title: asp.net and IIS caching issue
body: <p>I have put my web site through Google's pagespeed test and it has told me to "Leverage browser caching".</p>
  
  <p>I did some research into this and found that I need to enable the content expiration in IIS 6. I did this and set the content to expire every 30 days. I then put my web site through the pagespeed test again and it still came up with the "Leverage browser caching" recommendation.</p>
  
  <p>I have also put the web site through <a href="http://web-sniffer.net" rel="nofollow">http://web-sniffer.net</a> to see whats coming back and it comes back with Cache-Control: private.</p>
  
  <p>I then tried <code>&lt;%@ OutputCache Duration="30" VaryByParam="none" %&gt;</code> in the web form and now it's coming back with Cache-Control: public, max-age=30 which I guess is along the right lines but the google page speed test is still coming back with a list of resources (mostly images) on my web page that have no expiration.</p>
  
  <p>I'm quite confused on this subject. I was under the impression that the web site would inherit from the IIS settings but this wasn't the case until I turned on the outputcache on the page. Is there a way I can get the web site to use the IIS settings or has it got to be done on a page-by-page basis?</p>