Tài liệu Todd Lammle’s CCNA ® IOS ® Command Survival Guide pptx

Wiley Publishing, Inc.

Todd Lammle’s

CCNA® IOS® Command

Survival Guide

Todd Lammle

75606ffirs.fm Page i Tuesday, October 23, 2007 3:24 PM

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Wiley Publishing, Inc.

Todd Lammle’s

CCNA® IOS® Command

Survival Guide

Todd Lammle

75606ffirs.fm Page i Tuesday, October 23, 2007 3:24 PM

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Dear Reader

Thank you for choosing Todd Lammle’s CCNA IOS Command Survival Guide. This book

is part of a family of premium quality Sybex books, all written by outstanding authors who

combine practical experience with a gift for teaching.

Sybex was founded in 1976. More than thirty years later, we’re still committed to producing

consistently exceptional books. With each of our titles we’re working hard to set a new stan￾dard for the industry. From the paper we print on, to the authors we work with, our goal

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Acknowledgments

Kudos to Jeff Kellum for coming up with the idea for this book. This was one of my favorite

books I have written.

Thanks to Lisa Thibault for her patience and gentle but effective direction and also thanks

to Eric Charbonneau for helping me organize and keep my thoughts going in one direction—

which is no easy task! Also, thanks to Pat Conlan for his technical expertise. Finally, thanks

to copy editor Kim Wimpsett, proofreader Amy McCarthy, and compositor Craig Johnson;

all of who helped to create this fantastic title.

About the Author

Todd Lammle, CCSI, CCNA/CCNP/CCSP, MCSE, CEH/CHFI, FCC RF Licensed, is the

authority on Cisco Certification internetworking. He is a world renowned author, speaker,

trainer and consultant. Todd has over 25 years of experience working with LAN’s, WAN’s

and large licensed and unlicensed Wireless networks. He is president of GlobalNet Training

and Consulting, Inc., a network integration and training firm based in Dallas. You can reach

Todd through his forum at www.lammle.com.

