Introduction
Introduction to Networks Companion Guide (CCNAv7) is the official supplemental textbook for the Cisco Network Academy CCNA Introduction to Networks Version 7 course. Cisco Networking Academy is a comprehensive program that delivers information technology skills to students around the world. The curriculum emphasizes real-world practical application and provides opportunities to gain the skills and hands-on experience needed to design, install, operate, and maintain networks in small business, medium-sized business as well as enterprise and service provider environments.
This book provides a ready reference that explains the same networking concepts, technologies, protocols, and devices as the online curriculum. This book emphasizes key topics, terms, and activities and provides some alternative explanations and examples to supplement the course. You can use the online curriculum as directed by your instructor and then use this Companion Guide’s study tools to help solidify your understanding of all the topics.
Who Should Read This Book
The book, like the course it accompanies, is designed as an introduction to data network technology for those pursuing careers as network professionals as well as those who need an introduction to network technology for professional growth. Topics are presented concisely, starting with the most fundamental concepts and progressing to a comprehensive understanding of network communication. The content of this text provides the foundation for additional Cisco Networking Academy courses and preparation for the CCNA certification.
Book Features
The educational features of this book focus on supporting topic coverage, readability, and practice of the course material to facilitate your full understanding of the course material.
Topic Coverage
The following list gives you a thorough overview of the features provided in each chapter so that you can make constructive use of your study time:
Objectives: Listed at the beginning of each chapter, the objectives reference the core concepts covered in the chapter. The objectives match the objectives stated in the corresponding chapters of the online curriculum; however, the question format in the Companion Guide encourages you to think about finding the answers as you read the chapter.
Notes: These are short sidebars that point out interesting facts, timesaving methods, and important safety issues.
Summary: At the end of each chapter is a summary of the chapter’s key concepts. It provides a synopsis of the chapter and serves as a study aid.
Practice: At the end of chapter is a full list of all the labs, class activities, and Packet Tracer activities to refer to at study time.
Readability
The following features are provided to help you understand networking vocabulary:
Key terms: Each chapter begins with a list of key terms, along with a page-number reference to find the term used inside the chapter. The terms are listed in the order in which they are explained in the chapter. This handy reference allows you to find a term, flip to the page where the term appears, and see the term used in context. The Key Terms Glossary defines all the key terms.
Key Terms Glossary: This book contains an all-new Key Terms Glossary that defines more than 1000 terms.
Practice
Practice makes perfect. This Companion Guide offers you ample opportunities to put what you learn into practice. You will find the following features valuable and effective in reinforcing the instruction that you receive:
Check Your Understanding questions and answer key: Review questions are presented at the end of each chapter as a self-assessment tool. These questions match the style of questions in the online course. Appendix A, “Answers to ‘Check Your Understanding’ Questions,” provides an answer key to all the questions and includes an explanation of each answer.
Labs and activities: Throughout each chapter, you are directed back to the online course to take advantage of the activities provided to reinforce concepts. In addition, at the end of each chapter is a “Practice” section that lists all the labs and activities to provide practice with the topics introduced in this chapter.
Page references to online course: After most headings is a number in parentheses—for example, (1.1.2). This number refers to the page number in the online course so that you can easily jump to that spot online to view a video, practice an activity, perform a lab, or review a topic.
About Packet Tracer Software and Activities
Interspersed throughout the chapters, you’ll find a few Cisco Packet Tracer activities. Packet Tracer allows you to create networks, visualize how packets flow in a network, and use basic testing tools to determine whether a network would work. When you see this icon, you can use Packet Tracer with the listed file to perform a task suggested in this book. The activity files are available in the online course. Packet Tracer software is available only through the Cisco Networking Academy website. Ask your instructor for access to Packet Tracer.
How This Book Is Organized
This book corresponds closely to the Cisco Networking Academy CCNA IT Essential v7 course and is divided into 17 chapters, one appendix, and a glossary of key terms:
Chapter 1, “Networking Today”: This chapter introduces the concept of a network and provides an overview of the different types of networks encountered. It examines how networks impact the way we work, learn, and play. This chapter also examines recent trends in networks, such as video, cloud computing, and BYOD and how to help ensure robust, reliable, secure networks to support these trends.
