本选题基于Cisco Packet Tracer网络仿真软件，并依据TCP/IP协议的分层模型进行实验设计。本书*章介绍了Packet Tracer6.0使用指南，第二至六章给出了相关实验，依次为数据链路层实验、网络层协议实验、传输层实验、应用层实验、网络安全实验及综合实验。其中，每部分实验包括背景知识、实验目的、实验配置说明、实验步骤，以及相关的思考题。

计算机网络是信息技术各专业的重要基础课程之一。以Internet 为代表的计算机网络已经发展成一个极其庞大的信息系统，涉及众多复杂的网络协议和算法。而且这些协议和技术大多被网络采用的分层设计方法所屏蔽和封装起来，比较抽象，不利于读者理解和学习。所以，能观察和分析协议原理的实验是学习计算机网络必不可少的实践环节，本书编写的目的就在于此。本书设计的所有实验均在Cisco Packet Tracer 网络模拟系统上进行。该软件是由Cisco 公司发布的一个网络辅助学习工具，其最大的优点是能采用动画方式表现网络协议过程和数据封装，这对读者进一步理解网络的工作原理和体系结构有很大的帮助。在实验内容上，本书以跟踪数据在网络中的传输过程、捕获和分析数据传输中产生的数据包为主；在实验设计上，本书紧扣计算机网络教学中的重点、难点，通过学生亲自动手操作实验或者教师演示实验，使复杂抽象的网络概念、网络协议的学习和教学变得形象生动，有助于学习者理解和掌握相关的概念和协议。全书分为7 章，第1 章主要介绍Packet Tracer 的基本操作方法。第2～6 章围绕计算机网络系统中数据链路层、网络层、运输层、网络安全及应用层的主要协议，精心设计了27 个实验。第7 章给出两个综合实验，一个涉及垂直协议栈，其目的是让读者深入理解Internet 的工作原理和各层协议间的协作关系；另一个涉及三层组网技术，其目的是让读者理解网络工程中流量优化和高可靠等设计方法。与第一版相比，第二版增加了无线网络、网络安全和三层组网等8 个新内容，并对多数实验进行了优化和调整，学习效果更优。在章节结构上，本书各实验均介绍和归纳了所涉及的背景知识，因此，本书既可作为计算机网络课程的配套实验用书，也可单独作为自学教材使用。针对每个实验，作者都亲自动手完成并反复验证，并在书中给出了详细的实验操作步骤，确保实验内容的正确性及实验的可操作性。在每个实验之后，还给出了相关思考题，以进一步加强读者对知识点的理解。本书第1、6 章由赖会霞编写，第2 章由赖会霞和陈秋玲合作编写，第3 章由叶阿勇编写，第4、5 章由张桢萍编写，第7 章由叶阿勇和赖会霞合作编写，叶阿勇负责全书内容的选材和统稿工作，许力教授审阅了全书。此外，本书附有各实验的配套电子文档和教学课件，读者可从华信教育资源网下载。另外，本书所有实验用例文件均基于Cisco Packet Tracer 6.2版本，请读者在进行实验时使用Packet Tracer 6.2 或以上版本打开用例文件。
由于作者水平所限，书中难免存在不足和疏漏之处，恳请广大读者和同行批评指正。
作者的联系电子邮箱：yay@fjnu.edu.cn。
作 者2017 年7 月于福建师范大学长安山

现任福建师范大学数计学院网络与信息安全教研室主任，硕导，中国计算机学会会员，ACM会员。目前的研究方向：理论研究方面：网络通信、网络安全、信息系统等领域；应用研究方面：系统安全、基于wifi定位系统。主持多项国家级项目，发表多篇文章。

第1 章 Packet Tracer 6.2 使用指南 ······························································ 1
1.1 Packet Tracer 6.2 概述 ······································································· 1
1.2 Packet Tracer 6.2 操作界面 ······························································· 1
1.2.1 菜单栏 ···················································································· 2
1.2.2 拓扑工作区 ············································································ 4
1.2.3 设备列表区 ············································································ 5
1.3 使用Packet Tracer 6.2 搭建网络拓扑 ·············································· 6
1.3.1 添加网络设备 ········································································ 6
1.3.2 添加设备模块 ········································································ 8
1.3.3 连接网络设备 ······································································ 10
1.4 使用Packet Tracer 配置网络 ························································· 12
1.4.1 图形化配置界面配置网络设备 ··········································· 13
1.4.2 命令行接口CLI ··································································· 14
1.4.3 PC 的配置 ············································································ 18
1.5 使用Packet Tracer 进行协议分析 ················································· 19
1.5.1 Packet Tracer 操作模式 ······················································· 19
1.5.2 添加PDU ············································································· 22
1.5.3 查看协议数据包 ··································································· 23
第2 章 数据链路层实验 ·············································································· 25
2.1 实验一：PPP 与PPPoE 学习 ························································· 25
2.1.1 背景知识 ·············································································· 25
2.1.2 实验目的 ·············································································· 27
2.1.3 实验配置说明 ······································································ 27
2.1.4 实验步骤 ·············································································· 28
2.1.5 思考题 ·················································································· 34
2.2 实验二：以太网帧的封装实验 ······················································ 34
2.2.1 背景知识 ·············································································· 34
2.2.2 实验目的 ·············································································· 36
2.2.3 实验配置说明 ······································································ 36
2.2.4 实验步骤 ·············································································· 37
2.2.5 思考题 ·················································································· 39
2.3 实验三：集线器与交换机的对比实验 ·········································· 39
2.3.1 背景知识 ·············································································· 39
2.3.2 实验目的 ·············································································· 40
2.3.3 实验配置说明 ······································································ 41
2.3.4 实验步骤 ·············································································· 42
2.3.5 思考题 ·················································································· 45
2.4 实验四：交换机工作原理 ······························································ 46
2.4.1 背景知识 ·············································································· 46
2.4.2 实验目的 ·············································································· 47
2.4.3 实验配置说明 ······································································ 47
2.4.4 实验步骤 ·············································································· 48
2.4.5 思考题 ·················································································· 51
2.5 实验五：生成树协议（STP）分析 ··············································· 51
2.5.1 背景知识 ·············································································· 51
2.5.2 实验目的 ·············································································· 52
2.5.3 实验配置说明 ······································································ 52
2.5.4 实验步骤 ······················································