Interconnecting Cisco Network Devices, Part 1 (ICND1) Foundation Learning Guide / Edition 4

by Anthony Sequeira

Overview

This Cisco-authorized, self-paced foundation learning tool for both the CCENT 100-101 and CCNA® 200-120 exams offers a comprehensive overview of the diverse technologies found in modern internetworks. From routing and switching concepts to practical configuration and security, it teaches with numerous examples, illustrations, and real-world scenarios, helping you rapidly gain both expertise and confidence.

This book provides you with all the knowledge you need to install, operate and troubleshoot a small enterprise branch network, including basic network security. Whether you are preparing for certification or simply want to understand basic Cisco networking, you’ll find this guide exceptionally valuable. Topics covered include: TCP/IP models and protocols; LANs and Ethernet; running Cisco IOS; VLANs and trunks; IP addressing and subnetting; packet delivery; static and dynamic routing; DHCP and NAT; network security; WANs, IPv6, and more.

This edition has been fully updated to reflect the new Cisco ICND1 100-101 exam blueprint. Content has been reorganized, simplified, and expanded to help you learn even more efficiently. New Production Network Simulation questions offer more real-world review, and new web video resources in each chapter walks you through many key tasks.

Interconnecting Cisco Network Devices, Part 1 (ICND1) Foundation Learning Guide, Fourth Edition is part of a recommended learning path from Cisco that includes simulation and hands-on training from authorized Cisco Learning Partners and self-study products from Cisco Press. To find out more about instructor-led training, e-learning, and hands-on instruction from authorized Cisco Learning Partners worldwide, please visit www.cisco.com/go/authorizedtraining.

• Network functions, components, models, layers, topologies, and applications
• LAN, Ethernet, switching, routing, and packet delivery concepts
• Network management with Cisco IOS software and its command-line interface
• VLANs and segmentation: techniques for optimizing performance and flexibility
• Easy ways to create efficient IP addressing and subnetting schemes
• Cisco router configuration, including static and dynamic routing
• DHCP and NAT: dynamically providing IP addresses and handling limited address availability
• Essential network security techniques
• Traffic management with Access Control Lists
• WAN concepts, technologies, and options
• IPv6 configuration in dynamically routed network environments

Product Details

ISBN-13:	9781587143762
Publisher:	Pearson Education
Publication date:	06/17/2013
Series:	Foundation Learning Guides Series
Edition description:	New Edition
Pages:	560
Product dimensions:	7.50(w) x 9.20(h) x 1.40(d)

About the Author

Anthony Sequeira, CCIE No. 15626, is a seasoned trainer and author regarding all levels and tracks of Cisco certification. Anthony formally began his career in the information technology industry in 1994 with IBM in Tampa, Florida. He quickly formed his own computer consultancy, Computer Solutions, and then discovered his true passion—teaching and writing about Microsoft and Cisco technologies.

Anthony joined Mastering Computers in 1996 and lectured to massive audiences around the world about the latest in computer technologies. Mastering Computers became the revolutionary online training company, KnowledgeNet, and Anthony trained there for many years.

Anthony is currently pursuing his second CCIE in the area of security and then his third Cisco Data Center! When not writing for Cisco Press, Anthony is a full-time instructor for the next-generation of KnowledgeNet, StormWind.com.

Anthony is an avid tennis player, is a private pilot, and enjoys getting beaten up by women and children at his and his daughter’s martial arts school, www.sparta.fm .

