Are you at work or at home when you're doing this ?
If you've configured mySQL with the proper IP address it should work, but there's a few reasons why your IP isn't the IP that the server will see.
Do you have a way of checking what your IP is by the time it gets to the mySQL server ?
An easy way might just be to google "what is my IP" and checking it that way.
Sorry for all the questions, but I think it's a network/environment configuration rather than Tableau doing something wrong.