title: Express.js- Why is Localhost '::'
body: <p>Can anyone tell me why my server address (host) is :: and not localhost</p>
  
  <pre><code>var express = require('express');
  var app = express();
  
  // respond with "hello world" when a GET request is made to the homepage
  app.get('/', function(req, res) {
    res.send('hello world');
  });
  
  var server = app.listen(3000, function () {
    var host = server.address().address;
    var port = server.address().port;
    console.log('Example app listening at http://%s:%s', host, port);
  });
  </code></pre>
  
  <p>This returns</p>
  
  <pre><code>Example app listening at http://:::3000
  </code></pre>
  
  <p>It works fine when I go to <a href="http://localhost:3000/" rel="noreferrer">http://localhost:3000/</a></p>