There could be a test of the users' knowledge about auto tunneling methods like 6to4 and Teredo.

For example show the user a few addresses and for each address they have to classify it as: 6to4, Teredo, or something else.

For 6to4 they should be able to identify the IPv4 address of the gateway. For Teredo they should be able to identify the IPv4 address of server as well as client.

Another test could involve demonstrating knowledge of what can be done to work around flaky 6to4 or Teredo connectivity. There could be a webserver hosted on a slightly broken 6to4 or Teredo connection, and the user would have to find a way to get a code from a page on that server. I'm not sure exactly how the brokenness should look like to be both an interesting scenario and still possible to solve.