If you have the RT314, then I can help ya 🙂
1. Start > Run
2. Type "telnet ip.of.your.router" (without quotes, default is 192.168.0.1).
3. Enter your password (default is 1234, I think).
4. It should give you a menu with numbers from 1 to 24 (not continuous).
5. Type "24" (without quotes) and press enter.
6. Type "1" (no quotes) and press enter.
7. Should say WANyour:ethernet:mac:address:is:hereyour.assigned.ip.address
Voila.
You can also find it through your web browser by connecting to your router.