The Reverse Proxy

The reverse proxy, sometimes referred to as the inbound proxy is the proxy deployed at the edge of your network to protect the organization's web presence. Reverse proxies that double as web caches are also used to expand the capacity of the organization's web servers. Typically a web cache can handle many more requests for content than a typical web server. Reverse proxies can also protect web servers from attacks coming from the Internet.

In addition to an organization's web presence, a reverse proxy can also help secure services the organization serves to their employees through the web, such as Outlook Web Access (OWA), Micrsoft Exchange's web based email offering. Typically organizations allow their employees to retrieve email using this web service when they are traveling or working from home. A reverse proxy can help prevent malicious attacks, denial of service attacks, and other security risks to the web server.

A reverse proxy protecting an OWA server has to be able to intercept SSL, as most organizations will want to make sure that email access is secure. A good reverse proxy will be able to force users to do an SSL login (redirect to https), logout inactive users. A truly advanced proxy will also provide virus protection and content filtering capability, including ILP and DLP (Information and Data Leakage Protection).