Quite simply, a proxy server is a device that forwards requests from one device to the intended recipient, and does the reverse for any response. Let's talk through Figure 14.7, where we can see this operation:
Figure 14.7: Communicating via a proxy server
- PC A wants to look at the website www.packtpub.com and sends its request to the proxy server.
- The proxy server forwards the request on to www.packtpub.com.
- The web server at www.packtpub.com receives the request and sends the requested web pages to the proxy server.
- The proxy server forwards the web pages to PC A.
It should be noted that between step 3 and step 4, the proxy server may cache the requested web pages locally for use by other devices. Figure 14.8 continues on the preceding steps to show this:
Figure 14.8: Retrieving web pages from a proxy server cache
- PC B wants to look at the website www...