Table of Contents

Introduction xxi

Chapter 1 The Functions of Networking 1

Chapter Objectives 2

What Is a Network? 2

Physical Components of a Network 4

Interpreting a Network Diagram 5

Network User Applications 7

Impact of User Applications on the Network 8

Characteristics of a Network 10

Physical Versus Logical Topologies 11

Physical Topologies 11

Logical Topologies 12

Bus Topology 13

Star and Extended-Star Topologies 14

Star Topology 14

Extended-Star Topology 15

Ring Topologies 16

Single-Ring Topology 16

Dual-Ring Topology 17

Mesh and Partial-Mesh Topologies 17

Full-Mesh Topology 17

Partial-Mesh Topology 18

Connections to the Internet 18

Chapter 2 The OSI and TCP/IP Models 25

Chapter Objectives 26

Understanding the Host-to-Host Communications Model 26

The OSI Reference Model 27

Layer 7: The Application Layer 29

Layer 6: The Presentation Layer 29

Layer 5: The Session Layer 29

Layer 4: The Transport Layer 30

Layer 3: The Network Layer 30

Layer 2: The Data Link Layer 31

Layer 1: The Physical Layer 31

The Data Communications Process 31

Encapsulation 32

Deencapsulation 33

Peer-to-Peer Communication 34

The TCP/IP Protocol Stack 35

OSI Model Versus TCP/IP Stack 36

Chapter 3 LANs and Ethernet 43

Chapter Objectives 44

Understanding LANs 44

The Definition of a LAN 44

Components of a LAN 45

Functions of a LAN 46

How Big Is a LAN? 47

Ethernet 48

Ethernet LAN Standards 48

LLC Sublayer 49

MAC Sublayer 49

The Role of CSMA/CD in Ethernet 49

Ethernet Frames 50

Ethernet Frame Addressing 52

Ethernet Addresses 52

MAC Addresses and Binary-Hexadecimal Numbers 53

Connecting to an Ethernet LAN 54

Ethernet Network Interface Cards 54

Ethernet Media and Connection Requirements 55

Connection Media 55

Unshielded Twisted-Pair Cable 57

UTP Implementation 58

Auto-MDIX 62

Optical Fiber 62

Chapter 4 Operating Cisco IOS Software 69

Chapter Objectives 70

Cisco IOS Software Features and Functions 70

Cisco IOS CLI Functions 71

Configuring Network Devices 72

External Configuration Sources 73

Entering the EXEC Modes 75

Help in the CLI 77

Enhanced Editing Commands 79

Command History 81

Managing Cisco IOS Configuration 81

Improving the User Experience in the CLI 84

Chapter 5 Switch Technologies 89

Chapter Objectives 90

The Need for Switches 90

Switch Characteristics 92

Starting and Configuring a Switch 93

Switch Installation 93

Switch LED Indicators 93

Connecting to the Console Port 94

Basic Switch Configuration 95

Verifying the Switch Initial Startup Status 97

Switching Operation 99

Duplex Communication 100

Troubleshooting Common Switch Media Issues 102

Media Issues 102

Port Issues 106

Chapter 6 VLANs and Trunks 111

Chapter Objectives 112

Implementing VLANs and Trunks 112

Issues in a Poorly Designed Network 112

VLAN Overview 114

Understanding Trunking with 802.1Q 115

802.1Q Frame 116

802.1Q Native VLAN 117

Understanding VLAN Trunking Protocol 118

VTP Modes 118

VTP Operation 119

VTP Pruning 120

Configuring VLANs and Trunks 121

VTP Configuration 122

Example: VTP Configuration 122

802.1Q Trunking Configuration 123

VLAN Creation 126

VLAN Port Assignment 128

Adds, Moves, and Changes for VLANs 129

