LinuxTech

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In computer networks, a proxy server is a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server and the proxy server evaluates the request as a way to simplify and control its complexity. Proxies were invented to add structure and encapsulation to distributed systems An advantage of a proxy server is that its cache can serve all users. If one or more Internet sites are frequently requested, these are likely to be in the proxy's cache, which will improve user response time. A proxy can also log its interactions, which can be helpful for troubleshooting. How a simple example of how proxy servers work : When a proxy server receives a request for an Internet resource (such as a Web page), it looks in its local cache of previously pages.

What is Port Forwarding ? Port forwarding, or tunneling, is the behind-the-scenes process of intercepting data traffic headed for a computer's IP/port combination and redirecting it to a different IP and/or port. A program that's running on the destination computer (host) usually causes the redirection, but sometimes it can also be an intermediate hardware component, such as a router, proxy server or firewall. Of course, even though anyone sending data to a server isn't aware of what's going on, the request will still get to its ultimate destination. Playing with packets. It all starts with the packets that get created when you send a data request over the Internet. Normally, a network router will examine the header of an IP packet and send it to a linked and appropriate interface, which in turn sends the data to the destination information that's in the header. But in port forwarding, the intercepting application (or device) reads the packet head