Implementing Cisco IP Routing (ROUTE) Foundation Learning Guide

Diane Teare is a professional in the networking, training, project management, and e-learning fields. She has more than 25 years of experience in designing, implementing, and troubleshooting network hardware and software, and has been involved in teaching, course design, and project management. She has extensive knowledge of network design and routing technologies, and is an instructor with one of the largest authorized Cisco Learning Partners. She was the director of e-learning for the same company, where she was responsible for planning and supporting all the company’s e-learning offerings in Canada, including Cisco courses. Diane has a bachelor’s degree in applied science in electrical engineering and a master’s degree in applied science in management science. She currently holds her Cisco Certified Network Professional (CCNP), Cisco Certified Design Professional (CCDP), and Project Management Professional (PMP) certifications. She co-authored the Cisco Press titles Designing Cisco Network Service Architectures (ARCH), Second Edition; Campus Network Design Fundamentals; the three editions of Authorized Self-Study Guide Building Scalable Cisco Internetworks (BSCI); and Building Scalable Cisco Networks. Diane edited the two editions of the Authorized Self-Study Guide Designing for Cisco Internetwork Solutions (DESGN) and Designing Cisco Networks.

    Introduction xxvii

Chapter 1 Routing Services 1

    Complex Enterprise Network Frameworks, Architectures, and Models 1

        Traffic Conditions in a Converged Network 1

        Cisco IIN and SONA Framework 3

        Cisco IIN 3

        Cisco SONA Framework 4

        Cisco Network Models 6

        Cisco Enterprise Architecture 6

        Cisco Hierarchical Network Model 8

        Cisco Enterprise Composite Network Model 9

    Creating, Documenting, and Executing an Implementation Plan 13

        Approaches to Creating an Implementation Plan 14

        Creating an Implementation Plan 15

        Implementation Plan Documentation 17

        Implementation Plan Example 18

        Example Network Scenario 18

        Example Network Requirements 18

        Example Network Implementation Plan 19

    Reviewing IP Routing Principles 21

        IP Routing Overview 22

        Principles of Static Routing 22

        Principles of Dynamic Routing 26

        Principles of On-Demand Routing 28

        Characteristics of Routing Protocols 30

        Distance Vector, Link-State, and Advanced Distance Vector

        Routing Protocols 30

        Classful Routing Protocol Concepts 31

        Classless Routing Protocol Concepts 35

        RIPv2 and EIGRP Automatic Network-Boundary Summarization 35

        RIP 38

        Characteristics of RIPv1 38

        Characteristics of RIPv2 38

        RIP Configuration Commands 39

        Populating the Routing Table 41

        Administrative Distance 41

        Routing Protocol Metrics 43

        Criteria for Inserting Routes into the IP Routing Table 45

        Floating Static Routes 45

        IP Routing Protocol Comparisons 46

        Routing and Routing Protocols Within the Enterprise Composite

        Network Model 48

    Summary 49

    Review Questions 51

Chapter 2 Configuring the Enhanced Interior Gateway Routing Protocol 57

    Understanding EIGRP Terminology and Operation 58

        EIGRP Capabilities and Attributes 58

        EIGRP Terminology 61

        EIGRP Operation 63

        Populating EIGRP Tables 63

        EIGRP Packets 65

        EIGRP Neighbors 67

        Initial Route Discovery 69

        DUAL 71

        Advertised Distance and Feasible Distance 71

        Successor and Feasible Successor 72

        DUAL Example 75

        EIGRP Metric Calculation 80

    Planning EIGRP Routing Implementations 83

    Configuring and Verifying EIGRP 84

        Planning and Configuring Basic EIGRP 85

        Planning for Basic EIGRP 85

