title: Adding a replica in MongoDB throws an error
body: <p>I'm trying to add a node to a replica set using  <code>rs.add("developer-ViratualBox:30103")</code> and I'm getting the following error message:</p>
  
  <pre><code>{
  "ok" : 0,
  "errmsg" : "Quorum check failed because not enough voting nodes responded; required 2 but only the following 1 voting nodes responded: developer-VirtualBox:30101; the following nodes did not respond affirmatively: developer-ViratualBox:30103 failed with Failed attempt to connect to developer-ViratualBox:30103; couldn't initialize connection to host developer-ViratualBox, address is invalid",
  "code" : 74
  }
  </code></pre>
  
  <p>The node is already running and I'm connected to it using <code>mongo</code> shell. What could possibly be the problem?</p>