I may have misused the word dorm. It is a shared appartment rented with a couple other students.

My goal is basically to set up a private network inside the network used by the other people I share the apartment with so I can tinker with stuff like setting my own DNS server up for the network without possibly impacting the other people in case of failure. My naive impression was that I would need to use a VLAN to accomplish that.

In regards to your idea of using multiple devices I kind of agree but I want to keep the initial cost and energy usage low for now which is why I am trying to find a device I can use for this but also reuse in the future for something else if I want to upgrade (or just retire it without too much sunk cost).