Content filtering can do some of the same tasks as the Citrix NetScaler Application Firewall, and is a less CPU-intensive tool. It is limited, however, to examining the header portion of the HTTP request or response and to performing a few simple actions on connections that match. If you have a complex Web site that makes extensive use of scripts and accesses back-end databases, the Application Firewall may be the better tool for protecting that Web site
Prevent users from accessing certain parts of your Web sites unless they are connecting from authorized locations.
Prevent inappropriate HTTP headers from being sent to your Web server, possibly breaching security.
Redirect specified requests to a different server or service.