title: Rails 4.2 Server port forwarding on Vagrant does not work
body: <p>I have a Vagrant VM with Rails installed with a sample app. The VM is configured to forward the port 3000 (of Rails Webrick server) to my host 3000 port. </p>
  
  <pre><code>config.vm.network "forwarded_port", guest: 3000, host: 3000
  </code></pre>
  
  <p>Everything is configured as seen in a lot of examples.</p>
  
  <p>But, when I try to access <code>http://localhost:3000</code> nothing happens. I've also tried to forward to other random ports like 8081, 25600, without success. Doing a curl request also does not get anything (just a <em>Connection reset by the peer</em> message), and a curl request inside VM works perfectly (as expected).</p>
  
  <p>Both my PC and my VM runs Ubuntu 12.04. I'm using Ruby 2.2.0 and Rails 4.2.0.</p>
  
  <p>An important point is that Apache works normally. I forwarded the port 80 to port 8080 and everything works. It seems that the problem is just with the Rails server, even if when I use other ports (<code>rails server -p 4000</code>, for example)</p>