        Basic EIGRP Configuration 86

        Basic Configuration Example 88

        Another Basic EIGRP Configuration Example 89

        Verifying EIGRP Operation 90

        Verifying EIGRP Neighbors 93

        Verifying EIGRP Routes 94

        Verifying EIGRP Operations 96

        Using the passive-interface Command with EIGRP 104

        Propagating an EIGRP Default Route 107

        EIGRP Route Summarization 109

        Configuring Manual Route Summarization 110

        Verifying Manual Route Summarization 112

    Configuring and Verifying EIGRP in an Enterprise WAN 113

        EIGRP over Frame Relay and on a Physical Interface 113

        Frame Relay Overview 113

        EIGRP on a Physical Frame Relay Interface with

        Dynamic Mapping 114

        EIGRP on a Frame Relay Physical Interface with Static Mapping 116

        EIGRP over Frame Relay Multipoint Subinterfaces 118

        Frame Relay Multipoint Subinterfaces 118

        EIGRP over Multipoint Subinterfaces 119

        EIGRP Unicast Neighbors 121

        EIGRP over Frame Relay Point-to-Point Subinterfaces 123

        Frame Relay Point-to-Point Subinterfaces 123

        EIGRP on Frame Relay Point-to-Point Subinterfaces 123

        EIGRP over MPLS 125

        MPLS 125

        MPLS Operation 126

        Service Provider Offerings 127

        Layer 2 and Layer 3 MPLS VPN Solutions 128

        Layer 3 MPLS VPNs 128

        Layer 2 MPLS VPNs 132

        EIGRP Load Balancing 134

        EIGRP Equal-Cost Load Balancing 134

        EIGRP Unequal-Cost Load Balancing 136

        EIGRP Bandwidth Use Across WAN Links 139

        EIGRP Link Utilization 139

        Examples of EIGRP on WANs 140

    Configuring and Verifying EIGRP Authentication 144

        Router Authentication 144

        Simple Authentication Versus MD5 Authentication 144

        MD5 Authentication for EIGRP 146

        Planning for EIGRP Authentication 147

        Configuring EIGRP MD5 Authentication 147

        MD5 Authentication Configuration Example 148

        Verifying MD5 Authentication for EIGRP 152

        EIGRP MD5 Authentication Verification 153

        Troubleshooting MD5 Authentication 154

    Optimizing EIGRP Implementations 156

        EIGRP Scalability in Large Networks 156

        EIGRP Queries and Stuck-in-Active 158

        Stuck-in-Active Connections in EIGRP 158

        Preventing SIA Connections 160

        EIGRP Query Range 161

        Limiting the EIGRP Query Range 164

        Graceful Shutdown 173

    Summary 174

    References 179

    Review Questions 179

Chapter 3 Configuring the Open Shortest Path First Protocol 185

    Understanding OSPF Terminology and Operation 186

        Link-State Routing Protocols 186

        OSPF Area Structure 188

        OSPF Areas 191

        Area Terminology 192

        OSPF Adjacencies 193

        OSPF Metric Calculation 195

        Link-State Data Structures 196

    OSPF Packets 197

        Establishing OSPF Neighbor Adjacencies: Hello 199

        Exchange Process and OSPF Neighbor Adjacency States 201

        OSPF Neighbor States 204

        Maintaining Routing Information 205

        OSPF Link-State Sequence Numbers 207

        Verifying Packet Flow 208

        Configuring and Verifying Basic OSPF Routing 209

        Planning and Configuring OSPF 209

        Planning OSPF Routing Implementations 209

    Configuring Basic OSPF 211

        Single-Area OSPF Configuration Example 212

        Multiarea OSPF Configuration Example 213

        OSPF Router ID 214

        Loopback Interfaces 215

        OSPF router-id Command 215

        Verifying the OSPF Router ID 216

        Verifying OSPF Operations 217

        The show ip ospf interface Command 218

        The show ip ospf neighbor Command 219

        The show ip route ospf Command 221

        The show ip protocols Command 221

        The debug ip ospf events Command 222

    Understanding OSPF Network Types 222

