HTTP

I: Basic HTTP GET/ Response messages:

Empty your browser’s cache. 
Open the Wireshark tool and start capturing the packets. 
Open the browser and type: http://gaia.cs.umass.edu/wireshark-labs/HTTP-wireshark-file2.html 
Stop capturing the packets and type http in the Wireshark filter text box. Close your browser but do not close the Wireshark tool.

Answer the following questions:

1. (4 pts) What HTTP version is your browser and the gaia.cs.umass.edu server running? HTTP Version 1.1

2. (4 pts) What language your browser can accept from the server? en-US, en

3. (4 pts) What is the status code the server has returned to your browser? What does that status code mean? 200 Ok

4. (4 pts) What is the size of the content in terms of bytes? 784

Give the screenshot of the captured packets in Wireshark similar to the one below.

II. HTTP conditional GET/ Response messages:

Empty your browser’s cache once again. 
Start capturing the packets using Wireshark tool. 
Open the browser and type http://gaia.cs.umass.edu/wireshark-labs/HTTP-wireshark-file2.html 
Refresh your browser by clicking the “Refresh” button after a few seconds. 
Stop capturing the packets and type http in the Wireshark filter text box. 

Answer the following questions:

1. (4 pts) Check the first HTTP GET request from the browser to the server. Is there any IF-MODIFIED-SINCE line in the HTTP GET? No

2. (4 pts) Now check the second HTTP GET request from the browser to the server. Can you see the IF-MODIFIED-SINCE line in the HTTP GET request now? If yes, then what information follows it? Yes, it has the date and time for the first request. After this line is a IF-None-Match, and i think its a code

3. (4 pts) What is the HTTP status code returned from the server? What does that status code mean? 304 Not Modified

Close your browser. Give the screenshot of the captured packets in Wireshark.

III. Retrieving HTML document with embedded objects:

Open your browser and empty your browser’s cache once again. 
Start capturing the packets using Wireshark tool. 
Type the following URL in your browser: http://gaia.cs.umass.edu/wireshark-labs/HTTP-wireshark-file4.html 
Stop capturing the packets and type http in the Wireshark filter text box. 

Answer the following questions:

1. (4 pts) How many GET request messages have been sent from the browser? 4

2. (4 pts) To which Internet addresses are these GET requests sent? gaia.cs.umass.edu , kurose.cslash.net

3. (4 pts) Are the two images downloaded serially or from the two websites in parallel. How could you say so? The two images are downloaded serially. If you if we look at the times where the requests left our computer we can tell that the request were sent at different times. meaning that they are not downloaded in parallel

Give the screenshot of the captured packets in Wireshark, but do not close the Wireshark because those captured packets will be used for next section.