A Practical Walkthrough of a Surprisingly Hard Problem

For a task that sounded trivial at first, this experiment turned into a surprisingly deep dive into Android networking limitations, routing constraints, VPN behavior, and how Bluetooth Personal Area Networking (PAN) actually works under the hood.

My goal sounded simple:

Connect an Android phone to my Linux laptop over Bluetooth PAN and route ALL traffic from the phone to the Internet through the laptop — without Wi-Fi, without mobile data, without USB tethering, and without root.

Easy peasy.