        Types of OSPF Networks 222

        Electing a DR and BDR and Setting Priority 223

        Adjacency Behavior for a Point-to-Point Link 224

        Adjacency Behavior for a Broadcast Network 224

        Adjacency Behavior over a Layer 2 MPLS VPN 225

        Adjacency Behavior over a Layer 3 MPLS VPN 226

        Adjacency Behavior for an NBMA Network 227

        DR Election in an NBMA Topology 228

        OSPF over Frame Relay Topology Options 228

        OSPF over NBMA Topology Modes of Operation 229

        Selecting the OSPF Network Type for NBMA Networks 229

        OSPF Configuration in Cisco Broadcast Mode 231

        OSPF Nonbroadcast Mode Configuration 231

        OSPF Configuration in Point-to-Multipoint Mode 233

        OSPF Configuration in Cisco Point-to-Multipoint

        Nonbroadcast Mode 236

        Using Subinterfaces in OSPF over Frame Relay Configuration 236

        OSPF Configuration in Cisco Point-to-Point Mode 239

        OSPF over NBMA Modes of Operation Summary 240

        Displaying OSPF Adjacency Activity 241

    Understanding OSPF LSAs 244

        LSA Type 1: Router LSA 246

        LSA Type 2: Network LSA 247

        LSA Type 3: Summary LSA 247

        LSA Type 4: Summary LSA 248

        LSA Type 5: External LSA 249

        Example OSPF LSAs in a Network 250

    Interpreting the OSPF LSDB and Routing Table 250

        OSPF LSDB 250

        OSPF Routing Table and Types of Routes 254

        Calculating the Costs of E1 and E2 Routes 255

        Configuring OSPF LSDB Overload Protection 256

    Configuring and Verifying Advanced OSPF Features 258

        Using the passive-interface Command with OSPF 258

        Propagating an OSPF Default Route 260

        Configuring OSPF Route Summarization 263

        Configuring Inter-area OSPF Route Summarization on an ABR 265

        Interarea Route Summarization Configuration Example

        on an ABR 266

        Configuring External OSPF Route Summarization on an ASBR 267

        External Route Summarization Configuration Example

        on an ASBR 268

        OSPF Virtual Links 269

        Configuring OSPF Virtual Links 270

        Verifying OSPF Virtual Link Operation 272

        OSPF LSDB for Virtual Links 275

        Changing the Cost Metric 278

        Configuring OSPF Special Area Types 279

        Configuring Stub Areas 281

        Configuring Totally Stubby Areas 284

        Interpreting Routing Tables in Different Types of OSPF Areas 286

        Configuring NSSAs 289

        Configuring Totally Stubby NSSAs 294

        Example OSPF Area Types in a Network 295

        Verifying All Area Types 296

    Configuring and Verifying OSPF Authentication 297

        Planning for OSPF Authentication 297

        Configuring, Verifying, and Troubleshooting OSPF Simple Password

        Authentication 297

        Configuring OSPF Simple Password Authentication 297

        Simple Password Authentication Example 299

        Verifying Simple Password Authentication 300

        Troubleshooting Simple Password Authentication 301

        Configuring OSPF Simple Password Authentication for Virtual Links 304

        Configuring, Verifying, and Troubleshooting MD5 Authentication 305

        Configuring OSPF MD5 Authentication 305

        MD5 Authentication Example 307

        Verifying MD5 Authentication 308

        Troubleshooting MD5 Authentication 309

    Summary 311

    References 314

    Review Questions 315

Chapter 4 Manipulating Routing Updates 325

    Assessing Network Routing Performance Issues 326

    Routing Protocol Performance Issues 326

        Routing Protocol Performance Solutions 327

    Using Multiple IP Routing Protocols on a Network 329

        Understanding a Network with Complex Routing 329

        Understanding Route Redistribution 330

        Redistribution Overview 330

        Redistributed Routes 332

        Redistribution Implementation Considerations 334

