Enterprise is hosting games using the system LocalAreaNetwork, to see their games in your wc3 list you need to make an account on their website and install the Java Runtime Environment. No need cdkey to join their games.
To join their games follow the steps.
1. Make a new account at the ENT forum, Your username must be the same from your Lan username
2. Click in the ENT Connect link
3. Execute the Java Enviroment and wait for the green signal
4. Open Warcraft III and select Local Area Network. There, a list of games should come up.
