title: Heroku Get IP Addresses
body: <p>Just starting out with Heroku and I'm trying to deploy someone elses node application on there. To start up the server I go into <code>node server.js</code> and that works. It then shows <code>relevant IPs { '[MY IP ADDRESS]': null }</code></p>
  
  <p>I deployed to Heroku, and the server is working, but it brings up <code>relevant IPs { dummy: null }</code>. I searched through the code to find what <code>dummy</code> meant. Here is what I found:</p>
  
  <pre><code>// find all ip addresses
  // We use a dummy for a special case where node can't list network interfaces (freeBSD)
  
  var sockets = {'dummy': null};
  for (var name in interfaces) {
  console.log('discovering all IPs from', name);
  interfaces[name].forEach(function (ipInfo) {
    if (ipInfo.internal == false &amp;&amp; ipInfo.family == "IPv4") {
      // this one is interesting, use it
      delete sockets['dummy'];
      sockets[ipInfo.address] = null;
    }
  });
  }
  
  console.log("relevant IPs", sockets);
  </code></pre>
  
  <p>So, my question is, can Heroku find an IP address, and if yes, why is it bringing up <code>dummy</code>?</p>