How to restrict access to a URL from a different URL

You are heading in the right direction. Your iRule just checks if there is a Referer header. If you want to restrict from a single site, you'll have to check agains the value of the Referer header.

 when HTTP_REQUEST { 
   if { ([HTTP::header "Referer"] ne "www.birdwatch.com") } { 
     HTTP::respond 200 Content "SORRY, You Can't access this page directly"; 
   } 
 }

This assumes you have the "seagulls_pool" set as the default pool for the virtual. If not, then add an "else" to the if clause and do the pool assignment there.

-Joe