        Selecting the Best Route in a Redistribution Environment 335

        Redistribution Techniques 338

        One-Point Redistribution 339

        Multipoint Redistribution 340

        Preventing Routing Loops in a Redistribution Environment 342

    Implementing Route Redistribution 344

        Configuring Route Redistribution 344

        Redistributing into RIP 346

        Redistributing into OSPF 347

        Redistributing into EIGRP 350

        The default-metric Command 352

        The passive-interface Command 353

        Route Redistribution Example 355

        Using Administrative Distance to Influence

        the Route-Selection Process 358

        Selecting Routes with Administrative Distance 358

        Modifying Administrative Distance 361

        Redistribution Using Administrative Distance Example 363

        Verifying Redistribution Operation 369

    Controlling Routing Update Traffic 370

        Static and Default Routes 371

        Using Route Maps 373

        Route Map Applications 373

        Understanding Route Maps 374

        Configuring Route Maps to Control Routing Updates 376

        Configuring Route Maps for Policy Based Routing 377

        Configuring Route Redistribution Using Route Maps 379

        Using Route Maps with Redistribution 380

        Using Route Maps to Avoid Route Feedback 381

        Using Route Maps with Tags 382

        Using Route Maps with Redistribution and Tags 382

        Using Distribute Lists 384

        Configuring Distribute Lists to Control Routing Updates 386

        Controlling Redistribution with Distribute Lists 389

        Using Prefix Lists 390

        Prefix List Characteristics 390

        Filtering with Prefix Lists 391

        Configuring Prefix Lists 391

        Verifying Prefix Lists 397

        Using Multiple Methods to Control Routing Updates 398

        Comprehensive Example of Controlling Routing Updates 398

    Summary 412

    References 415

    Review Questions 416

Chapter 5 Implementing Path Control 419

    Understanding Path Control 419

        Assessing Path Control Network Performance 419

        Path Control Tools 421

    Implementing Path Control Using Offset Lists 424

        Using Offset Lists to Control Path Selection 424

        Configuring Path Control Using Offset Lists 424

        Verifying Path Control Using Offset Lists 426

    Implementing Path Control Using Cisco IOS IP SLAs 426

        Using Cisco IOS IP SLAs to Control Path Selection 427

        Cisco IOS IP SLAs Operation 429

        Cisco IOS IP SLAs Sources and Responders 429

        Cisco IOS IP SLAs Operations 430

        Cisco IOS IP SLAs Operation with Responders 430

        Cisco IOS IP SLAs with Responder Time Stamps 432

        Configuring Path Control Using IOS IP SLAs 432

        Configuring Cisco IOS IP SLAs Operations 433

        Configuring Cisco IOS IP SLAs Tracking Objects 436

        Configuring the Action Associated with the Tracking Object 436

        Verifying Path Control Using IOS IP SLAs 437

        Examples of Path Control Using Cisco IOS IP SLAs 438

        Tracking Reachability to Two ISPs 438

        Tracking DNS Server Reachability in the Two ISPs 440

    Implementing Path Control Using Policy-Based Routing 446

        Using PBR to Control Path Selection 447

        Configuring PBR 448

        PBR match Commands 448

        PBR set Commands 449

        Configuring PBR on an Interface 452

        Verifying PBR 454

        PBR Examples 454

        Using PBR When Connecting Two ISPs 454

        Using PBR Based on Source Address 457

        Alternative Solution IP SLAs Configuration Example Using PBR 459

    Advanced Path Control Tools 460

        Cisco IOS Optimized Edge Routing 460

        Virtualization 461

        Cisco Wide Area Application Services 462

    Summary 463

    References 467

    Review Questions 467

Chapter 6 Implementing a Border Gateway Protocol Solution for ISP Connectivity 471

