The mini internet project is part of the curriculum by the Networked Systems Group of ETH Zurich. It teaches the students the basic steps how to create a mini internet. It starts with the basics of intra-network routing, by setting up multiple L2 switches. Then the students have to configure L3 routers to connect multiple L2 sites together. Lastly, in a big hackathon style, the students need to connect their local network with the network of the other students, by properly configuring BGP routers and setting up routing policies.
The code and the tasks are all available in the GitHub repository.
The APNIC Blog has a nice introduction to the project too.