Master sever questions.

How would I set it up?

Does using this:

ACtuly work?

And how would I make servers hook up to master server, anddoes this make it easier for others to be able to connect, especialy outside networks?

Yes it does work, better than the master server offered by Unity to test a new game.

Personally I followed this tutorial to set it up. To use it, you can use the same methods detailed in the documentation.