Solder 4 Red/Green LED's to a project board.
Run ~300Ohm resistor to ground pin on all 4 LED's. (Center pin is common on these LED's)
Wire Green side to PIN 2,3,4,5 of UNO
Wire Red side to PIN 6,7,8,9 of UNO
Ground resistors.

Solder the +V pin from the Green LED on the RJ45 Ethernet connector.
Connect this to A0 on the UNO
Yes - there IS possibly a way to do this in software, but I am a hardware hacker and this works great!

Download the UIPEthernet Library: https://github.com/ntruchsess/arduino_uip
Edit the timeout on DHCP to something more reasonable than 60 seconds.
Download the code - I'm using Arduino IDE 1.6.5 here.