Adding VLANs and Port Membership 129

Changing VLANs and Port Membership 130

Deleting VLANs and Port Membership 130

VLAN Design Considerations 130

Physical Redundancy in a LAN 131

Routing Between VLANs 133

Understanding Inter-VLAN Routing 133

Example: Router on a Stick 134

Example: Subinterfaces 135

Configuring Inter-VLAN Routing Using Router on a Stick 135

Using Multilayer (Layer 3) Switches 136

Chapter 7 The TCP/IP Internet Layer 139

Chapter Objectives 140

Understanding TCP/IP’s Internet Layer 140

IP Network Addressing 140

IP Address Classes 143

Network and Broadcast Addresses 145

Public and Private IP Addresses 149

Address Exhaustion 150

Addressing Services 153

Dynamic Host Configuration Protocol 154

Domain Name System 155

Using Common Host Tools to Determine the IP Address of a Host 155

Chapter 8 IP Addressing and Subnets 161

Chapter Objectives 161

Understanding Binary Numbering 162

Decimal and Binary Systems 162

Least Significant Bit and Most Significant Bit 163

Base 2 Conversion System 164

Powers of 2 164

Decimal-to-Binary Conversion 165

Binary-to-Decimal Conversion 166

Constructing a Network Addressing Scheme 167

Subnetworks 167

Two-Level and Three-Level Addresses 169

Subnet Creation 170

Computing Usable Subnetworks and Hosts 170

Computing Hosts for a Class C Subnetwork 170

Computing Hosts for a Class B Subnetwork 171

Computing Hosts for a Class A Subnetwork 172

How End Systems Use Subnet Masks 173

How Routers Use Subnet Masks 174

Mechanics of Subnet Mask Operation 176

Applying Subnet Mask Operation 178

Determining the Network Addressing Scheme 179

Class C Example 180

Class B Example 181

Class A Example 183

Implementing Variable-Length Subnet Masks 184

Introducing VLSMs 184

Route Summarization with VLSM 187

Chapter 9 The TCP/IP Transport Layer 195

Chapter Objectives 195

Understanding TCP/IP’s Transport Layer 196

The Transport Layer 196

TCP/IP Applications 199

Transport Layer Functionality 200

TCP/UDP Header Format 202

How TCP and UDP Use Port Numbers 204

Establishing a TCP Connection: The Three-Way Handshake 205

Session Multiplexing 208

Segmentation 209

Flow Control for TCP/UDP 209

Acknowledgment 210

Windowing 211

Fixed Windowing 211

Example: Throwing a Ball 212

TCP Sliding Windowing 213

Maximize Throughput 214

Global Synchronization 214

Chapter 10 The Functions of Routing 219

Chapter Objectives 220

Exploring the Functions of Routing 220

Routers 220

Path Determination 222

Routing Tables 223

Routing Table Information 223

Routing Update Messages 224

Static, Dynamic, Directly Connected, and Default Routes 224

Dynamic Routing Protocols 225

Routing Metrics 225

Routing Methods 226

Chapter 11 The Packet Delivery Process 233

Chapter Objectives 233

Exploring the Packet Delivery Process 234

Layer 1 Devices and Their Functions 234

Layer 2 Devices and Their Functions 234

Layer 2 Addressing 235

Layer 3 Devices and Their Functions 236

Layer 3 Addressing 236

Mapping Layer 2 Addressing to Layer 3 Addressing 237

ARP Table 238

Host-to-Host Packet Delivery 238

Function of the Default Gateway 247

Using Common Host Tools to Determine the Path Between Two Hosts Across a Network 248

