ZeroTier: it connects my laptop, my VDS, and my behind-two-NATs home machine pretty efficiently. That is, e.g., when my laptop is connected to the home wi-fi, the zerotier interface seems to exchange packets directly with the home machine.
Presence of an Android client is important for me. Auto-reconfiguation in a new network (laptop on a public wi-fi, phone on mobile networks) is nice.
"Peer-to-peer discovery" is not important for me, that is, I'm OK with my nodes discovering the network via a control center. (You can self-host the control center.)
Running a VPN between only 4 machines wasn't that useful, and it needs a central server. I quite like Meshbird's idea of using DHT instead. If it ever evolves to improve its crypto and setup, I might take it up instead.
There is a PDF by the original author that explains the difference from "VPNs".
A reachable IP address and a TAP device are the only requirements.
For example, two edges can also be supernodes. A third party supernode would only be needed for the initial connection. Once connected, then each can use the supernode run by the other. The third party is no longer needed. No central server.
As for DHT, who runs the DHT bootstrap server?
Do DHT users run their own bootstrap servers?
Do users exercise any control over the DHT? Who does?
By central server I mean a referral hub, yes. But I just couldn't keep one up reliably (in the sense that I didn't want to, since the mesh had to be fairly dynamic in my case).
