Many districts use proxy servers in their network environments. A proxy server sits between client applications, such as a web browser, and a real server. They forward requests from internal nodes to the Internet. Proxy servers can use the these functions to control related actions:
For an application to access the Internet in a proxy server environment, the application must know the hostname and port number of the proxy server. The application sends all requests for network services to the proxy server for processing. The proxy server receives the requests and determines what to do with them. If a district implements all functions above, the proxy server verifies that:
If the request passes all verifications above, the proxy server stores a record of the request and issues its own request for the same object to the Internet. When the reply returns to the proxy server, the server matches the reply to the original request stored and forwards the reply to the original requestor. |