I.e., a file that includes other objects (in the example below, image files) that are stored on Here we look at what happens when your browser downloads a file with embedded objects,

Second HTTP GET? Did the server explicitly return the contents of the file? Explain Q8: What is the HTTP status code and phrase returned from the server in response to this Q7: Now inspect the contents of the second HTTP GET request from your browser to the server.ĭo you see an 'IF-MODIFIED-SINCE:' line in the HTTP GET? If so, what information follows Did the server explicitly return the contents of Q6: Inspect the contents of the server response.

See an 'IF-MODIFIED-SINCE' line in the HTTP GET? Q5: Inspect the contents of the first HTTP GET request from your browser to the server. That only captured HTTP messages will be displayed later in the packet-listing window. Stop Wireshark packet capture, and enter 'http' in the display-filter-specification window, so Quickly enter the same URL into your browser again (or simply select the refresh button on Your browser should display a very simple five-line HTML file Enter the following URL into your browser Start up your web browser, and make sure your browser's cache is cleared, as discussedĬ. Before performing the steps below, make sure your browser'sĪ. Recall that most web browsers perform object caching and thus perform a conditional GET The HTTP CONDITIONAL GET/response interaction. Q4: How many bytes of content are being returned to your browser?Ģ. Q3: When was the HTML file that you are retrieving last modified at the server? Q2: What is the status code returned from the server to your browser? Q1: Is your browser running HTTP version 1.0 or 1.1? What version of HTTP is the server Your browser should display the very simple, one-line HTML file. Wait a bit more than one minute and then begin Wireshark packet capture. To see the clutter of all captured packets).Ĭ. (We're only interested in the HTTP protocol here, and don't want Enter 'http' (just the letters, not the quotation marks) in the display-įilter-specification window, so that only captured HTTP messages will be displayed later in Start up the Wireshark packet sniffer, as described in the Introductory lab (but don't yetīegin packet capture). The Basic HTTP GET/response interaction.ī.

Src port wireshark