How do I make Minecraft LAN games show up over WiFi?
Solution 1:
If you have an 'unused' PC sitting around somewhere (doesn't everyone?) you could turn it into a Minecraft Server on your local network. Alternatively if you have a 'beefy' (lots of ram and a speedy processor) PC which is being used (and it on during the times your sons want to play) you could do the same.
Generally you would give the 'Server' a name on your network. You then install the server version of Minecraft, launch it to generate a world, and you are good to go. If your kids have a world they already want to use, you have to copy it to the server minecraft folder with the same name as the world. You then modify the server property file to point to that world.
The boys would then be able to connect to the server just like an 'outside' server. If your server was called 'WINSLOW' and the port is 25565 (the default) they would use WINSLOW:2565 in the connection to get to it. You may have to do some wizardry with your router/firewall but that would depend upon what you have set up on your network.
There are a variety of programs you can use to administer the server.
There are many tutorials on setting up a server available via a Google search. Here is one.