Getting the IP address of the current machine using Java

I am trying to develop a system where there are different nodes that are run on different system or on different ports on the same system.

Now all the nodes create a Socket with a target IP as the IP of a special node known as a bootstrapping node. The nodes then create their own ServerSocket and start listening for connections.

The bootstrapping node maintains a list of Nodes and returns them on being queried.

Now what I need is the node must register its IP to the bootstrapping node. I tried using cli.getInetAddress() once the client connects to the ServerSocket of bootstrapping node but that didn’t work.

1. I need the client to register its PPP IP if available;
2. Otherwise the LAN IP if available;
3. Otherwise it must register 127.0.0.1 assuming its the same computer.

Using the code:

System.out.println(Inet4Address.getLocalHost().getHostAddress());

or

System.out.println(InetAddress.getLocalHost().getHostAddress());

My PPP Connection IP address is: 117.204.44.192 but the above returns me 192.168.1.2

EDIT

I am using the following code:

Enumeration e = NetworkInterface.getNetworkInterfaces();
while(e.hasMoreElements())
{
    NetworkInterface n = (NetworkInterface) e.nextElement();
    Enumeration ee = n.getInetAddresses();
    while (ee.hasMoreElements())
    {
        InetAddress i = (InetAddress) ee.nextElement();
        System.out.println(i.getHostAddress());
    }
}

I am able to get all the IP addresses associated all NetworkInterfaces, but how do I distinguish them? This is the output I am getting:

127.0.0.1
192.168.1.2
192.168.56.1
117.204.44.19