@grainloom You'd definitely build the switches and routers. Maybe spawn the world with a fixed "gateway" block and you have to implement your own switches and routers around it. Then you can implement BGP to, well, do what BGP does, really. routing and stuff.
@grainloom Complete OSI model simulator. From hardware to software. And all of it internet-connected, so you can access your simulation from the outside world, like it exists IRL - as a proper simulation should be.
(Am I going too far? Maybe? Just a bit?)