This sketch uses the DHCP extensions to the Ethernet library to get an IP address via DHCP and print the address obtained using an Arduino Ethernet shield.
Step 2: Build Your Circuit.
The Ethernet shield allows you to connect a WizNet Ethernet controller to the Arduino boards via the SPI bus. It uses pins 10, 11, 12, and 13 for the SPI connection to the WizNet. Later models of the Ethernet shield also have an SD Card on board. Digital pin 4 is used to control the slave select pin on the SD card.
Source : https://myrobotduino.blogspot.kr/2016/08/dhcp-address-printer.html
Author : Robot edu