dn42: A Volunteer-Run Internet Inside the Internet

Field notes

dn42 uses ordinary Internet protocols inside a volunteer-run overlay: participants establish tunnels, receive private address space, and exchange routes with BGP. The public wiki documents multiple tunnel methods and routing stacks, from WireGuard and GRE to Bird2, FRRouting, OpenBGPD, and RouterOS. Its stated scale—more than 1,500 autonomous systems and 1,700 prefixes—makes it more than a toy lab, while the private address ranges keep experiments separate from the public Internet.