Ethernet Shield W5100 R3 Support Poe For Arduino Uno Mega 2560 Nano
Note that because the W5100 and SD card share the SPI bus, only one can be active at a time. If you are using both peripherals in your program, this should be taken care of by the corresponding libraries. If you're not using one of the peripherals in your program, however, you'll need to explicitly deselect it. To do this with the SD card, set pin 4 as an output and write a high to it.
Ethernet Shield W5100 R3 Support PoE For Arduino UNO Mega 2560 NanoDescription:The Ethernet Shield for Arduino connects your Arduino to the internet in mere minutes. Just plug this module onto your Arduino board, connect it to your network with an RJ45 cable(not included) and follow a few simple instructions to start controlling your world through the internet.