n2n is a lightweight open-source VPN that creates virtual networks between computers behind firewalls and NAT devices. Each edge node first tries a direct UDP connection to its peers. When that is not possible, a publicly reachable supernode relays the packets. Organisations run their own supernodes and edge nodes, which makes n2n a self-hosted alternative to commercial overlay VPN services for connecting sites and devices.
n2n is developed by ntop, an Italian company that also offers network monitoring products such as ntopng and nProbe. The software is licensed under the GPL-3.0 and its source code is public, so it can be audited and run without a vendor service. Because traffic flows through infrastructure the organisation runs, it stays within environments under its own control. The project publishes no data processing agreement, since it is software without a vendor service.