Table of Contents

Introduction xxv


Assessment Test l


Part I ICND1 1


Chapter 1 Internetworking 3


Internetworking Basics 4


Internetworking Models 13


The OSI Reference Model 15


Summary 31


Exam Essentials 31


Written Labs 32


Review Questions 36


Chapter 2 Ethernet Networking and Data Encapsulation 41


Ethernet Networks in Review 42


Ethernet Cabling 59


Data Encapsulation 66


The Cisco Three-Layer Hierarchical Model 69


Summary 72


Exam Essentials 73


Written Labs 74


Review Questions 79


Chapter 3 Introduction to TCP/IP 85


Introducing TCP/IP 86


TCP/IP and the DoD Model 87


IP Addressing 116


IPv4 Address Types 123


Summary 127


Exam Essentials 127


Written Labs 129


Review Questions 131


Chapter 4 Easy Subnetting 135


Subnetting Basics 136


Summary 166


Exam Essentials 166


Written Labs 167


Review Questions 170


Chapter 5 VLSMs, Summarization, and Troubleshooting TCP/IP 175


Variable Length Subnet Masks (VLSMs) 176


Summarization 186


Troubleshooting IP Addressing 189


Summary 196


Exam Essentials 197


Written Lab 5 198


Review Questions 199


Chapter 6 Cisco’s Internetworking Operating System (IOS) 205


The IOS User Interface 206


Command-Line Interface (CLI) 209


Administrative Configurations 218


Router and Switch Interfaces 231


Viewing, Saving, and Erasing Configurations 240


Summary 255


Exam Essentials 256


Written Lab 6: IOS Understanding 259


Hands-on Labs 259


Review Questions 267


Chapter 7 Managing a Cisco Internetwork 273


The Internal Components of a Cisco Router and Switch 274


Backing Up and Restoring the Cisco Configuration 276


Configuring DHCP 280


Syslog 283


Network Time Protocol (NTP) 288


Exploring Connected Devices Using CDP and LLDP 289


Using Telnet 298


Resolving Hostnames 302


Checking Network Connectivity and Troubleshooting 306


Summary 311


Exam Essentials 311


Written Labs 7 313


Hands-on Labs 314


Review Questions 319


Chapter 8 Managing Cisco Devices 323


Managing the Configuration Register 324


Backing Up and Restoring the Cisco IOS 331


Summary 348


Exam Essentials 348


Written Lab 8 349


Hands-on Labs 350


Review Questions 352


Chapter 9 IP Routing 357


Routing Basics 359


The IP Routing Process 361


Configuring IP Routing 372


Configuring IP Routing in Our Network 381


Dynamic Routing 390


Routing Information Protocol (RIP) 392


Summary 399


Exam Essentials 399


Written Lab 9 400


Review Questions 405


Chapter 10 Layer 2 Switching 411


Switching Services 412


Configuring Catalyst Switches 422


Summary 433


Exam Essentials 433


Written Lab 10 434


Hands-on Labs 434


Review Questions 438


Chapter 11 VLANs and Inter-VLAN Routing 443


VLAN Basics 444


Identifying VLANs 449


Routing between VLANs 454


Configuring VLANs 456


Summary 472


Exam Essentials 472


Written Lab 11 473


Hands-on Labs 473


Review Questions 477


Chapter 12 Security 483


Perimeter, Firewall, and Internal Routers 484


Introduction to Access Lists 485


Standard Access Lists 489


Extended Access Lists 497


Monitoring Access Lists 508


Summary 510


Exam Essentials 511


Written Lab 12 511


Hands-on Labs 512


Review Questions 517


Chapter 13 Network Address Translation (NAT) 521


When Do We Use NAT? 522


Types of Network Address Translation 524


NAT Names 524


How NAT Works 525


Testing and Troubleshooting NAT 529


Summary 535


Exam Essentials 535


Written Lab 13 535


Hands-on Labs 536


Review Questions 542


Chapter 14 Internet Protocol Version 6 (IPv6) 547


Why Do We Need IPv6? 549


The Benefits and Uses of IPv6 549


IPv6 Addressing and Expressions 551


How IPv6 Works in an Internetwork 555


IPv6 Routing Protocols 565


Configuring IPv6 on Our Internetwork 566


Configuring Routing on Our Internetwork 569


Summary 572


Exam Essentials 573


Written Labs 14 573


Hands-on Labs 574


Review Questions 577


Part II ICND2 581


Chapter 15 Enhanced Switched Technologies 583


VLAN Review 584


VLAN Trunking Protocol (VTP) 593


Configuring VTP 597


Spanning Tree Protocol (STP) 602


Types of Spanning-tree Protocols 610


Modifying and Verifying the Bridge ID 618


Spanning-Tree Failure Consequences 623


PortFast and BPDU Guard 625


EtherChannel 629


Summary 634


Exam Essentials 635


Written Lab 15 635


Hands-on Labs 636


Review Questions 643


Chapter 16 Network Device Management and Security 649


Mitigating Threats at the Access Layer 650


External Authentication Options 653


SNMP 655


Client Redundancy Issues 659


Introducing First Hop Redundancy Protocols (FHRPs) 661


Hot Standby Router Protocol (HSRP) 662


Summary 675


Exam Essentials 675


Written Lab 16 676


Review Questions 677


Chapter 17 Enhanced IGRP 681


EIGRP Features and Operations 682


Configuring EIGRP 690


Verifying and Troubleshooting EIGRP 709


EIGRPv6 727


Summary 732


Exam Essentials 733


Written Lab 17 733


Hands-on Labs 734


Review Questions 737


Chapter 18 Open Shortest Path First (OSPF) 745


Open Shortest Path First (OSPF) Basics 746


Configuring OSPF 753


OSPF and Loopback Interfaces 762


