Implementing Cisco IP Routing (ROUTE) Foundation Learning Guide

Diane Teare, P.Eng, CCNP, CCDP, CCSI, PMP, 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. Diane is a Cisco Certified Systems Instructor (CCSI), and holds her Cisco Certified Network Professional (CCNP), Cisco Certified Design Professional (CCDP), and Project Management Professional (PMP) certifications. She is an instructor, and the Course Director for the CCNA and CCNP Routing and Switching curriculum, 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 authored or co-authored the following Cisco Press titles: the first edition of this book; the second edition of Designing Cisco Network Service Architectures (ARCH); 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 first two editions of the Authorized Self-Study Guide Designing for Cisco Internetwork Solutions (DESGN), and Designing Cisco Networks.Bob Vachon, is a professor at Cambrian College in Sudbury, Ontario, Canada, where he teaches Cisco networking infrastructure courses. He has more than 30 years of work and teaching experience in the computer networking and information technology field. Since 2001, Bob has collaborated as team lead, lead author, and subject matter expert on various CCNA, CCNA-S, and CCNP projects for Cisco and the Cisco Networking Academy. He also was a contributing author for the Routing Protocols Companion Guide, Connecting Networks Companion Guide, and authored the CCNA Security (640-554) Portable Command Guide. In his downtime, Bob enjoys playing the guitar, playing pool, and either working in his gardens or white-water canoe tripping.Rick Graziani teaches computer science and computer networking courses at Cabrillo College in Aptos, California. Rick has worked and taught in the computer networking and information technology field for almost 30 years. Before teaching, Rick worked in IT for various companies, including Santa Cruz Operation, Tandem Computers, and Lockheed Missiles and Space Corporation. He holds a Master of Arts degree in computer science and systems theory from California State University Monterey Bay. Rick also works for the Cisco Networking Academy Curriculum Engineering team and has written other books for Cisco Press, including IPv6 Fundamentals. When Rick is not working, he is most likely surfing. Rick is an avid surfer who enjoys surfing at his favorite Santa Cruz breaks.

• Introduction xxvChapter 1 Basic Network and Routing Concepts 1Differentiating Routing Protocols 2Enterprise Network Infrastructure 2Role of Dynamic Routing Protocols 3Choosing a of Dynamic Routing Protocols 5IGP versus EGP 5Types of Routing Protocols 7Convergence 8Route Summarization 9Route Protocol Scalability 10Understanding Network Technologies 10Traffic Types 11IPv6 Address Types 13ICMPv6 Neighbor Discovery 14Network Types 15NBMA Networks 16Routing Over the Internet 18Connecting Remote Locations with Headquarters 18Principles of Static Routing 19Configuring an IPv4 Static Route 20Configuring a Static Default Route 22Basic PPP Overview 23PPP Authentication Overview 23PPPoE 26Basic Frame Relay Overview 28VPN Connectivity Overview 31MPLS-based VPNs 31Tunneling VPNs 32Hybrid VPNs 32Routing Across MPLS VPNs 32Routing Over GRE Tunnel 34Dynamic Multipoint Virtual Private Network 35Multipoint GRE 36NHRP 37IPsec 39Routing and TCP/IP Operations 40MSS, Fragmentation, and PMTUD 40IPv4 Fragmentation and PMTUD 41Bandwidth Delay Product 41TCP Starvation 42Latency 42ICMP Redirect 42Implementing RIPng 43RIP Overview 43RIPv2 Overview 45Configuring RIPng 47Basic RIPng Configuration 47Propagating a Default Route 50Investigating the RIPng Database 53Summary 55Review Questions 56Chapter 2 EIGRP Implementation 59Establishing EIGRP Neighbor Relationships 60EIGRP Features 60EIGRP Features 62EIGRP Operation Overview 63Configuring and Verifying Basic EIGRP for IPv4 64Manipulating EIGRP Timers 73EIGRP Neighbor Relationship over Frame Relay 74Establishing EIGRP over Layer 3 MPLS VPN 74Establishing EIGRP over Layer 2 MPLS VPN 75Building the EIGRP Topology Table 76Building and Examining the EIGRP Topology Table 77Choosing the Best Path 80Exchange of Routing Knowledge in EIGRP 88EIGRP