If the proxy server can query neighbor or parent caches to determine whether they have the requested document cached, and then obtain the document from the neighbor or parent, it will prevent the request from being routed to the Internet where connections are sometimes unpredictable. Dynamic proxy routing for automatic content discovery complements distributed caching. In cases where neighbor or parent proxies are outside the administrator's direct control and cannot be included in an array, dynamic querying is an effective means of sharing content. It also preserves network bandwidth by eliminating undesirable traffic. Proxy servers should provide the filtering capabilities described below.
Proxies provide a number of security benefits when used in the most common firewall configurations.
Without such a mechanism, it is possible for users to bypass the proxy and communicate with external hosts directly. Otherwise, an abundance of APIs, applications hooks, and unnecessary services leave too many security holes that can be exploited by malicious individuals. Access Controls A proxy server is a natural place to control internal users' access to the Internet. In some cases administrators would like to restrict individual users from accessing specific sites, so the proxy server should provide granular control over who has access to network resources. URL Filtering Many organizations have concerns about whether employees use the Internet productively.