    BGP Terminology, Concepts, and Operation 471

        Autonomous Systems 471

        BGP Use Between Autonomous Systems 474

        Comparison with Other Scalable Routing Protocols 475

        Connecting Enterprise Networks to an ISP 477

        Public IP Address Space 478

        Connection Link Type and Routing 478

        Connection Redundancy 482

        Using BGP in an Enterprise Network 485

        BGP Multihoming Options 486

        Multihoming with Default Routes from All Providers 487

        Multihoming with Default Routes and Partial Table from All Providers 488

        Multihoming with Full Routes from All Providers 491

        BGP Path Vector Characteristics 492

        When to Use BGP 494

        When Not to Use BGP 495

        BGP Characteristics 495

        BGP Neighbor Relationships 497

        External BGP Neighbors 497

        Internal BGP Neighbors 498

        IBGP on All Routers in a Transit Path 500

        IBGP in a Transit Autonomous System 500

        IBGP in a Nontransit Autonomous System 501

        BGP Partial-Mesh and Full-Mesh Examples 501

        TCP and Full Mesh 502

        Routing Issues If BGP Not on in All Routers in a Transit Path 503

        BGP Synchronization 504

        BGP Tables 506

        BGP Message Types 508

        Open and Keepalive Messages 508

        Update Messages 509

        Notification Messages 509

        BGP Attributes 510

        Well-Known Attributes 511

        Optional Attributes 511

        Defined BGP Attributes 512

        The AS-Path Attribute 513

        The Next-Hop Attribute 514

        The Origin Attribute 517

        The Local Preference Attribute 518

        The Community Attribute 519

        The MED Attribute 519

        The Weight Attribute (Cisco Only) 520

        The Route-Selection Decision Process 521

        BGP Route-Selection Process 522

        The Path-Selection Decision Process with a Multihomed

        Connection 525

    Configuring BGP 526

        Planning BGP Implementations 527

        Peer Groups 527

        Entering BGP Configuration Mode 529

        Defining BGP Neighbors and Activating BGP Sessions 529

        Shutting Down a BGP Neighbor 531

        Defining the Source IP Address 531

        EBGP Multihop 534

        Changing the Next-Hop Attribute 536

        Defining the Networks That BGP Advertises 538

        BGP Neighbor Authentication 540

        Configuring BGP Synchronization 542

        Resetting BGP Sessions 542

        Hard Reset of BGP Sessions 543

        Soft Reset of BGP Sessions Outbound 544

        Soft Reset of BGP Sessions Inbound 544

        BGP Configuration Examples 546

        Basic BGP Examples 546

        Peer Group Example 547

        IBGP and EBGP Examples 549

    Verifying and Troubleshooting BGP 552

        show ip bgp Command Output Example 552

        show ip bgp rib-failure Command Output Example 554

        show ip bgp summary Command Output Example 554

        debug ip bgp updates Command Output Example 556

        Understanding and Troubleshooting BGP Neighbor States 557

        Idle State Troubleshooting 558

        Active State Troubleshooting 558

        Established State 559

    Basic BGP Path Manipulation Using Route Maps 559

        BGP Path Manipulation 560

        Changing the Weight 562

        Changing the Weight for All Updates from a Neighbor 562

        Changing the Weight Using Route Maps 562

        Setting Local Preference 564

        Changing Local Preference for All Routes 564

        Local Preference Example 565

        Changing Local Preference Using Route Maps 567

        Setting the AS-Path 568

        Setting the MED 570

        Changing the MED for All Routes 571

        Changing the MED Using Route Maps 572

        Implementing BGP in an Enterprise Network 575

    Filtering BGP Routing Updates 576

        BGP Filtering Using Prefix Lists 578

        Planning BGP Filtering Using Prefix Lists 578

        BGP Filtering Using Prefix Lists Example 578

        BGP Filtering Using Route Maps 580

        Planning BGP Filtering Using Route Maps 580

        BGP Filtering with Route Maps Example 580

    Summary 582

    References 587

    Review Questions 587

Chapter 7 Implementing Routing Facilities for Branch Offices and Mobile Workers 591

