On 13 Feb 2020 I wrote the first one-page handout I still reuse: how to reach the bench router at 192.168.1.1 before we open Xcode. The class had lost twenty minutes because the lab switch had been power-cycled and nobody remembered the default gateway.

The handout is three steps. Confirm you are on the lab SSID, try the gateway in a browser, and if that fails check whether the router fell back to another private range. Only then do we talk about the app. It is not a networking course. It is the minimum so a phone can see a local server.

I kept the sheet because the same pause shows up in home labs, hotel Wi-Fi, and any desk where a firmware flash reset the admin password. The rest of this archive is code. This entry is the door you have to open first.