NetworkInterface doesn't return all mac addresses

Question

In part of our code i am trying to bind a mac address with our license file and i am facing an issue that my code for figuring out all the mac addresses of the machine is not returning all the physical mac addresses. Here is the code to get all the mac addresses

public static Collection<String> getAllLocalMacAddresses() throws IOException {
    final Enumeration<NetworkInterface> inetAddresses = NetworkInterface.getNetworkInterfaces();
    final Collection<String> addresses = new LinkedList<String>();

    while(inetAddresses.hasMoreElements()){
        final byte[] macBytes = inetAddresses.nextElement().getHardwareAddress();

        if(macBytes == null)
            continue;

        addresses.add(getMacAddress(macBytes));
    }

    return addresses;
}

static String getMacAddress(byte[] macBytes){
    final StringBuilder strBuilder = new StringBuilder();

    for (int i = 0; i < macBytes.length; i++){
        strBuilder.append(String.format("%02X%s", macBytes[i],
                (i < macBytes.length - 1) ? ":" : ""));
    }

    return strBuilder.toString().toUpperCase();
}

Here is the result that i get from this method

[, 00:00:00:00:00:00:00:E0, 00:26:B9:30:6D:CB, 00:26:B9:30:6D:CB, 00:00:00:00:00:00:00:E0, 00:26:B9:30:6D:CB, 02:26:B9:30:6D:C1, 00:26:B9:30:6D:CB, 00:00:00:00:00:00:00:E0]

The output from "ipconfig /all" shows me these physical addresses (i could paste the out put for this command if required)

00-26-B9-30-6D-C3
02-26-B9-30-6D-C1
00-26-B9-30-6D-C5
00-26-B9-30-6D-C9
00-26-B9-30-6D-CB
00-00-00-00-00-00-00-E0

Now if you see the java code did not return the address "00-26-B9-30-6D-C3" and also printed the address "00:26:B9:30:6D:CB" thrice. Any idea why this would be happening and how can i fix it.

Any help will be deeply appreciated :)

Answer 1

Try http://docs.oracle.com/javase/6/docs/api/java/net/NetworkInterface.html#getSubInterfaces() - it could be a virtual interface