Point Links 182 OSPF Neighbor Relationship over Layer 3 MPLS VPN 182 OSPF Neighbor Relationship over Layer 2 MPLS VPN 184 OSPF Neighbor States 184 OSPF Network Types 186 Configuring Passive Interfaces 187 Building the Link-State Database 187 OSPF LSA Types 188 Examining the OSPF Link-State Database 189 OSPF Link-State Database 190 OSPF Type 2 Network LSA 196 OSPF Type 3 Summary LSA 197 OSPF Type 4 ASBR Summary LSA 199 OSPF Type 5 External LSA 201 Periodic OSPF Database Changes 203 Exchanging and Synchronizing LSDBs 204 Synchronizing the LSDB on Multiaccess Networks 206 Running the SPF Algorithm 207 Configuring OSPF Path Selection 208 OSPF Path Selection 208 OSPF Best Path Calculation 210 Default OSPF Costs 211 Calculating the Cost of Intra-Area Routes 214 Calculating the Cost of Interarea Routes 214 Selecting Between Intra-Area and Interarea Routes 215 Optimizing OSPF Behavior 215 OSPF Route Summarization 216 Benefits of Route Summarization 217 Configuring OSPF Route Summarization 218 Summarization on ABRs 223 Summarization on ASBRs 224 OSPF Virtual Links 225 Configuring OSPF Virtual Links 227 Configuring OSPF Stub Areas 229 OSPF Stub Areas 230 OSPF Totally Stubby Areas 234 Cost of the Default Route in a Stub Area 236 The default-information originate Command 237 Other Stubby Area Types 238 OSPFv3 239 Configuring OSPFv3 240 Implementing OSPFv3 241 OSPFv3 for IPv4 and IPv6 246 Configuring Advanced OSPFv3 260 OSPFv3 Caveats 261 Summary 262 Review Questions 263 Chapter 4 Manipulating Routing Updates 267 Using Multiple IP Routing Protocols on a Network 267 Why Run Multiple Routing Protocols? 269 Running Multiple Routing Protocols 269 Administrative Distance 269 Multiple Routing Protocols Solutions 270 Implementing Route Redistribution 270 Defining Route Redistribution 270 Planning to Redistribute Routes 271 Redistributing Routes 271 Seed Metrics 272 Default Seed Metrics 273 Configuring and Verifying Basic Redistribution in IPv4 and IPv6 275 Redistributing OSPFv2 Routes into the EIGRP Routing Domain 276 Redistributing OSPFv3 Routes into the EIGRP for IPv6 Routing Domain 279 Redistributing EIGRP Routes into the OSPFv2 Routing Domain 281 Redistributing EIGRP for IPv6 Routes into the OSPFv3 Routing Domain 285 Types of Redistribution Techniques 287 One-Point Redistribution 287 Multipoint Redistribution 288 Redistribution Problems 289 Preventing Routing Loops in a Redistribution Environment 291 Verifying Redistribution Operation 292 Controlling Routing Update Traffic 292 Why Filter Routes? 292 Route Filtering Methods 293 Using Distribute Lists 294 Configuring Distribute Lists 294 Distribute List and ACL Example 295 Using Prefix Lists 297 Prefix List Characteristics 297 Configuring Prefix Lists 298 Distribute List and Prefix List Example 299 Prefix List Examples 300 Verifying Prefix Lists 301 Manipulating Redistribution Using ACLs, Prefix Lists, and Distribute Lists 302 Using Route Maps 305 Understanding Route Maps 305 Route Map Applications 305 Configuring Route Maps 306 Route Map Match and Set Statements 308 Configuring Route Redistribution Using Route Maps 310 Using Route Maps with Redistribution 310 Manipulating Redistribution Using Route Maps 311 Mutual Redistribution without Route Filtering 312 Mutual Redistribution with Route Maps 313 Change Administrative Distance to Enable Optimal Routing 315 Manipulating Redistribution Using Route Tagging 318 Caveats of Redistribution 319 Summary 320 References 323 Review Questions 323 Chapter 5 Path Control Implementation 327 Using Cisco Express Forwarding Switching 327 Control and Data Plane 328 Cisco Switching Mechanisms 328 Process and Fast Switching 332 Cisco Express Forwarding 333 Analyzing Cisco Express Forwarding 335 Verify the Content of the CEF Tables 335 Enable and Disable CEF by Interface and Globally 341 Understanding Path Control 343 The Need for Path Control 343 Implementing Path Control Using Policy-Based Routing 344 PBR Features 344 Steps for Configuring PBR 345 Configuring PBR 346 Verifying PBR 348 Configuring PBR Example 348 Implementing Path Control Using Cisco IOS IP SLAs 354 PBR and IP SLA 354 IP SLA Features 354 Steps for Configuring IP SLAs 356 Verifying Path Control Using IOS IP SLAs 360 Configuring IP SLA Example 361 Configuring PBR and IP SLA Example 364 Summary 369 References 370 Review Questions 370 Chapter 6 Enterprise Internet Connectivity 373 Planning Enterprise Internet Connectivity 374 Connecting Enterprise Networks to an ISP 374 Enterprise Connectivity Requirements 374 ISP Redundancy 375 Public IP Address Assignment 376 The Internet Assigned Numbers Authority 376 Regional Internet Registries 377 Public IP Address Space 377 Autonomous System Numbers 378 Establishing Single-Homed IPv4 Internet Connectivity 381 Configuring a Provider-Assigned IPv4 Address 381 D.