code: public static String getEthernetAddress() {
  
          try {
              InetAddress ip = InetAddress.getLocalHost();
              if (!ip.isLoopbackAddress()) {
                  NetworkInterface network = NetworkInterface.getByInetAddress(ip);
                  byte[] mac = network.getHardwareAddress();
                  StringBuilder sb = new StringBuilder();
                  for (int i = 0; i < mac.length; i++) {
                      sb.append(String.format("%02X%s", new Byte(mac[i]), (i < (mac.length - 1)) ? ":" : ""));
                  }
                  return sb.toString();
              }
          } catch (Throwable t) {
              // if an exception occurred return a dummy address
          }
          // return a dummy ethernet address, if the ip is representing the loopback address or in case of exceptions
          return CmsUUID.getDummyEthernetAddress();
      }
docs: Returns the Ethernet-Address of the locale host.<p>
  
  A dummy ethernet address is returned, if the ip is
  representing the loopback address or in case of exceptions.<p>
  
  @return the Ethernet-Address