strange mongodb behavior when connecting to invalid host/port combination

I use node.js, mongodb, mongoose 2.3 for my app.

I have following code:

  console.log(config);
  db = mongoose.connect(
    config[MONGO_HOST_CONFIG],
    config[MONGO_ACCOUNTS_DB_CONFIG],
    config[MONGO_PORT_CONFIG],
    function(err) {
      if (err) throw err;
    }
  );

Config looks like:

{ 'mongo.host': 'google.com',
  'mongo.port': '27',
  'mongo.accounts.db': 'accounts',
  'mongo.sessions.db': 'sessions' }

It times out after some time. Question: How do I find out the timeout interval?

If I change HOST to: example.com: It fails immediately which is good.

If I change host to aruunt.com, it never times out and goes into wait state. The connection is also not established. aruunt.com is some random domain owned by me.

What is the issue here?