Most often they are used for the following purposes:
Providing access from computers on the local network to the Internet;
Data caching: if calls to the same external resources often occur, you can keep a copy of them on the server and issue them on request, thereby reducing the load on the channel to the external network and speeding up the client receiving the requested information;
Data compression: the server downloads information from the Internet and transfers the information to the end user in a compressed form. Such proxy servers are mainly used to save external traffic;
Protection of the local network from external access: for example, you can configure the server so that local computers will access external resources only through it, and external computers will not be able to access local resources at all (they only see such a server);
Restricting access from a local network to an external one: for example, you can restrict access to certain websites (which, in fact, we are doing, malicious administrators :)), restrict the use of the Internet to some local users, set quotas for traffic or bandwidth, filter ads and viruses;
Anonymizing access to various resources. The proxy server can hide information about the source of the request or the user. In this case, the target server sees only information about the server, for example, the IP address, but is not able to determine the true source of the request. There are also distorting proxies that transmit false information about the true user to the target server;
Well, it allows you to protect the client computer from some network attacks.
Proxy servers are divided into open and closed. Open – these are those that any Internet user can access. Closed, of course, vice versa.
In this article we are interested in open proxies, and therefore we will consider them more closely.
Open proxy – anonymous and regular
An open proxy server is a server that allows virtually any network node (client, tobish, say, you) to communicate through itself to other network nodes (to all kinds of sites or somewhere else).
For reference: when I say the network, I mean not only the local, but also the Internet.
Open proxies are also divided into two subspecies:
Anonymous and ordinary.
Anonymous ones are those that hide the real IP addresses of clients and thereby provide the opportunity to anonymously use the services of the Internet.
Ordinary are ordinary, they do not hide anything from anyone and give out your real IP and all other typical data.
In addition to anonymity, in the event of a difference in the price of traffic on different networks, an open proxy server located in your own network can be used to get more expensive traffic from a foreign network. So, for example, many Russian users who are denied access to foreign sites at work can still get this access through an open proxy server.
As for the speed of work, it is much less, because, in fact, the traffic, in the form of a request, goes through an additional server, and these delays are much larger than with a request directly. Open proxies are used, as a rule, to perform a specific operation, when speed is not important, but goal achievement (access to some resource, etc., etc.).
As you understand, an open proxy poses a problem, since such anonymity can allow you to violate the law and conditions for the provision of services on the Web with impunity, and therefore, as a result, the sites of some Internet services prohibit access to their resources from open proxy servers (for example, – these are Yandex postal services).
Ok, the theory is stated. Let’s get down to practice.
How to work through a proxy server?
There are several ways to work through a proxy: this is either through network settings (globally) or by program settings (pointwise, that is, say only for the IE browser).
In this article, we will consider the global option for changing settings, and already within the framework of all the others, I will tell, as, for example, based on a plug-in for Firefox or a program for the entire system.
I want to say right away that the option of global change in settings, frankly, is not entirely global. The fact is that in Windows there is no concept of a global proxy as such, there is only the ability to configure a “conditionally global option”, that is, only for such programs that can take proxy settings from Internet Explorer. For all others, you will have to specify desire to use proxies in their own (programs) settings.
First we need to find an open proxy server. You can do this with a simple Google request: “list of anonymous proxies” or “list of open anonymous proxies” or “open proxy list” or whatever else comes to your mind. There are quite a lot of sites with proxy server lists, though far from all of them work, so you will have to torment yourself when selecting.