Ionic 2 App and server on localhost communication not working

Hey everyone,

I´m building a Ionic 2 App for windows 10 that needs to communicate with a server running on localhost.

All works good if I run my application in a browser (either with ionic serve or ionic run browser) but the communication between App and LocalServer is not working if I launch the application with ionic run windows and I´m unable to get any error message (the rest of the App works fine).

In a scenario where the server runs on another device (not using localhost) all works good again… The issue is that I need to have the App and the server running on the same device, any tip on what is hapening and how this can be solved?


var io = require('')();
io.on('connection', function(client){
  client.on('message', function(data){
    console.log('message: ' + data);
  client.on('disconnect', function() { console.log('Disconnected...'); });

Client methods (Ionic 2 App):

  connect() {
    this.socket = io.connect('');
  disconnect() {
  send() {
    this.socket.emit('message', 'test message...');

What happened if you replace the ip address by the ip address of the server?

1 Like

The behavior is exactly the same… As soon as the server is running in the same device then the Ionic App (in this case a Universal Windows App) the communication does not work. Either using, localhost or 192.168.x.x addresses…

Another strange behavior that might help describing the problem:

if I launch the server and the application and call the connect method (from the client) nothing happens in the server… but just by restarting the server I´m able to see the result of the console.log('Connected...');. Since the client is configured to automatically reconnect after a connection is lost, the console.log('Connected...'); is probably executed due to this re-connection request.

This means that, in some way, the Ionic App client is able to reach the server, although I´m not able to figure out why this just happens after restarting the server. Even after that I´m not able to have real time communication, the problem is the same, I´m only able to get some activity in the server upon restarting it.