I want to be able to connect to a mysql database remotely but don't know what ipaddress I would be connecting from. Either I'll be connecting over a vpn with dynamically assigned ip addresses or I'll be connecting from inside the company network.
So to allow access from any IP address use user_name@'%.%.%.%'
If you haven't enabled networking to mysql you'll need to do that first: http://www.cyberciti.biz/tips/how-do-i-enable-remote-access-to-mysql-database-server.html
Of note (if looking at the previous link) after at least mysql server version 5.1.54 for compatibility there is no