HiLetgoW5100 Ethernet Network Shield W5100 Ethernet Expansion Board with SD Card Slot for Arduino UNO MEGA2560

works as advertised but you might want a W5500 instead

Works just fine so far.***WARNING***Make sure that the I/O pins set inside completely. You have to put some pretty firm pressure on it.I was debugging for hours trying to figure out why it wasnt working but it was just because the pins were sitting in all the way....Hope this helps

I feel compelled to write this so others can have the info, as there's surprisingly little information out there about Ethernet shields. I used the "Web client" sketch in the ethernet tab in the examples menu in the IDE. It's created 18 Dec 2009, by David A. Mellis, modified 9 Apr 2012 by Tom Igoe, based on work by Adrian McEwen. I added no libraries or extras and it worked fine with a Sunfounder Mega board.It does have an issue where the ethernet jack is. When you put it on the board, the solder joints on the bottom touch the shell of the USB connector on the arduino, and short it out. I put a piece of tape over the USB connector and it's fine now. If you have a USB-C board, you wouldn't need to do that. I did have to slightly move the shield up and down to get it to work as the aforementioned solder points keep it from sitting totally level on the arduino. Can't speak as to the microSD slot.

can anyone tell me about the numbers on the Ethernet jack of the shield (14/31) and on the anti-static bag a sticker that said AM 00/00. are either of these part of the MAC address? I have been able to successfully get it on the internet but still know very little about the shield.

It works with the correct library

Appears to work as well the original. I have used both the ethernet features (using the original Arduino ethernet library), as well as the micro SD card slot with great success.

Know what you are buying. These are generic Chinese knock-offs. It's all open source hardware, so it's perfectly legal. If you're OK with the risks, go for it. If not, deal with the handful of reputable suppliers in the Arduino world like Arduino.cc or Adafruit. The genuine Arduino.cc W5001 shield has been discontinued. This one does work with the Arduino.cc ethernet library though. Mine was initially inoperative. It had a big ugly solder bridge from pin 5 of the ICSP header to the shroud of the SD slot. You can see in the picture how close they are. This grounded the /reset pin holding the shield and the attached UNO in reset. This unit could not possibly have been tested in the factory. After removing the solder bridge the unit worked satisfactorily.

Reasonable shipping time; fits properly on my Arduino. Might update when I attempt to turn it on soon.