title: When TCP connections are opened?
body: <p>I wanted to define which version of HTTP is used(in empiric way) by monitoring the number of TCP connections which are opened when the browser requiring some page. I've chosen the page with 2 pictuers and run</p>
  
  <pre><code>netstat -s | grep "active connections"
  </code></pre>
  
  <p>The result was 1613 </p>
  
  <p>Then I've opened this page <a href="http://c2.com/doc/pages.html" rel="nofollow">http://c2.com/doc/pages.html</a> and run this command again:
  The result was 1637.</p>
  
  <p>How is that possible if I closed all the web clients which may send TCP packets, there're only browser and bash opened. Why so many TCP connections were opened?</p>