Im on an OS X 10.4 Mac server running bind 9.3, I just replaced the entire network with cisco hardware, all machines including servers now have private ip addresses that t he firewall resolves. I need to have a dns that works for both internal and external connections. any help would be great!

Without more information it's hard to know where to start. Sounds like you should start by describing the firewall, what model, how you configured it, etc.