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Contents at a Glance

Introduction xiii

Chapter 1 Basic IOS Commands 1

Chapter 2 Managing a Cisco Internetwork 21

Chapter 3 IP Routing 57

Chapter 4 Enhanced IGRP (EIGRP) and Open Shortest Path First (OSPF) 75

Chapter 5 Layer-2 Switching and Spanning-Tree Protocol (STP) 101

Chapter 6 Virtual LANs (VLANs) 121

Chapter 7 Security 137

Chapter 8 Network Address Translation (NAT) 161

Chapter 9 Cisco’s Wireless Technologies 175

Chapter 10 Internet Protocol Version 6 (IPv6) 199

Chapter 11 Wide Area Networks (WANs) 219

Chapter 12 Cisco’s Security Device Manager (SDM) 249

Index 279

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Contents

Introduction xiii

Chapter 1 Basic IOS Commands 1

Booting the Router 2

Setup Mode 4

Router Configuration Modes 4

Editing and Help Features 6

Configuring a Router 9

Hostnames 9

Banners 9

Passwords 10

Router Interfaces 14

Using the show Command 18

Chapter 2 Managing a Cisco Internetwork 21

Understanding the Internal Components of a Cisco Router 22

Managing the Configuration Register 23

Checking the Current Configuration Register Value 24

Changing the Configuration Register 24

Recovering Passwords 26

Using Boot System Commands 29

Backing Up and Restoring the Cisco IOS 30

Verifying Flash Memory 30

Backing Up the Cisco IOS 31

Restoring or Upgrading the Cisco Router IOS 32

Using the Cisco IOS File System (Cisco IFS) 32

Backing Up and Restoring the Cisco Configuration 35

Backing Up the Cisco Router Configuration 35

Restoring the Cisco Router Configuration 37

Erasing the Configuration 38

Using the Cisco IOS File System to Manage

Your Router’s Configuration (Cisco IFS) 38

Using Cisco Discovery Protocol (CDP) 40

Getting CDP Timers and Holdtime Information 40

Gathering Neighbor Information 41

Gathering Interface Traffic Information 43

Gathering Port and Interface Information 43

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viii Contents

Using Telnet 44

Telnetting into Multiple Devices Simultaneously 45

Checking Telnet Connections 46

Checking Telnet Users 46

Closing Telnet Sessions 47

Resolving Hostnames 48

Building a Host Table 49

Using DNS to Resolve Names 51

Checking Network Connectivity and Troubleshooting 52

Using the ping Command 52

Using the traceroute Command 53

Debugging 53

Using the sh processes Command 55

Chapter 3 IP Routing 57

Routing Basics 58

Static Routing 61

Default Routing 63

Routing Protocol Basics 65

Administrative Distances (ADs) 65

Routing Information Protocol (RIP) 66

RIP Timers 67

Enabling RIP 68

Holding Down RIP Propagations 69

RIP Version 2 (RIPv2) 69

Verifying RIP 71

The show ip protocols Command 71

The debug ip rip Command 72

Chapter 4 Enhanced IGRP (EIGRP) and

Open Shortest Path First (OSPF) 75

Understanding EIGRP Basics 76

Configuring EIGRP 77

Holding Down EIGRP Propagations 77

Setting Maximum Paths and Hop Count 78

Using Redistribution Commands 79

Configuring Discontiguous Networks 81

Load Balancing with EIGRP 81

Using Route Authentication with EIGRP 85

Verifying EIGRP 86

Understanding Open Shortest Path First (OSPF) Basics 90

Configuring OSPF 91

Enabling OSPF 92

Configuring OSPF Areas 92

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Contents ix

Verifying OSPF Configuration 92

Using the show ip ospf Command 94

Using the show ip ospf database Command 95

Using the show ip ospf interface Command 95

Using the show ip ospf neighbor Command 96

Using the show ip protocols Command 97

Debugging OSPF 98

Chapter 5 Layer-2 Switching and

Spanning-Tree Protocol (STP) 101

Switching Services 102

Three Switch Functions at Layer 2 103

Basic Switch Configurations 104

Switch Security 105

Spanning-Tree Operations 107

Optimizing Spanning-Tree Operations 108

EtherChannel 112

Verifying Cisco Catalyst Switches 114

Chapter 6 Virtual LANs (VLANs) 121

Understanding VLAN Basics 122

Configuring VLANs 122

Verifying VLAN Creation 124

Assigning Switch Ports to VLANs 124

Configuring Trunk Ports 126

Configuring Inter-VLAN Routing 130

Configuring VTP 131

Telephony: Configuring Voice VLANs 134

Configuring the Voice VLAN 134

Chapter 7 Security 137

Perimeter Routers, Firewalls, and Internal Routers 138

Recognizing Security Threats 139

Using Cisco IOS Firewall 140

Introduction to Access Lists 141

Standard Access Lists 143

Wildcard Masking 145

Controlling VTY (Telnet) Access 145

Extended Access Lists 146

Named Access Lists 151

Switch Port ACLs 153

Time-Based ACLs 156

Monitoring Access Lists 158

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x Contents

Chapter 8 Network Address Translation (NAT) 161

When Do We Use NAT? 162

Types of Network Address Translation 163

NAT Names 164

Static NAT Configuration 165

Dynamic NAT Configuration 166

PAT (Overloading) Configuration 167

Simple Verification of NAT 168

Configuring NAT Using SDM 170

Chapter 9 Cisco’s Wireless Technologies 175

Introducing Wireless Technology 176

The 802.11 Standards 178

Service Sets 182

Wireless Security 184

Configuring Cisco Wireless Using the IOS 186

AP Configuration 189

Configuring Cisco Wireless Using the SDM/HTTP 190

Chapter 10 Internet Protocol Version 6 (IPv6) 199

Why Do We Need IPv6? 200

IPv6 Addressing and Expressions 201

Shortened Expression 202

Configuring Cisco Routers with IPv6 203

DHCPv6 204

IPv6 Routing Protocols 206

RIPng 206

EIGRPv6 207

OSPFv3 208

Migrating to IPv6 209

Dual Stacking 210

6to4 Tunneling 211

Verifying RIPng 212

Verifying OSPFv3 215

Chapter 11 Wide Area Networks (WANs) 219

Introduction to Wide Area Networks 220

Defining WAN Terms 221

WAN Support 221

High-Level Data-Link Control (HDLC) Protocol 224

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Contents xi

Point-to-Point Protocol (PPP) 225

Configuring PPP on Cisco Routers 226

Configuring PPP Authentication 227

Verifying PPP Encapsulation 228

PPPoE Configuration 233

Introduction to Frame Relay Technology 235

Frame Relay Encapsulation Types 236

Data Link Connection Identifiers (DLCIs) 237

Local Management Interface (LMI) 238

Frame Relay Implementation and Monitoring 241

Chapter 12 Cisco’s Security Device Manager (SDM) 249

Configuring Your Router to Be Set Up Through the SDM 250

Using the SDM to Manage the Flash Memory 259

Using the SDM to Back Up, Restore, and Edit the

Router’s Configuration 262

Configuring LAN and Wan Interfaces and Verifying a

Router Using SDM 266

Configuring RIP on a Router with SDM 272

EIGRP 274

Configuring OSPF with the SDM 275

Index 279

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