Metric 88EIGRP Metric Calculation 89EIGRP Wide Metrics 90EIGRP Metric Calculation Example 90EIGRP Metric Calculation Example 91EIGRP Path Calculation Example 92Optimizing EIGRP Behavior 94EIGRP Queries 95EIGRP Stub Routers 96Configuring EIGRP Stub Routing 97EIGRP Stub Options 100Stuck in Active 108Reducing Query Scope by Using Summary Routes 109Configuring EIGRP Summarization 110Determining the Summary Route 116Obtaining Default Route 120Load Balancing with EIGRP 123Configuring EIGRP Load Balancing 123EIGRP Load Balancing 124EIGRP Load Balancing Across Unequal-Metric Paths 126Configuring EIGRP for IPv6 128Overview of EIGRP for IPv6 128Configuring and Verifying EIGRP for IPv6 129EIGRP for IPv6 Configuration 130Determining the IPv6 Summary Route 134Named EIGRP Configuration 136Introduction to Named EIGRP Configuration 136Configuring Named EIGRP 137Address Families 139EIGRP for IPv4 Address Family 139EIGRP for IPv6 Address Family 142Named EIGRP Configuration Modes 148Classic Versus Named EIGRP Configuration 150Summary 151Review Questions 152Chapter 3 OSPF Implementation 155Establishing OSPF Neighbor Relationships 155OSPF Features 156OSPF Operation Overview 157Hierarchical Structure of OSPF 158Design Restrictions of OSPF 160OSPF Message Types 160Basic OSPF Configuration 161Optimizing OSPF Adjacency Behavior 170Using OSPF Priority in the DR/BDR Election 174OSPF Behavior in NBMA Hub-and-Spoke Topology 175The Importance of MTU 177Manipulating OSPF Timers 179OSPF Neighbor Relationship over Point-to-Point Links 182OSPF Neighbor Relationship over Layer 3 MPLS VPN 182OSPF Neighbor Relationship over Layer 2 MPLS VPN 184OSPF Neighbor States 184OSPF Network Types 186Configuring Passive Interfaces 187Building the Link-State Database 187OSPF LSA Types 188Examining the OSPF Link-State Database 189OSPF Link-State Database 190OSPF Type 2 Network LSA 196OSPF Type 3 Summary LSA 197OSPF Type 4 ASBR Summary LSA 199OSPF Type 5 External LSA 201Periodic OSPF Database Changes 203Exchanging and Synchronizing LSDBs 204Synchronizing the LSDB on Multiaccess Networks 206Running the SPF Algorithm 207Configuring OSPF Path Selection 208OSPF Path Selection 208OSPF Best Path Calculation 210Default OSPF Costs 211Calculating the Cost of Intra-Area Routes 214Calculating the Cost of Interarea Routes 214Selecting Between Intra-Area and Interarea Routes 215Optimizing OSPF Behavior 215OSPF Route Summarization 216Benefits of Route Summarization 217Configuring OSPF Route Summarization 218Summarization on ABRs 223Summarization on ASBRs 224OSPF Virtual Links 225Configuring OSPF Virtual Links 227Configuring OSPF Stub Areas 229OSPF Stub Areas 230OSPF Totally Stubby Areas 234Cost of the Default Route in a Stub Area 236The default-information originate Command 237Other Stubby Area Types 238OSPFv3 239Configuring OSPFv3 240Implementing OSPFv3 241OSPFv3 for IPv4 and IPv6 246Configuring Advanced OSPFv3 260OSPFv3 Caveats 261Summary 262Review Questions 263Chapter 4 Manipulating Routing Updates 267Using Multiple IP Routing Protocols on a Network 267Why Run Multiple Routing Protocols? 269Running Multiple Routing Protocols 269Administrative Distance 269Multiple Routing Protocols Solutions 270Implementing Route Redistribution 270Defining Route Redistribution 270Planning to Redistribute Routes 271Redistributing Routes 271Seed Metrics 272Default Seed Metrics 273Configuring and Verifying Basic Redistribution in IPv4 and IPv6 275Redistributing OSPFv2 Routes into the EIGRP Routing Domain 276Redistributing OSPFv3 Routes into the EIGRP for IPv6 Routing Domain 279Redistributing EIGRP Routes into the OSPFv2 Routing Domain 281Redistributing EIGRP for IPv6 Routes into the OSPFv3 Routing Domain 285Types of Redistribution Techniques 287One-Point Redistribution 287Multipoint Redistribution 288Redistribution Problems 289Preventing Routing Loops in a Redistribution Environment 291Verifying Redistribution Operation 292Controlling Routing Update Traffic 292Why Filter Routes? 