Verifying OSPF Configuration 765


Summary 771


Exam Essentials 771


Written Lab 18 772


Hands-on Labs 772


Review Questions 776


Chapter 19 Multi-Area OSPF 783


OSPF Scalability 784


Categories of Multi-area Components 786


Basic Multi-area Configuration 793


Verifying and Troubleshooting Multi-area OSPF Networks 796


Troubleshooting OSPF Scenario 804


OSPFv3 814


Summary 819


Exam Essentials 819


Written Lab 19 820


Hands-on Labs 820


Review Questions 826


Chapter 20 Troubleshooting IP, IPv6, and VLANs 831


Troubleshooting IP Network Connectivity 832


Troubleshooting IPv6 Network Connectivity 850


Troubleshooting VLAN Connectivity 862


Summary 874


Exam Essentials 875


Written Lab 20 875


Review Questions 877


Chapter 21 Wide Area Networks 881


Introduction to Wide Area Networks 882


Cabling the Serial Wide Area Network 894


High-Level Data-Link Control (HDLC) Protocol 896


Point-to-Point Protocol (PPP) 898


Virtual Private Networks 913


GRE Tunnels 919


Single-Homed EBGP 925


Summary 934


Exam Essentials 934


Written Lab 21 935


Hands-on Labs 935


Review Questions 941


Chapter 22 Evolution of Intelligent Networks 947


Switch Stacking 948


Cloud Computing and Its Effect on the Enterprise Network 950


Overview of Network Programmability in Enterprise Network 953


Application Programming Interfaces (APIs) 954


Cisco APIC-EM 957


Cisco Intelligent WAN 960


Quality of Service 962


Trust Boundary 964


QoS Mechanisms 965


Summary 971


Exam Essentials 971


Written Lab 22 971


Review Questions 973


Appendix A Answers to Written Labs 977


Chapter 1: Internetworking 978


Chapter 2: Ethernet Networking and Data Encapsulation 980


Chapter 3: Introduction to TCP/IP 983


Chapter 4: Easy Subnetting 984


Chapter 5: VLSMs, Summarization and Troubleshooting TCP/IP 986


Chapter 6: Cisco’s Internetworking Operating System (IOS) 986


Chapter 7: Managing a Cisco Internetwork 987


Chapter 8: Managing Cisco Devices 988


Chapter 9: IP Routing 988


Chapter 10: Layer 2 Switching 989


Chapter 11: VLANs and InterVLAN Routing 989


Chapter 12: Security 990


Chapter 13: Network Address Translation (NAT) 991


Chapter 14: Internet Protocol Version 6 (IPv6) 991


Chapter 15: Enhanced Switched Technologies 992


Chapter 16: Network Device Management and Security 993


Chapter 17: Enhanced IGRP 993


Chapter 18: Open Shortest Path First (OSPF) 994


Chapter 19: Multi-Area OSPF 994


Chapter 20: Troubleshooting IP, IPv6, and VLANs 995


Chapter 21: Wide Area Networks 995


Chapter 22: Evolution of Intelligent Networks 996


Appendix B Answers to Review Questions 997


Chapter 1: Internetworking 998


Chapter 2: Ethernet Networking and Data Encapsulation 1000


Chapter 3: Introduction to TCP/IP 1002


Chapter 4: Easy Subnetting 1003


Chapter 5: VLSMs, Summarization, and Troubleshooting TCP/IP 1005


Chapter 6: Cisco’s Internetworking Operating System (IOS) 1007


Chapter 7: Managing a Cisco Internetwork 1009


Chapter 8: Managing Cisco Devices 1010


Chapter 9: IP Routing 1012


Chapter 10: Layer 2 Switching 1013


Chapter 11: VLANs and InterVLAN Routing 1015


Chapter 12: Security 1017


Chapter 13: Network Address Translation (NAT) 1019


Chapter 14: Internet Protocol Version 6 (IPv6) 1020


Chapter 15: Enhanced Switched Technologies 1022


Chapter 16: Network Device Management and Security 1024


Chapter 17: Enhanced IGRP 1025


Chapter 18: Open Shortest Path First (OSPF) 1027


Chapter 19: Multi-Area OSPF 1029


Chapter 20: Troubleshooting IP, IPv6, and VLANs 1031


Chapter 21: Wide Area Networks 1032


Chapter 22: Evolution of Intelligent Networks 1033


Appendix C Disabling and Configuring Network Services 1037


Blocking SNMP Packets 1038


Disabling Echo 1038


Turning off BootP and Auto-Config 1039


Disabling the HTTP Interface 1040


Disabling IP Source Routing 1040


Disabling Proxy ARP 1040


Disabling Redirect Messages 1040


Disabling the Generation of ICMP Unreachable Messages 1041


Disabling Multicast Route Caching 1041


Disabling the Maintenance Operation Protocol (MOP) 1041


Turning Off the X.25 PAD Service 1042


Enabling the Nagle TCP Congestion Algorithm 1042


Logging Every Event 1042


Disabling Cisco Discovery Protocol 1043


Disabling the Default Forwarded UDP Protocols 1043


Cisco’s auto secure 1044


Index 1047

About the Author

Todd Lammle, Cisco certified in almost every category, is the authority on Cisco networking and certification. His three decades of real-world experience is prevalent in his writing. He is an experienced networking engineer with very practical experience working on the largest bounded and unbounded networks in the world at such companies as Xerox, Hughes Aircraft, Texaco, AAA, Cisco, and Toshiba, among many others. Todd has published over 60 books, including the very popular and bestselling CCNA: Cisco Certified Network Associate Study Guide and Cisco Firepower NGIPS. Todd runs an international training company from Texas, and a large scale consulting business out of Colorado. You can reach Todd through his forum and blog at www.lammle.com/ccna.