Arduino Ethernet Shield MAC

Projects Networking, Protocols, and Devices
1

My ethernet shield has no sticker on the back but work ok with networking sketches.

Q1) Are all Arduino Shields manufactured with a MAC of DE AD BE EF FE ED. I thought that the chip manufacturer had a different MAC for every chip produced.
Q2) Is there a sketch to read back a shield's MAC?

Thanks in anticipation

2

Currently I have an Etherten and three ethernet shields. None have the MAC address on the back. As I understand it, all a MAC address needs is to look like below and be different from any other MAC on your LAN

byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

I don't think I made that up, I think I lifted it from some guy in Florida

This is really more than you need to know

http://www.freetronics.com/pages/setting-arduino-ethernet-mac-address#.UuXRrPt9K9I

I think the only time you need to get serious is when you have multiple Arduinos on the same LAN and changing one digit fixes that.

3

Thanks Nick that Freetronics.com is an excellent link.
Happy Aussie day for yesterday