Chapter 2, “Basic Switch and End Device Configuration”: This chapter introduces the operating system used with most Cisco devices: Cisco IOS. The basic purpose and functions of IOS are described, as are methods to access IOS. The chapter also describes how to maneuver through the IOS command-line interface as well as basic IOS device configuration.
Chapter 3, “Protocols and Models”: This chapter examines the importance of rules or protocols for network communication. It explores the OSI reference model and the TCP/IP communication suite and examines how these models provide the necessary protocols to allow communication to occur on a modern converged network.
Chapter 4, “Physical Layer”: This chapter introduces the lowest layer of the OSI model: the physical layer. This chapter explains the transmission of bits over the physical medium.
Chapter 5, “Number Systems”: This chapter explains how to convert between decimal, binary, and hexadecimal number systems. Understanding these number systems is essential to understanding IPv4, IPv6, and Ethernet MAC addressing.
Chapter 6, “Data Link Layer”: This chapter discusses how the data link layer prepares network layer packets for transmission, controls access to the physical media, and transports data across various media. This chapter includes a description of the encapsulation protocols and processes that occur as data travels across the LAN and the WAN.
Chapter 7, “Ethernet Switching”: This chapter examines the functionality of the Ethernet LAN protocols. It explores how Ethernet functions, including how devices use Ethernet MAC addresses to communicate in a multiaccess network. The chapter discusses how Ethernet switches build MAC address tables and forward Ethernet frames.
Chapter 8, “Network Layer”: This chapter introduces the function of the network layer—routing—and the basic device that performs this function—the router. It presents important routing concepts related to addressing, path determination, and data packets for both IPv4 and IPv6. The chapter also introduces how routers perform packet forwarding, static and dynamic routing, and the IP routing table.
Chapter 9, “Address Resolution”: This chapter discusses how host computers and other end devices determine the Ethernet MAC address for a known IPv4 or IPv6 address. This chapter examines the ARP protocol for IPv4 address resolution and the Neighbor Discovery Protocol for IPv6.
Chapter 10, “Basic Router Configuration”: This chapter explains how to configure a Cisco router, including IPv4 and IPv6 addressing on an interface.
Chapter 11, “IPv4 Addressing”: This chapter focuses on IPv4 network addressing, including the types of addresses and address assignment. It describes how to use subnet masks to determine the number of subnetworks and hosts in a network. It examines how to improve network performance by optimally dividing the IPv4 address space based on network requirements. It explores the calculation of valid host addresses and the determination of both subnet and broadcast addresses.
Chapter 12, “IPv6 Addressing”: This chapter focuses on IPv6 network addressing, including IPv6 address representation, types of addresses, and the structure of different types of IPv6 address. The chapter introduces the different methods that an end device can receive an IPv6 address automatically.
Chapter 13, “ICMP”: This chapter introduces Internet Control Message Protocol (ICMP) tools, such as ping and trace.
Chapter 14, “Transport Layer”: This chapter introduces Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) and examines how each of these protocols transports information across the network. It explores how TCP uses segmentation, the three-way handshake, and expectational acknowledg ments to ensure reliable delivery of data. It also examines the best-effort delivery mechanism provided by UDP and describes when its use would be preferred over the use of TCP.
Chapter 15, “Application Layer”: This chapter introduces some protocols of the TCP/IP application layer, which also relates to the top three layers of the OSI model. The chapter focuses on the role of the application layer and how the applications, services, and protocols in the application layer make robust communication across data networks possible. This will be demonstrated by examining some key protocols and services, including HTTP, HTTPS, DNS, DHCP, SMTP/POP, and FTP.
Chapter 16, “Network Security Fundamentals”: This chapter introduces network security threats and vulnerabilities. Various network attacks and mitigation techniques are discussed, along with how to secure network devices.
Chapter 17, “Build a Small Network”: This chapter reexamines the various components in a small network and describes how they work together to allow network growth. It examines network configuration and troubleshooting issues, along with different troubleshooting methodologies.
Appendix A, “Answers to ‘Check Your Understanding’ Questions”: This appendix lists the answers to the “Check Your Understanding” review questions that are included at the end of each chapter.
Key Terms Glossary: The Key Terms Glossary provides definitions for all the key terms identified in each chapter.