I'm a relatve newcomer to networking, and I need help with my firewall (the build-in one). I'd like to keep it on all the time, but it prevents certain services when it's running. I know the solution is to open certain ports that those services use while keeping all the rest closed, but I don't know how to find out what ports they're using, and I'm shaky on how to open them. How do I do it? Oh, by the way, I'm running Tiger.