I am having a problem Running a network service when my app connects to a WiFi network. I am getting a the following exception,

java.net.SocketException: socket failed: ENONET (Machine is not on the network) in the openPort() method bellow

BroadcastReceiver

@Override
public void onReceive(Context context, Intent intent) {

    String action = intent.getAction();

    if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(action)) {

        NetworkInfo networkInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);

        if (networkInfo.getState() == NetworkInfo.State.CONNECTED) {
            welcomeService = new BroadcastService(context, "Welcome");
            Log.i(TAG, "onReceive: SUPPLICANT-STATE ---> Connected");
            //do something
            if (!serviceRegistered) {
                welcomeService.registerService();
                serviceRegistered = true;
            }
        }

        if (networkInfo.getState() == NetworkInfo.State.DISCONNECTED) {
            Log.i(TAG, "onReceive: SUPPLICANT-STATE ---> Disconnected");
            //do something
            unRegisterService();
        }
    }

}

public void unRegisterService() {
    if (serviceRegistered && welcomeService != null) {
        welcomeService.unregisterService();
        serviceRegistered = false;

    }
}

BroadcastService

public void registerService() {
    NsdServiceInfo serviceInfo  = new NsdServiceInfo();
    serviceInfo.setServiceName(mServiceName);
    serviceInfo.setServiceType("_http._tcp.");
    serviceInfo.setPort(openPort());

    mNsdManager = (NsdManager) mContext.getSystemService(Context.NSD_SERVICE);

    mNsdManager.registerService(serviceInfo, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
}

private int openPort() {
    try{
        // Line that throws the exception
        return  new ServerSocket(0).getLocalPort();
    }catch (IOException ioe){
        Crashlytics.logException(ioe);
        ioe.printStackTrace();
        return 0;
    }
}

This the Broadcast Receiver only runs on when the main activity is showing. and it works fine on the first run but when I change the WiFi network this happens. Help world be greatly appreciated.