HCNA Networking Study Guide

358 Pages·2016·22.94 MB·English

Huawei Technologies Co., Ltd.
HCNA
Networking
Study Guide
HCNA Networking Study Guide
Huawei Technologies Co., Ltd.
HCNA Networking Study
Guide
123
Huawei Technologies Co., Ltd.
Shenzhen
China
ISBN 978-981-10-1553-3 ISBN 978-981-10-1554-0 (eBook)
DOI 10.1007/978-981-10-1554-0
Library of Congress Control Number: 2016941304
© Springer Science+Business Media Singapore 2016
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Foreword
Huawei is one of the leading ICT solution providers worldwide. Our vision is to
enrich life through communication, and it is with this vision that we are able to
leverage our ICT technologies and experience to help everyone bridge the digital
divide and become a part of the information society so that all may enjoy the
benefits of ICT services. We endeavor to popularize ICT, facilitate education, and
cultivate ICT talents, providing people with the tools necessary to build a fully
connected world.
This book is a study guide for Huawei HCNA certification. It is the culmination
of efforts by Dr. Yonghong Jiang and his writing team. Dr. Jiang is a senior
technical expert in Huawei and has worked with us for over 10 years. Before
joining Huawei, Dr. Jiang gained many years of teaching experience in both
domestic and international universities. He therefore has a deep understanding of
how knowledge can be taught and mastered. Logic is important for explaining
principles, as too is the accuracy of information—the very essence of this is
embodied in HCNA Networking Study Guide. I truly believe it is a must-have book
for those who intend to learn HCNA network technologies.
March 2016 Wenjie Tu
Director of Global Training and Certification Department
Huawei Enterprise Business Group
v
Preface
Declaration
This book is the study guide for Huawei HCNA certification. It is crafted to help
understand the principles of network technologies. Apart from the knowledge
offered in this book, HCNA also covers other knowledge, such as RSTP, MSTP,
DNS, FTP, VRRP, NAC, 802.1x, SSH, xDSL, HDLC, FR, GRE, IPSec, WLAN,
VoIP, data center, cloud computing, 3G/4G, and IPv6. If you want a solid foundation
for preparing for the HCNA exam, you will also have to learn those concepts.
Organization of This Book
This book is divided up into 14 chapters. Chapters 1 and 2 are preparations for the
network technologies discussed in Chaps. 3–13. The last chapter, Chap. 14, is the
Appendix and provides answers to all review questions contained in the preceding
chapters.
Chapter 1 Network Communication Fundamentals
The OSI and TCP/IP models are vital to understanding network communication.
This chapter describes and compares the two models. It further introduces and
describes typical network topologies, LAN and WAN, transmission media, and
methods of communication.
Chapter 2 VRP Basics
VRP is Huawei’s network operating system that runs on network devices such as
routers and switches. Knowledge of VRP is essential to understanding Huawei
products and technologies, and many of the configuration examples provided in this
book are based on VRP. This chapter systematically introduces how to use VRP.
vii
viii Preface
Chapter 3 Ethernet
Ethernet is the most widely used type of LAN today, and as a result, the terms
Ethernet and LAN are almost synonymous. We start this chapter by introducing
Ethernet network interface cards on computers and switches and the differences
between them. We then discuss MAC addresses, Ethernet frames, switch for-
warding principles, MAC address tables, and ARP operating principles.
Chapter 4 STP
Layer 2 loops are a major problem on Ethernet networks covering both computers
and switches. Loop prevention protocols, such as STP, RSTP, and MSTP, can be
used on switches to prevent such loops. This chapter provides background infor-
mation about STP and describes how STP is used to prevent Layer 2 loops.
Chapter 5 VLAN
Another problem showing on Ethernet networks is how to flexibly and efficiently
classify Layer 2 broadcast domains. The solution to this problem is to use VLAN.
This chapter describes the VLAN principles, the format and forwarding process of
VLAN frames, and the link and port types used in VLAN. It also describes the
functions of GVRP.
Chapter 6 IP Basics
Chapters 3–5 focus on the data link layer. Chapter 6 describes IP basics, including
IP addressing, IP packet format, and IP forwarding. This chapter also addresses the
concepts of Layer 2 communication, Layer 3 communication, and the Internet.
Chapter 7 TCP and UDP
This chapter introduces the two transport layer protocols: TCP and UDP. It focuses
on the differences between connectionless and connection-oriented communication.