292Route Filtering Methods 293Using Distribute Lists 294Configuring Distribute Lists 294Distribute List and ACL Example 295Using Prefix Lists 297Prefix List Characteristics 297Configuring Prefix Lists 298Distribute List and Prefix List Example 299Prefix List Examples 300Verifying Prefix Lists 301Manipulating Redistribution Using ACLs, Prefix Lists, and Distribute Lists 302Using Route Maps 305Understanding Route Maps 305Route Map Applications 305Configuring Route Maps 306Route Map Match and Set Statements 308Configuring Route Redistribution Using Route Maps 310Using Route Maps with Redistribution 310Manipulating Redistribution Using Route Maps 311Mutual Redistribution without Route Filtering 312Mutual Redistribution with Route Maps 313Change Administrative Distance to Enable Optimal Routing 315Manipulating Redistribution Using Route Tagging 318Caveats of Redistribution 319Summary 320References 323Review Questions 323Chapter 5 Path Control Implementation 327Using Cisco Express Forwarding Switching 327Control and Data Plane 328Cisco Switching Mechanisms 328Process and Fast Switching 332Cisco Express Forwarding 333Analyzing Cisco Express Forwarding 335Verify the Content of the CEF Tables 335Enable and Disable CEF by Interface and Globally 341Understanding Path Control 343The Need for Path Control 343Implementing Path Control Using Policy-Based Routing 344PBR Features 344Steps for Configuring PBR 345Configuring PBR 346Verifying PBR 348Configuring PBR Example 348Implementing Path Control Using Cisco IOS IP SLAs 354PBR and IP SLA 354IP SLA Features 354Steps for Configuring IP SLAs 356Verifying Path Control Using IOS IP SLAs 360Configuring IP SLA Example 361Configuring PBR and IP SLA Example 364Summary 369References 370Review Questions 370Chapter 6 Enterprise Internet Connectivity 373Planning Enterprise Internet Connectivity 374Connecting Enterprise Networks to an ISP 374Enterprise Connectivity Requirements 374ISP Redundancy 375Public IP Address Assignment 376The Internet Assigned Numbers Authority 376Regional Internet Registries 377Public IP Address Space 377Autonomous System Numbers 378Establishing Single-Homed IPv4 Internet Connectivity 381Configuring a Provider-Assigned IPv4 Address 381DHCP Operation 382Obtaining a Provider-Assigned IPv4 Address with DHCP 383Configuring a Router as a DHCP Server and DHCP Relay Agent 384NAT 385Configuring Static NAT 388Configuring Dynamic NAT 389Configuring PAT 390Limitations of NAT 392NAT Virtual Interface 393Configuring NAT Virtual Interface 393Verifying NAT Virtual Interface 396Establishing Single-Homed IPv6 Internet Connectivity 398Obtaining a Provider-Assigned IPv6 Address 398Manual Assignment 399Configuring Basic IPv6 Internet Connectivity 399Stateless Address Autoconfiguration 401DHCPv6 Operation 402Stateless DCHPv6 403Stateful DHCPv6 404DHCPv6 Prefix Delegation 405NAT for IPv6 405NAT64 405NPTv6 405IPv6 ACLs 405IPv6 ACL Characteristics 406Configuring IPv6 ACLs 406Securing IPv6 Internet Connectivity 409Improving Internet Connectivity Resilience 410Drawbacks of a Single-Homed Internet Connectivity 410Dual-Homed Internet Connectivity 410Dual-Homed Connectivity Options 411Configuring Best Path for Dual-Homed Internet Connectivity 411Multihomed Internet Connectivity 413Summary 415References 417Review Questions 418Chapter 7 BGP Implementation 423BGP Terminology, Concepts, and Operation 424BGP Use Between Autonomous Systems 424Comparison with Other Scalable Routing Protocols 425BGP Path Vector Characteristics 426BGP Characteristics 428BGP Tables 430BGP Message Types 431Open and Keepalive Messages 431Update Messages 433Notification Messages 433When to Use BGP 433When Not to Use BGP 434Implementing Basic BGP 435BGP Neighbor Relationships 435External BGP Neighbors 436Internal BGP Neighbors 437iBGP on All Routers in a Transit Path 438Basic BGP Configuration Requirements 442Entering BGP Configuration Mode 442Defining BGP Neighbors and Activating BGP Sessions 443Basic BGP Configuration and Verification 444Configuring and Verifying an eBGP Session 445Configuring and Verifying an iBGP Session 449Advertising Networks in BGP and Verifying That They Are Propagated 450Using the Next-Hop-Self Feature 457Understanding and Troubleshooting BGP Neighbor States 458BGP Session Resilience 460Sourcing BGP from Loopback Address 461eBGP Multihop 463Resetting BGP Sessions 464BGP Attributes and the Path-Selection Process 467