> Thanks once again for sharing light on this. Do you have any examples > where I can use req_header to detect if my clients have their own proxy > servers? > > Any clue, web links or posts will highly be appreciated. > > Also is req_header the only option whereby we can detect child proxies? > Or do we also have other options for detecting child proxies? > > I googled and found the Follow X-Forwarded-For headers (follow_xff) tag. > Do you have any ideas regarding this? Yes, X-Forwarded-For headers can be useful. There is same problem as with Via header - spoofable. In default squid configuration is directive forwarded_for set to on. It means, that squid forward forwarded-for header to upstrem proxy. Your squid has to be compilled with --enable-follow-x-forwarded-for option, and in squid config you need this directives: follow_x_forwarded_for allow all acl_uses_indirect_ckient on log_uses_indirect_client on Then you can track clients behind child proxy's. But all is depending on child squid configuration.
