/** Usually returns MAC address (48 bits = 6 bytes). */ public static byte[] getMacAddress(final InetAddress addr) { if (SystemUtils.getJavaVersion() < 1.6f) { return null; // getHardwareAddress is not supported } final NetworkInterface ni; try { ni = NetworkInterface.getByInetAddress(addr); } catch (SocketException e) { return null; } if (ni != null) { final byte[] mac; try { mac = ni.getHardwareAddress(); } catch (SocketException e) { return null; } return mac; } return null; }