title: IE 11 doesn't show favicon when accessing the sever through ipv6 address
body: <p>I used express as my local server to test my web application. Everything 
  was OK when i accessed the server using ipv4 address(localhost:8000) in IE 11 browser. However, when i accessed the server using ipv6 address([::1]:8000), everything worked well except IE didn't show favicon.   </p>
  
  <p>I checked the log information in debug mode in IE and found that IE didn't send request to require the favicon(confirm in express console that server didn't receive the request of requiring the favicon).   </p>
  
  <p>PS:I tried to access the icon directly using <a href="http://[::1]:8000/favicon.ico" rel="nofollow">http://[::1]:8000/favicon.ico</a>. It was OK.</p>