Hamachi is required. The Hoster's ipv4 addres is the ip for the server. Launch a map where you want to play with your friends, press esc and then press host server.
what is hamachi
no idea, but there is a host button that you can press to open a lan game, if else there is a server file right
is an app that allows you to host games and play them in online multiplayer even if the game just jave local multiplayer. its like you are the server.