n2n is a peer-to-peer VPN that makes it easy to create virtual networks that bypass intermediate firewalls.
n2n solves the problem of connecting machines across restrictive network boundaries by establishing direct peer-to-peer UDP connections between edge nodes whenever possible. The architecture relies on a supernode that acts as a discovery and relay service, allowing edge nodes to announce themselves and discover other nodes within a named community. When direct peer-to-peer connections cannot be established due to NAT or firewall constraints, the supernode relays traffic between nodes. Multiple communities can share a single supernode, and individual machines can participate in multiple communities simultaneously. Payload encryption is supported to protect traffic between edge nodes, with configurable cipher options including AES as the default.
Adoption suits scenarios where you need to create virtual networks across firewalls with minimal infrastructure overhead. The tool is lightweight and straightforward to deploy: edge nodes can connect to public supernodes immediately, or you can run your own supernode on a VPS by opening a single port. The project recommends using custom community names and encryption keys for security, and suggests running a private supernode to improve privacy and reduce load on public infrastructure. The stable release branch is recommended for production use, though the development branch offers newer features at the cost of potential compatibility breaks.
The project maintains a substantial base of real-world adopters, as evidenced by the fact that almost all open issues are raised by outside users rather than the core team. Maintainers typically respond to new issues and pull requests within a day. Work in the issue tracker is dominated by user questions and enhancement requests.
