My friends and I don't want play on a dedicated server, we want to play without other people. But we can't properly configure the game - if someone creates a LAN-server, the others can't see it. However, other games work fine via Hamachi, and pings between our PCs are OK.
You don't need hamachi, just download hyperlobby (where almost all the people host their games) register an account and host a game, if you put a password only your friends could join.
It's important to open the port 21000, besides that there is no problem.
If you need further information just ask
This is most likely a problem with the firewall with the person creating the lan game.
Check which ports are used by the game when creating a lan server and open them or whitelist the game application (or both).
Quick and dirty solution would be to turn off your local firewall (NOT recommended). Be sure you are able to trust everyone who might gain access to your local or hamachi network when you do this.