Pool member FQDN on server side, Virtual server name on client side web browser

Hi,

In your iRule you have to use HTTP_RESPONSE event to match traffic coming from your webserver.

Your iRule will be like that :

when HTTP_REQUEST {
    if { [string tolower [HTTP::host]] equals "vserver.domain.com"} {
        HTTP::header replace Host "poolmem1.domain.com"
    }
}
when HTTP_RESPONSE {
    if { [string tolower [HTTP::host]] equals "poolmem1.domain.com"} {
        HTTP::header replace Host "vserver.domain.com"
    }
}