Is this a corporate or home router? I've never worked with a Brocade router before; is there a serial port for you to connect a rollover cable? If there is no default IP set up on it, I'm not sure how you are going to connect to it. Is your computer pulling an IP?
To fully answer your question, the typical way to find out what your gateway's IP is (to be able to connect to it) is to open up command prompt** and type in "ipconfig".. your computer should have its own ipv4 address and it should also list the gateway. Image: http://imageshack.us/a/img88/9913/ipinfot.png
**To open command prompt, start -> type in CMD in the search bar and hit enter
This post was edited on 10/10 at 9:03 pm