9-12, Advanced Topics, AP Computer Science Principles

Exploring Network Traffic with Wireshark

Monitoring the network requests through the developer tools in Chrome, has been part of my Internet unit for awhile now.  Students are fascinated watching the requests scroll by and investigating all the data being sent just to load the webpage.  This year, I stepped it up a notch and downloaded Wireshark to monitor all the traffic on the Wifi network at school.  Wireshark has a zillion features, and I don’t understand or pretend to understand what most of it means. (And modelling that for the students is important!)  But, on the first day of our Internet unit, I displayed the software on the projector and asked the students, “What do you notice? What do you wonder?”  I was blown away by their responses and questions and thrilled to be able to gather an understanding of their existing knowledge while previewing many of the concepts and discussions we’ll have in this unit.  Some highlights:

  • Students recognized the names of some of their schoolmates’ laptops making requests and were able to identify which hotspot they were connected to and, perhaps, their location on campus.  Resulting in many responding “thats so creepy!” and a brief privacy discussion.
  • A student wondered, “why do they all have the same letters under “Protocol?”  This led to the class arriving at their own definition of protocol and why there might be different ones for different requests.  Some Googled the acronyms to find out more information.
  • Double-clicking on a request opens up a window that has a packet number as it’s title.  From here, we were able to discuss what purpose a packet serves.  One student recognized that the information included in that packet was hexadecimal which helped remind us that every piece of data is transmitted in binary.
  • Students wondered why they were seeing so many of the same numbers making requests consecutively.  After many speculations about whether people on campus were rapid-firing Googling, I explained at a high level the many requests that go into the transfer of even a small piece of information.
  • The “Who has…?” broadcast messages allowed us to discuss DNS and how the Internet is organized.
  • And once they were good and shocked about how much is going on beyond the scenes, we defined abstraction!

I will admit, I’m very lucky that this is a small class that is willing to wonder out loud.  If you’re not sure that your students would be so willing to openly discuss, you could have them complete a scavenger hunt in small groups and revisit each “find” as you discuss them throughout the unit.  An attention-grabbing start to the unit and the school year!