lab1

1. Is your browser running HTTP version 1.0 or 1.1 ? What version of HTTP is the server running?
2. What languages (if any) does your browser indicate that it can accept to the server?
3. What is the IP address of your computer? Of the gaia.cs.umass.edu server?
4. What is the status code returned from the server to your browser?
5. When was the HTML file that you are retrieving last modified at the server?
6. How many bytes of content are being returned to your browser?
7. By inspecting the raw data in the packet content window, do you see any headers within the data that are not displayed in the packet-listing window? If so, name one.

answer

问题1：

我的浏览器使用的http是1.1版本

服务器运行的http版本也是1.1

问题2

支持的语言为中文和英文

问题3

我的IP为192.168.1.11 目标ip为128.119.245.12

问题4

状态码：200

问题5

2024年4月8日 05：59：01

问题6

返回了128字节

问题7

在原始数据包内容窗口中检查数据时，可以看到一些在数据包列表窗口中未显示的头部信息。例如：

lab2

8. Inspect the contents of the first HTTP GET request from your browser to the server. Do you see an "IF-MODIFIED-SINCE" line in the HTTP GET?
9. Inspect the contents of the server response. Did the server explicitly return the contents of the file? How can you tell?
10. Now inspect the contents of the second HTTP GET request from your browser to the server. Do you see an "IF-MODIFIED-SINCE:" line in the HTTP GET? If so, what information follows the "IF-MODIFIED-SINCE:" header?
11. What is the HTTP status code and phrase returned from the server in response to this second HTTP GET? Did the server explicitly return the contents of the file? Explain.

问题8

在第一次的HTTP GET请求中没有“IF-MODIFIED-SINCE”，但是在第一次的响应报文中存在又Last-Modified用于保存文件最后一次修改的时间

问题9

是显示的返回文件的内容，在响应报文中能直接看到

问题10

if-modified-since后面写的是服务器中网页的最后更新时间

问题11

状态码是304 短语是Not Modified，服务器并未显示的返回文件的内容，因为现在的文件和缓存服务器中的文件并未产生变化，所以，直接从缓存服务器中得到文件即可，没必要从web服务器返回文件，占用带宽

lab3

12. How many HTTP GET request messages did your browser send? Which packet number in the trace contains the GET message for the Bill or Rights?
13. Which packet number in the trace contains the status code and phrase associated with the response to the HTTP GET request?
14. What is the status code and phrase in the response?
15. How many data-containing TCP segments were needed to carry the single HTTP response and the text of the Bill of Rights?

问题12

一共只发送了一个http get报文。从第212个packet中包含Get message，第213个是第一个数据包

问题13

第213个中包含了状态码和响应报文

问题14

问题15

分别使用一个报文来承载get和ok（一共两个），四个TCP报文段来承载数据。

因为第一个和第6个len都是0，且ip地址能反应出数据的流向

后面4个tcp都能传输数据

lab4

16. How many HTTP GET request messages did your browser send? To which Internet addresses were these GET requests sent?
17. Can you tell whether your browser downloaded the two images serially, or whether they were downloaded from the two web sites in parallel? Explain.

问题16

发送了3个http get的消息，分别从上到下发送给了

[Full request URI: http://gaia.cs.umass.edu/wireshark-labs/HTTP-wireshark-file4.html]

[Full request URI: http://gaia.cs.umass.edu/pearson.png]

[Full request URI: http://kurose.cslash.net/8E_cover_small.jpg]

问题17

我认为是并行下载的，因为第一张图片并没有获得返回信息，浏览器就发送了对第二张图片的get报文

lab5

HTTP Authentication Schemes的内容在下面的链接中有解释

http://frontier.userland.com/stories/storyReader$2159

18. What is the server’s response (status code and phrase) in response to the initial HTTP GET message from your browser?
19. When your browser’s sends the HTTP GET message for the second time, what new field is included in the HTTP GET message?

问题18