    Planning the Branch Office Implementation 591

        Branch Office Design 591

        Upgrade Scenario 595

        Implementation Plan 596

        Deploying Broadband Connectivity 597

        Satellite Broadband Information 598

        Cable Background Information 601

        DSL Background Information 603

        PPPoA 606

        Configuring Static Routing 609

        Routing to the Internet 611

        Floating Static Route 615

        Verifying Branch Services 618

        Configuring NAT 619

        Verifying NAT 623

        Verifying Other Services 629

        Verifying and Tuning IPsec VPNs 631

        IPsec Technologies 632

        Encapsulation Process 633

        IPsec Site-to-Site VPN Configuration 635

        ISAKMP Policy 636

        IPsec Details 637

        VPN Tunnel Information 637

        VPN ACL 638

        Apply the Crypto Map 638

        Verifying an IPsec VPN 639

        Impact on Routing 647

        Configuring GRE Tunnels 647

        Generic Routing Encapsulation 649

        Configuring GRE 650

        Example of GRE Configuration 652

    Planning for Mobile Worker Implementations 661

        Connecting a Mobile Worker 661

        Components for Mobile Workers 662

        Business-Ready Mobile Worker and VPN Options 663

    Routing Traffic to the Mobile Worker 664

        VPN Headend Configuration 665

        Allowing IPsec Traffic 666

        Defining Address Pools 670

        Providing Routing Services for VPN Subnets 672

        Tuning NAT for VPN Traffic Flows 675

        Verifying IPsec VPN Configuration 677

        Reviewing Alternatives for Mobile Worker Connectivity 683

    Summary 685

    References 688

    Review Questions 688

Chapter 8 Implementing IPv6 in an Enterprise Network 691

    Introducing IPv6 691

        IPv4 Issues 692

        Features of IPv6 693

        IPv6 Packet Header 695

        Extension Headers 696

        MTU Discovery 698

    IPv6 Addressing 698

        IPv6 Addressing in an Enterprise Network 698

        IPv6 Address Representation 700

        Interface Identifiers in IPv6 Addresses 701

        IPv6 Address Types 704

        IPv6 Global Unicast Addresses 705

        IPv6 Link-Local Unicast Addresses 707

        IPv6 Site-Local Unicast Addresses: Deprecated 708

        IPv6 Multicast Addresses 708

        Solicited-Node Multicast Addresses 710

        IPv6 Anycast Addresses 711

        Comparing IPv6 Addresses with IPv4 Addresses 712

    Configuring and Verifying IPv6 Unicast Addresses 716

        IPv6 Unicast Address Configuration and Verification Commands 717

        Static IPv6 Address Assignment 719

        Static Global Aggregatable Address Assignment 719

        Assigning Multiple Global Aggregatable Addresses 721

        IPv6 Unnumbered Interfaces 723

        Static Link-Local Address Assignment 723

        Stateless Autoconfiguration of IPv6 Addresses 724

        Unicast Connectivity on Different Connection Types 733

        Unicast Connectivity on Broadcast Multiaccess Links 733

        Unicast Connectivity on Point-to-Point Links 738

        Unicast Connectivity on Point-to-Multipoint Links 742

    Routing IPv6 Traffic 746

        IPv6 Routing Protocols 747

        Static Routing 747

        Static Route Configuration and Verification Commands 747

        Static Route Configuration and Verification Example 750

        RIPng 751

        RIPng Configuration and Verification Commands 752

        RIPng Configuration and Verification Example 752

        OSPFv3 759

        Similarities Between OSPFv2 and OSPFv3 760

        Differences Between OSPFv2 and OSPFv3 761

        OSPFv3 Configuration and Verification Commands 763

        OSPFv3 Configuration and Verification Examples 767

        EIGRP for IPv6 773

        EIGRP for IPv6 Configuration and Verification Commands 773

        EIGRP for IPv6 Configuration and Verification Example 774

        MBGP 782

        MBGP Configuration and Verification Commands 783

        MBGP Configuration and Verification Example 784

        IPv6 Policy-Based Routing 785

        IPv6 PBR Configuration and Verification Commands 785

        IPv6 PBR Configuration and Verification Example 788

        IPv6 Redistribution 791

        RIPng Redistribution 791

        RIPng and OSPFv3 Redistribution 799

        RIPng, OSPFv3, and MBGP Redistribution 814

    Transitioning IPv4 to IPv6 824

        Dual Stack 826

        Tunneling 828

        Translation 829

    Tunneling IPv6 Traffic 830

        Manual IPv6 Tunnels 830

        Manual IPv6 Tunnel Configuration and Verification Commands 831

        Manual IPv6 Tunnel Configuration and Verification Example 832

        GRE IPv6 Tunnels 838

        GRE IPv6 Tunnel Configuration and Verification Commands 839

        GRE IPv6 Tunnel Configuration and Verification Examples 839

        6to4 Tunnels 846

        6to4 Tunnel Configuration and Verification Commands 848

        6to4 Tunnel Configuration and Verification Example 848

        IPv4-Compatible IPv6 Tunnels 854

        IPv4-Compatible IPv6 Tunnel Configuration and Verification Commands 854

        IPv4-Compatible IPv6 Tunnel Configuration and Verification Example 854

        ISATAP Tunnels 857

        ISATAP Tunnel Configuration and Verification Commands 859

        ISATAP Tunnel Configuration and Verification Example 859

    Translation Using NAT-PT 864

        Static NAT-PT for IPv6 865

        Static NAT-PT Operation 865

        Static NAT-PT Configuration and Verification Commands 866

        Static NAT-PT Configuration and Verification Example 867

        Dynamic NAT-PT for IPv6 871

        Dynamic NAT-PT Configuration and Verification Commands 872

        Dynamic NAT-PT Configuration and Verification Examples 873

    Summary 885

    References 897

    Review Questions 897

Appendix A Answers to Review Questions 901

Online Supplemental Material:

    Appendix B IPv4 Supplement

    Appendix C BGP Supplement

    Acronyms and Abbreviations

TOC, 9781587058820, 5/25/10