Can you please provide an example in irules where I reference the HTTP_REFERRER to block access from certain sites?

Hi Carpenteiro, HTTP referer is not an EVENT in iRule language, because it is an HTTP Header in HTTP Protocol. when we write HTTP_XYZ in iRule, it is the name of an event 😉

So, taking in account it is an Header, then what you are looking for is mostly something like the following:

when HTTP_REQUEST {
     if {[HTTP::header "Referer"] starts_with "http://myprivate_site.intra"} {
            you can forward the trafic to the final destination, or load balance it with the command "pool" XYZ_Pool
           forward
}
     else {
           reject
           you can also send an HTTP Redirect if you want.
}