title: python manage.py runserver not work
body: <p>I am trying to learn django on my mac by following along with <a href="https://docs.djangoproject.com/en/dev/intro/tutorial01/#the-development-server" rel="nofollow">Writing your first Django app</a></p>
  
  <p>I run</p>
  
  <pre><code>django-admin.py startproject mysite
  </code></pre>
  
  <p>and it creates the files it should. Then I try to start the server by running</p>
  
  <pre><code>python manage.py runserver 8080
  </code></pre>
  
  <p>It's OK,the message is :</p>
  
  <blockquote>
    <p>Validating models...</p>
    
    <p>0 errors found Django version 1.4.2, using settings 'mysite.settings'
    Development server is running at http:// 127.0.0.1:8080/ Quit the
    server with CONTROL-C.</p>
  </blockquote>
  
  <p>But I when I visit the 127.0.0.1:8080, I get a 504 error page:</p>
  
  <blockquote>
    <p>This Page Cannot Be Displayed</p>
    
    <p>The system cannot communicate with the external server ( 127.0.0.1 ).
    The Internet server may be busy, may be permanently down, or may be
    unreachable because of network problems. ......</p>
  </blockquote>
  
  <p>What am I missing here?</p>