I used ZeroTier (free) to allow my brother’s friends to connect to his Minecraft server (instead of port forwarding on the router due to CGNAT on our home inter

I used ZeroTier (free) to allow my brother’s friends to connect to his Minecraft server (instead of port forwarding on the router due to CGNAT on our home internet). Based on my experience, I give it 5/5. The client software is under “Business Source License” allowing you see what runs on your machine (unlike other options). It defaults to being dependent on a closed-source proprietary backend coordination server, to orchestrate the P2P connections. It was easy to setup the virtual network, and it was very easy to get members to join. There’s a packet filter language that operates on every node in the network, so you can lock down traffic really well, down to a single protocol & port (e.g.: Minecraft). The UX is elegant and non-intrusive, thought the network configuration interface isn’t the best for non-techy users. The networking performance for our Minecraft usage was excellent. The stability, even during poor underlying connection times, was impressive. Each node in the network is assigned an IP in a private use area (like 192.168.123.123, but you can choose the ranges yourself), allowing other software to use the virtual network effortlessly. No routing shenanigans are applied to your existing network interfaces. I hope this product stays awesome (and as secure as it currently seems). I would be happy to migrate my own professional virtual network needs and pay for a premium service if I knew for sure the coordination/orchestration server wouldn’t disappear within the next 10 years, rendering the service dead. Will definitely use for temporary free stuff, though. (Tragedy of the commons, oops!)