• Name: Qi Yi Yang
  • Student ID: 201821121019
  • Class: calculated 1811

table of Contents

1 Purpose

  • Using different network router
  • Use the command line router
  • By grabbing HTTP packets, TCP connection establishment process analysis

2 Experimental content

Use Packet Tracer, properly configure the network parameters, by crawling HTTP packets, analyzes the TCP connection establishment procedure.

  • Establish a network topology
  • Configuration parameters
  • Ethereal
  • Analysis of the data packet

3. The test report

Before writing the report, read: submit jobs to some of the considerations of the class blog .

Experimental reporting requirements: independently, not plagiarism. Submitted before the deadline.

Your personal information is given at the beginning of Bowen

  • Full name
  • student ID
  • class

3.1 Establish a network topology

Network topology as shown below:

3.2 Configuration Parameters

PC end

 

 

server

 

 

 

Details are given operating parameters of the router, to explain the function of each command.

 

 

Router> enable # to enter the privileged EXEC mode
• Router # configure terminal # enter the global configuration mode
• Router (config) #hostname R # router name is configured to R
• Configure G0 / 0 Interface:
• R(config)#interface G0/0
• R(config-if)#ip address 192.168.1.20 255.255.255.0
• R (config-if) #no shutdown # interface to activate

 

 

 

 

 

Enable Dynamic Routing
• R(conf)# router rip
• R(conf)#version 2 使用rip 2版本
• R(conf)#no auto-summary 关闭自动路由汇总
• 指定网络
• R(conf)#network 192.168.1.0
• R(conf)#network 192.168.2.0

 

 

 

 

3.3 抓包，分析TCP连接建立过程

建立连接

抓包

 

HTTP报文

 

 

TCP报文：

 

IP报文

 

 

 

 

 

 

 

 

 

 

（1）画出TCP连接建立示意图

如下图所示：

（2）解答：为什么连接建立需要第三次握手

 为了保证服务端能收接受到客户端的信息并能做出正确的应答而进行前两次(第一次和第二次)握手，

为了保证客户端能够接收到服务端的信息并能做出正确的应答而进行后两次(第二次和第三次)握手

双方连接的建立可以会失败，若不加以确认，错误的连接会保留，并导致资源浪费，所以需要三握手，来确认连接是否成功。