If you just need a very long virtual ethernet cable between two machines, it's hard to find a solution that's easier than WireGuard. No messing about with CAs

If you just need a very long virtual ethernet cable between two machines, it's hard to find a solution that's easier than WireGuard. No messing about with CAs like with OpenVPN. Start with wg-quick for most setups, and take comfort in knowing that you can easily just shoving the necessary `ip [link|addr]` commands into a custom shell script if necessary.