Hello all, this is my first post and I am a new member. This is not a tutorial, but more of a sligshot post to help you make the right google searches to start cracking a WPA2 network without a wordlist.
The tool is called Reaver and to the best of my knowledge, it brute forces an extraction of the WPS pin on WPS enabled routers by constantly trying new combinations. During the process, the router will of course lock up, thus it takes a long time, but is still more effective than using a wordlist. You have to install it on a Linux distro and need an external usb antennae to the get the best results.
My two cents