Determining MAC address via software

I am looking to deploy a few ethernet connected boards based on Uno that use the w5200 module, which I’m pretty sure comes with a mac address.

Is there a way to find the mac address via software? The reason is that I would like them all to report data along with the mac address so I know where the data is coming from without having to change the program for each board.

My alternative is to add an EPROM or something similar with a unique number on it that would be read and reported each time data is sent.

I ran:

#include <SPI.h>
#include <Ethernet.h>

#if defined(WIZ550io_WITH_MACADDRESS) // Use assigned MAC address of WIZ550io
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED}; // changed last from 0xED

void setup() {
  for (byte i = 0; i < 6; i++) {
    Serial.println(mac[i], HEX);

void loop() {

but it just returns the mac address that is coded into the program. Is there a way to do this, even if I have to change Wiznet modules?