I’ve been creating a unit called “How the Internet Works” for my freshman classes. They did okay with the idea that every machine has an IP address. They figured out forward and reverse DNS lookups, although we did run into some problems when students didn’t have permission to open the command prompt and run nslookup. But I worked around that using some little utilities and using web-based lookup tools. They got the concepts, and I deemed that a success.
The next topics I want to get into are routing, subnets, and NAT. I’m not trying to go too crazy, just get them some basic familiarity with how TCP/IP works in real life. I was going to use email routing as an introduction to the concept of routing and to prompt more questions about IP addressing. The basic plan for my activity was to send an email to the class, have them look at the headers of that email, and figure out the route that the message took to get from my server to theirs. I’ve now attempted three variations on this activity with three different sections, and almost none of them really got it. I’m still trying to figure out why.
Here are some things I’ve noticed:
- Students almost universally don’t read the two paragraphs of explaination I wrote in the email.
- Many students clicked the links in my email without reading what I wanted them to do with those sites.
- Some students couldn’t figure out how to display headers on their webmail, despite step-by-step directions for each major email service. (This was not a huge deal, but it did suck up a lot of one-on-one time.)
- Students tried to find answers to questions like, “How many servers were involved in sending this email from me to you?” by searching the web. This one worries me.
- I lecture these classes very little, and write on the whiteboard very little, compared to my math classes last year.
- It’s really difficult to have discussions in a classroom where line-of-sight is obscured by computer monitors — there’s no place to stand where I can make eye contact with everyone at once, and most students can’t see most other students while seated.
I’m used to being able to refine a lesson so that it works within a few tries. But this has been a real flop, and I haven’t been able to fix it by tweaking the details. I’ve either pitched this way too high without giving enough conceptual support, or else I’m approaching the topic completely wrong. Any opinions?