I too have a Brother printer and setting it up was soo easy.Save your self a lot of headaches and give the printer a "static IP Address" something that is in the same octet of your network, but out of range of the rest of the stuff on your network. Most internal networks are 192.168.1.xxx (the xxx are the octets and it goes from 001 to 256) The router assigns address lowest to highest in order of connection. Wireless devices get an address too. Get the IP address of your mac, for example mine is 192.168.1.145, and set the IP address of the printer to the upper range of the last 3 numbers up to 255 (you can't use 256, there are a few other address which are not allowed, but they elude me at the moment)
I gave the Brother printer a static address of 192.168.1.252. I set it on the front panel of the printer, not the simplest exercise, but not brain surgery either. When I enter the static ip address in a web browser (like Safari or Firefox ) I go the the home page of the printers built on web server. There you can check your toner and print drum life, and make all kinds of settings.
If you know the IP address of your router you can get into it the same way and poke around, and make some changes like passwords.