Warcraft 3 and how to host a game with 2 computers connected to a wireless router?

My cousin brings his computer over and hooks up to my router so we can play games. We can't host a game on either computer. How do we set it up so we can host and play in the same game???

Make sure you both have the latest patch for it, both have different keys for each game. And fire walls are down. You need to be sharing the network.

Make sure both the computers are connected to the router.Also check the warcraft versions.If they are different you cant play multiplayer.You have to get the warcraft version switcher.Otherwise you can directly go to local area network and play without usin any software.