It also demonstrates how a TCP session is created and terminated, and presents the
acknowledgment and retransmission mechanisms of TCP.
Chapter 8 Routing Protocol Basics
Knowledge of routing and routing protocols is the basis to understand networking
and its technologies. This chapter starts by introducing basic concepts, such as a
route’s composition, static and dynamic routes, and routing tables. It then describes
RIP, the simplest routing protocol. This chapter also introduces the concepts of
OSPF.
Preface ix
Chapter 9 Inter-VLAN Layer 3 Communication
Computers on different VLANs cannot communicate over Layer 2, but they can
communicate over Layer 3. This chapter describes the working principles of
inter-VLAN Layer 3 communication through a one-armed router, a multi-armed
router, and a Layer 3 switch. It covers the contents of how a Layer 3 switch, a Layer
2 switch, and a conventional router forward data.
Chapter 10 Link Technologies
Link aggregation is a commonly used link technology that can flexibly increase
bandwidth and improve connecting reliability among various network devices. This
chapter includes the basic concepts, application scenarios, and working principles
of link aggregation. It also involves two Huawei proprietary link technologies that
can improve network link reliability: Smart Link and Monitor Link.
Chapter 11 DHCP and NAT
This chapter describes the basic concepts and working process of DHCP as well as
DHCP relay. It also introduces the basic concepts, principles, and application
scenarios of NAT.
Chapter 12 PPP and PPPoE
This chapter describes the basic concepts and working process of PPP, the format of
PPP frames, and the different phases involved in PPP. It further elaborates the
combination between PPP and Ethernet, known as PPPoE.
Chapter 13 Network Management and Security
Management and security are vital concerns in today’s networks. This chapter
concentrates on SMI, MIB, and SNMP used in network management and ACL used
in network security.
Chapter 14 Appendix—Answers to Review Questions
Many sections in each chapter of this book include review questions for the readers
to oversee the contents they have studied. The suggested answers to these review
questions are provided throughly in this chapter.
Target Audience
This book is targeted to the readers preparing for Huawei HCNA certification. It
covers the detailed basis of routing and switching technologies, which also makes it
a valuable resource for ICT practitioners, university students, and network tech-
nology fans.
x Preface
Important Notes
While reading this book, please be aware of the following:
1. This book may refer to some concepts which are beyond its scope. We advise
you to research these concepts for the better understanding but doing so is not a
requirement.
2. The Ethernet mentioned in this book only refers to the star-type Ethernet net-
works. This book does not include bus-type Ethernet or such related concepts as
CSMA/CD and collision domain. Many resources are available to be traced by
most of the search engines if you are interested in Ethernet’s history and its
development.
3. Unless otherwise specifically explained, IP in this book refers to IPv4. IPv6 is
not covered in this book.
4. This book presents two data link layer technologies, Ethernet and PPP. Unless
otherwise stated, network interface cards, network interfaces, interfaces, and
ports specifically stand for Ethernet network interface cards, Ethernet network
interfaces, Ethernet interfaces, and Ethernet ports, respectively, and frames refer
to Ethernet frames.
5. In this book, the network interfaces on routers and computers are noted as
interfaces and the network interfaces on switches are noted as ports.
6. Unless otherwise stated, switches in this book refer to Layer 2 Ethernet switches
that do not support Layer 3 forwarding.
7. In Sect. 8.1.2, we state that the cost of a static route can be set to 0 or any
desired value. This is true theoretically, but most network device vendors
require the cost of a static route to be only 0 and do not allow it to be configured
or changed. In addition, many such vendors set the minimum number of RIP
hops as 0, meaning that there is no hop from a RIP router to its directly
connected network. However, the Routing Information Protocol itself stipulates
that there be a minimum of 1 hop from a RIP router to its directly connected
network. This difference exists due to historical factors, but does not affect the
deployment and functions of RIP. In Sects. 8.2.1–8.2.7, the minimum number of
RIP hops is thus defined as 1. In Sect. 8.2.8, the minimum number of RIP hops
is defined as 0.
8. If you have any feedback or suggestions regarding this book, please e-mail Huawei
at
Preface xi
Icons in This Book
Router Access Aggregation Core
switch switch switch
Server PC IP-DSLAM HG
Network cloud Internet Ethernet or PPP link (Ethernet by
default)