This is part of the Semicolon&Sons Code Diary - consisting of lessons learned on the job. You're in the networking category.
Last Updated: 2024-04-25
Join two trusted networks (each of one or more machines) across an untrusted intermediate network - as if hooking them up with a secure secret cable.
Merely that these machines are communicating and may form part of a VPN. Therefore an outsider might understand that there are trust relationships, but have no actual info about the traffic itself. Even the type of transport protocol (UDP/TCP/other) is hidden form prying eyes.