计算机网络实验报告-实验五 探索TCP协议.doc
《计算机网络实验报告-实验五 探索TCP协议.doc》由会员分享,可在线阅读,更多相关《计算机网络实验报告-实验五 探索TCP协议.doc(23页珍藏版)》请在沃文网上搜索。
1、西范大学陕师西范大学陕师 算机网 计络 算机网 计络告实验报告实验报实验五 探索实验五 探索 TCPTCP 协议协议一、实验目的一、实验目的 1.熟悉并掌握 wireshark的操作。2.通过实验分析并掌握TCP 是如何进行数据传输的,及其如何实现拥塞控制、流量控制等二、实验器材二、实验器材 1.PC机电脑一台。2下载 wireshark软件并安装三、实验内容三、实验内容通过实验分析并掌握 TCP是如何进行数据传输的,及其如何实现拥塞控制、流量控制等四、问题回答四、问题回答1.Capturing a bulk TCP transfer from your computer to a remot
2、eServer1Go the http:/gaia.cs.umass.edu/wiresharklabs/alice.txt and retrieve an ASCII copy of Alice in Wonderland.Store this file.somewhere on my computer.Next go to http:/gaia.cs.umass.edu/wireshark-labs/TCP-wireshark-file1.html.Then I cansee a screen that looks like:,2start up Wireshark and begin p
3、acket capture.Returning to browser,press the“Upload alice.txt file”button to upload the file to the gaia.cs.umass.edu server.Stop Wireshark packet capture.The Wireshark window like this:Then opening the Wireshark captured packet file tcpethereal-trace-1 in http:/gaia.cs.umass.edu/wireshark-labs/wire
4、shark-traces.zip2.A first look at the captured trace1.What is the IP address and TCP port number used by the client computer(source)that is transferring the file to gaia.cs.umass.edu?To answer this question,itsprobably easiest to select an HTTP message and explore the details of the TCPpacket used t
5、o carry this HTTP message,using the“details of the selected packetheader window”(refer to Figure 2 in the“Getting Started with Wireshark”Lab ifyoure uncertain about the Wireshark windows).答:client computer(source):IP address:192.168.1.1023ip addressTcp port numberTCP port number:11612.What is the IP
6、 address of gaia.cs.umass.edu?On what port number is it sendingand receiving TCP segments for this connection?答:the IP address of gaia.cs.umass.edu:IP address:128.119.245.12port number:803.If you have been able to create your own trace,answer the following question:Whatis the IP address and TCP port
7、 number used by your client computer(source)to transferthe file to gaia.cs.umass.edu?4ip address:port number答:My client computer:IP address:10.2.136.305ip address:Tcp port numberThen Wireshark do this,select Analyze-Enabled Protocols.Then uncheck the HTTP box andselect OK.now see an Wireshark window
8、 that looks like:3.TCP BasicsAnswer the following questions;4.What is the sequence number of the TCP SYN segment that is used to initiate theTCP connection between the client computer and gaia.cs.umass.edu?What is itin the segment that identifies the segment as a SYN segment?6Sequence numberSyn is 1
9、答:sequence number:0;syn 被设置为1说明是syn 段。5.What is the sequence number of the SYNACK segment sent by gaia.cs.umass.eduto the client computer in reply to the SYN?What is the value of the ACKnowledgementfield in the SYNACK segment?How did gaia.cs.umass.edu determine that value?Whatis it in the segment th
10、at identifies the segment as a SYNACK segment?答:The sequence number of the SYNACK segment sent by gaia.cs.umass.edu is:0;SYNACK segment 中 ACKnowledgement 的值为1;ACKnowledgement number 的值为 SYN 消息中 sequence number 加上 1所得;SYN 和Acknowledgement f 都置为 1说明这是一个 SYNACK segment.6.What is the sequence number of
11、the TCP segment containing the HTTP POSTcommand?Note that in order to find the POST command,youll need to dig intothe packet content field at the bottom of the Wireshark window,looking for asegment with a“POST”within its DATA field.7Sequence numberThe value of the ACKnowledgement field8Sequence numb
12、erPost commandNO.4 segment答:第四号报文段是包含 HTTP POST 命令的 TCP segment.且报文段的序列号为 1.7.Consider the TCP segment containing the HTTP POST as the first segment in theTCP connection.What are the sequence numbers of the first six segments in theTCPconnection(including the segment containing the HTTP POST)?At wha
13、t time was eachsegment sent?When was the ACK for each segment received?Given the differencebetween when each TCP segment was sent,and when itsacknowledgement wasreceived,what is the RTT value for each of the sixsegments?What is the EstimatedRTTvalue(see page 249 in text)after thereceipt of each ACK?
14、Assume that the value of theEstimatedRTT is equal tothe measured RTT for the first segment,and then is computedusing theEstimatedRTT equation on page 249 for all subsequent segments.Note:Wireshark has a nice feature that allows you to plot the RTT foreach of the TCPsegments sent.Select a TCP segment
15、 in the“listing ofcaptured packets”window that isbeing sent from the client to thegaia.cs.umass.edu server.Then select:Statistics-TCPStream Graph-Round Trip Time Graph.9Segment 1-6 areNo.4,5,7,8,10Segment 1Segment 2Segment 3Segment 410Sequence number=1Sequence number=566Sequence number=2026Segment 5
16、Segment 6答:前 6 个 报 文 段 为 No.4,5,7,8,10,11.对 应 的 ACK 分 别 为No.6,9,12,14,15,16.前6 个报文段截图如下:11Sequence number=3486Sequence number=4946Sequence number=6406报文段的序列号为每个报文段的首字节加 1,所以序列号为:Segment 1 sequence number:1Segment 2 sequence number:566Segment 3 sequence number:2026Segment 4 sequence number:3486Segmen
17、t 5 sequence number:4946Segment 6 sequence number:6406报文段的发送时间和相应ACK 的到达时间如下表::Send timeACK received timeRTT secondsSegment 10.0264770.0539370.02746Segment 20.0417370.0772940.035557Segment 30.0540260.1240850.070059Segment 40.0546900.1691180.11443Segment 50.0774050.2172990.13989Segment 60.0781570.267
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10 积分
下载 | 加入VIP,下载更划算! |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 计算机网络实验报告-实验五 探索TCP协议 计算机网络 实验 报告 探索 TCP 协议