Flutter/Dart: Scan local network to get IP and hostname of connected devices

Question

I'm working on a mobile app using Flutter and want to scan the local network for connected devices. I found the ping_discover_network package, which is working fine, but only gets me the IP address, but I also want to show the hostname of the device.

I tried the reverse() method of the InternetAddress class from the dart:io package, but this only gets me the IP address back. Example:

InternetAddress(ip).reverse().then((value) => print(value));

Is there another package or something I can use, to scan the local network of the app and get the IP address and the hostname back?

Answer 1

OK, I got it working and want to share my solution.

I used the network_info_plus package and the dart:io package.

import 'dart:io';
import 'package:network_info_plus/network_info_plus.dart';
Future<void> scanNetwork() async {
  await (NetworkInfo().getWifiIP()).then(
    (ip) async {
      final String subnet = ip!.substring(0, ip.lastIndexOf('.'));
      const port = 22;
      for (var i = 0; i < 256; i++) {
        String ip = '$subnet.$i';
        await Socket.connect(ip, port, timeout: Duration(milliseconds: 50))
          .then((socket) async {
            await InternetAddress(socket.address.address)
              .reverse()
              .then((value) {
                print(value.host);
                print(socket.address.address);
              }).catchError((error) {
                print(socket.address.address);
                print('Error: $error');
              });
            socket.destroy();
          }).catchError((error) => null);
      }
    },
  );
  print('Done');
}

I'm "scanning" the local network by trying to connect to a given ip and port. If that works, I found a device, I'm looking for. In that cause I also try to get the hostname by using the "reverse()" method.

I have tested it on several iOS and Android devices and it works fine with no errors, so I think its a proper solution.

Answer 2

This does not work on the desktop as I think it is not implemented. Only for iOS and Android.