Arduino ethernet shield not getting correct IP
The sketch you have written works perfectly with a cheap Ethernet Shield clone from eBay.  Those (and the older Arduino Ethernet Shields) use the Wiznet W5100 chip.

The new shields, of which you have one, use the newer, more powerful, Wiznet W5500 chip.

You can't use the old Ethernet library with the new Wiznet W5500 chip.  It doesn't work.

You have to use the "Ethernet 2" library as described here:


http://labs.arduino.org/Ethernet+2+Library



  Note: this library is used to work with the new Ethernet shield (version 2) and Leonardo Eth that uses a new Controller W5500.


That page is linked from the product page you link to above.  If you had read the product page you would already know this.