All devices are in the same Ethernet segment. They are connected to a standard consumer router. They all were assigned to IP addresses in a range of 10.0.1.0 - 10.0.1.20. The goal is to identify devices in the same network, even if the IP has changed and to protocol when a device is online.
I was researching on this problem for weeks and I have not found anything useful on the Internet. This is the only piece of code I have found so far: http://mbed.org/users/va009039/code/w5200NetIf/file/a8df39b4f3aa/MyNetUdpSocket.cpp, line 124
W5100.readSnDHAR(_socket, mac) but it does not work.
Is it even possible to get a MAC address for a found device (IP is known then) in the same network?