Chapter 12 Configuring a Cisco Router 255

Chapter Objectives 255

Starting a Cisco Router 256

Initial Startup of a Cisco Router 256

Initial Setup of a Cisco Router 257

Logging In to the Cisco Router 263

Showing the Router Initial Startup Status 266

Summary of Starting a Cisco Router 267

Configuring a Cisco Router 267

Cisco Router Configuration Modes 268

Configuring a Cisco Router from the CLI 269

Configuring Cisco Router Interfaces 271

Configuring the Cisco Router IP Address 272

Verifying the Interface Configuration 273

Verifying the Interface Configuration 277

Chapter 13 Static Routing 285

Chapter Objectives 285

Enabling Static Routing 286

Routing Overview 286

Static and Dynamic Route Comparison 287

Static Route Configuration 288

Example: Understanding Static Routes 288

Example: Configuring Static Routes 289

Default Route Forwarding Configuration 290

Static Route Verification 290

Chapter 14 Dynamic Routing Protocols 293

Chapter Objectives 294

Dynamic Routing Protocol Overview 294

Features of Dynamic Routing Protocols 296

Example: Administrative Distance 296

Classful Routing Versus Classless Routing Protocols 297

Distance Vector Route Selection 299

Example: Distance Vector Routing Protocols 299

Example: Sources of Information and Discovering Routes 300

Understanding Link-State Routing Protocols 300

Link-State Routing Protocol Algorithms 304

Chapter 15 OSPF 311

Chapter Objectives 311

Introducing OSPF 312

Establishing OSPF Neighbor Adjacencies 313

SPF Algorithm 315

Configuring and Verifying OSPF 316

Loopback Interfaces 317

Verifying the OSPF Configuration 318

Load Balancing with OSPF 326

OSPF Authentication 328

Types of Authentication 328

Configuring Plaintext Password Authentication 329

Example: Plaintext Password Authentication Configuration 330

Verifying Plaintext Password Authentication 331

Troubleshooting OSPF 332

Components of Troubleshooting OSPF 332

Troubleshooting OSPF Neighbor Adjacencies 333

Troubleshooting OSPF Routing Tables 336

Troubleshooting Plaintext Password Authentication 337

Chapter 16 DHCP and NAT 343

Chapter Objectives 343

Using a Cisco Router as a DHCP Server 344

Understanding DHCP 344

DHCPDISCOVER 344

DHCPOFFER 345

DHCPREQUEST 345

DHCPACK 345

Configuring a Cisco Router as a DHCP Client 345

Using a Cisco Router as a DHCP Server 345

Using a Cisco Router as a DHCP Relay Agent 347

Scaling the Network with NAT and PAT 347

Introducing NAT and PAT 348

Translating Inside Source Addresses 350

Static NAT Address Mapping 353

Dynamic Address Translation 354

Overloading an Inside Global Address 355

Resolving Translation Table Issues 359

Resolving Issues by Using the Correct Translation Entry 362

Chapter 17 Securing the Network 371

Chapter Objectives 372

Securing the Network 372

Need for Network Security 372

Balancing Network Security Requirements 375

Adversaries, Hacker Motivations, and Classes of Attack 376

Classes of Attack 376

Mitigating Common Threats 377

Physical Installations 377

Reconnaissance Attacks 378

Access Attacks 379

Password Attacks 379

Understanding Cisco Device Security 380

Physical and Environmental Threats 380

Configuring Password Security 380

Configuring the Login Banner 382

Telnet Versus SSH Access 383

Port Security Configuration on Switches 384

Securing Unused Ports 387

Chapter 18 Managing Traffic with Access Control Lists 391

Chapter Objectives 392

Access Control List Operation 392

Understanding ACLs 392

ACL Operation 395

Types of ACLs 398

ACL Identification 398

Additional Types of ACLs 401

Dynamic ACLs 401

Reflexive ACLs 402

Time-Based ACLs 404

ACL Wildcard Masking 405

Configuring ACLs 408

Configuring Numbered Standard IPv4 ACLs 408

Example: Numbered Standard IPv4 ACL—Permit My Network Only 409

Example: Numbered Standard IPv4 ACL—Deny a Specific Host 410

Example: Numbered Standard IPv4 ACL—Deny a Specific Subnet 411

Controlling Access to the Router Using ACLs 413

Configuring Numbered Extended IPv4 ACLs 413

Extended ACL with the established Parameter 416

Numbered Extended IP ACL: Deny FTP from Subnets 417

Numbered Extended ACL: Deny Only Telnet from Subnet 418

Configuring Named ACLs 419

Creating Named Standard IP ACLs 420

Creating Named Extended IP ACLs 421

Named Extended ACL: Deny a Single Host from a Given Subnet 422

Named Extended ACL—Deny a Telnet from a Subnet 424

Adding Comments to Named or Numbered ACLs 425

Troubleshooting ACLs 425

Problem: Host Connectivity 427

Chapter 19 Introducing WAN Technologies 433

Chapter Objectives 433

Introducing WANs 434

WANs Versus LANs 435

The Role of Routers in the WAN 437

WAN Communication Link Options 437

Point-to-Point Connectivity 438

Configuring a Point-to-Point Link 438

Chapter 20 Introducing IPv6 441

Chapter Objectives 441

Overview of IPv6 442

IPv6 Features and Addresses 443

IPv6 Address Types 444

IPv6 Address Allocation Options 446

IPv6 Header Changes and Benefit