如何在考虑各种IP的网络中发现主机？

Question

我正在开发一个Android应用程序，我必须实现一个功能，发现我所连接的网络的所有主机（例如WiFi）。

我实现了一个有效的功能，这是我的代码：

public class ScanNetwork {

    private static final int NB_THREADS = 10;
    private ArrayList < String > hosts;

    public ArrayList < String > ScanNetwork(String ipAddress) {

        hosts = new ArrayList <> ();
        String subnet = ipAddress.substring(0, ipAddress.lastIndexOf("."));

        ExecutorService executor = Executors.newFixedThreadPool(NB_THREADS);
        for (int dest = 0; dest < 255; dest++) {
            String host = subnet + "." + dest;
            executor.execute(pingRunnable(host));
        }

        executor.shutdown();
        try {
            executor.awaitTermination(60 * 1000, TimeUnit.MILLISECONDS);
        } catch (InterruptedException ignored) {}

        return hosts;
    }

    private Runnable pingRunnable(final String host) {
        return new Runnable() {
            public void run() {

                try {
                    InetAddress inet = InetAddress.getByName(host);
                    boolean reachable = inet.isReachable(1000);

                    if (reachable) {
                        hosts.add(host);
                    }
                } catch (UnknownHostException e) {
                    System.out.println("Log: " + e);
                } catch (IOException e) {
                    System.out.println("Log: " + e);
                }
            }
        };
    }
}

此代码适用于某类IP，例如192.168.1.10，但不适用于10.1.25.1。

问题很简单，如何在考虑各种IP的情况下实现发现某个网络中所有主机的功能？