Is it possible in the Minecraft Bedrock Edition to ban a player based on his Mac address? Unfortunately, it is very easy to bypass an IP ban.
Unfortunately, this is not possible without a "client-side modification". As already mentioned, plugins in this direction require a CSM.
The Mac address can also be changed quite easily, so that doesn't help.
No do not go.
But because Minecraft bans UUID rather than name, that shouldn't be a problem.
You can enter a name for the / ban command, but the server then checks which UUID it has on Mojang's servers and then enters the UUID in the banned_players file.
So with Minecraft there are / ban and / ipbann but if I do ipbann it can still be used with a VPN or not?
If you use the / ban-ip command, only the IP with which the person has currently connected will be blocked.
Often you get a new IP address after restarting the router.
"Earlier" when the command was added, the IP assignment was not yet so acute. There were still "sufficient" addresses. But that is no longer the case.
The best thing you can do is / ban because it bans the UUID.
And if your server is running with online-mode = true, that's no problem.