In this web content, the author explains how Tailscale overcomes NATs (Network Address Translators) to establish peer-to-peer connections between devices. The author highlights that the techniques used are applicable to many protocols, such as WebRTC. The article discusses the importance of using UDP as the base protocol for NAT traversal and the need for direct control over the network socket. The author describes how stateful firewalls pose a challenge and explains the process of traversing firewalls. The content also covers the role of NAT devices and the use of STUN (Session Traversal Utilities for NAT) for address discovery. Overall, the article provides insights into the technical aspects of NAT traversal and highlights the importance of coordination and communication between devices.
https://tailscale.com/blog/how-nat-traversal-works/