Why do you need a proxy server in an enterprise? What is a proxy server and why is it needed? Why are proxies needed?

28.02.2020

A proxy server (from the English proxy - “representative, authorized”) is a service in computer networks that allows clients to make indirect requests to other network services. First, the client connects to the proxy server and requests some resource (for example, a file) located on another server. Then the proxy server either connects to the specified server and obtains the resource from it, or returns the resource from its own cache (in cases where the proxy has its own cache). In some cases, the client request or server response may be modified by the proxy server for certain purposes

A proxy server is an intermediate computer that acts as an intermediary ("proxy" - intermediary) between your computer and the Internet. All your requests on the Internet pass through it. Proxy processes them and transmits the results (files downloaded from the Internet) to you.

A proxy server can do a lot. He is capable of:

speed up your work with the Internet;
make your journey on the Internet anonymous;
allow you to enter chats even if you are blocked;
help you view those sites to which your system administrator has blocked access;
and much more.

Proxy classification:
There are several types of proxy servers. Each type of proxy is designed to solve its own range of problems, but they have much in common and their capabilities largely coincide.
HTTP proxy

This is the most common type of proxy server and when we simply say “proxy” we mean it. Previously, using this type of proxy, you could only view web pages and pictures, and download files. Now new versions of programs (ICQ, etc.) can work via an HTTP proxy. Browsers of any version can work with this type of proxy.
Socks proxy

These proxy servers can work with almost any type of information on the Internet (TCP/IP protocol), but to use them, programs must explicitly indicate the ability to work with socks proxy. To use socks proxy in the browser you need additional programs(browsers do not know how to work via socks proxy). However, any version of ICQ (and many other popular programs) can work perfectly through socks proxy. Finally, please note: when working with socks proxy, you need to specify its version: socks 4 or socks 5.
CGI proxy (anonymizers)

This type of proxy server can only be worked through a browser. In other programs their use is difficult (and it is not necessary - there is an HTTP proxy). However, since this type of proxy is initially designed to work through a browser, they are extremely easy to use. You can easily not only use the anonymizer in your work, but also easily build a chain of CGI proxy.
FTP proxy

This type of proxy server separate from corporate networks is quite rare. Typically, its use is due to the fact that the organization has a Firewall (a system for protecting computers from outside intrusion) that prevents direct access on the Internet. The use of a proxy of this type is provided in many popular file managers(FAR, Windows Commander), download managers (GetRight, ReGet, ...) and in browsers.
This type of proxy is highly specialized and is designed to work only with FTP servers.

How to determine the proxy type?
First of all, let’s separate these types of proxy servers from each other in essence:

HTTP proxy is a “regular” proxy server that is most common. You can use this proxy by configuring your browser and many other programs (the programs must provide for the use of a proxy server; if the type of proxy used is not specified, then it is an HTTP proxy).
SOCKS proxy - browsers cannot work with this type of proxy server, but many popular programs provide for the use of this type of proxy server (for example, ICQ). If the program requires such proxies, the type of proxy server (SOCKS) is always indicated, and the subtype (version) of the SOCKS proxy server is almost always required: SOCKS 4 or SOCKS 5 (sometimes SOCKS 4a).
Anonymizers (CGI proxy) are a web page whose address you simply need to type in the browser address bar (for example, http://www.anonymizer.com/). There is no need to change any program settings, configure the browser, etc. - just open a web page. Other programs (except browsers) in 99.9% of cases do not know how to use anonymizers.

Now about the “external” differences between these types of proxy servers:

Since a CGI proxy is a web page, the address of such a proxy begins with http:// or https:// and contains the path to web page(for example http://www.server.com/nph-proxy.cgi). The anonymizer (usually) does not have a port number;
HTTP and SOCKS proxy - consist of a server name (host) and a port number, which are separated by a colon (usually) or a space:
www.server.com:5731
SOCKS proxy - in 90% of cases they have a port number of 1080, 1081 or similar;
HTTP proxy - in 90% of cases they have a port number of 80, 8080, 81 or 3128;
In addition, you can determine the type of proxy server by using any proxy checker: by checking the proxy first for one type and then for another (HTTP / SOCKS). In 99.999% of cases, the proxy is either HTTP or SOCKS (although it can be both at the same time);
HTTPS proxy: this type of proxy server is one of the subtypes of HTTP, so it can only be identified by checking it with some kind of proxy checker.

What is the difference between a free proxy server and a paid one?

Advantages of paid proxy servers

You choose the server yourself according to the characteristics that suit you (such as server response time, speed, caching efficiency, anonymity, etc.);
You can choose a proxy server of any country you need and not think about the fact that the proxy will soon “die” and you will have to look for a new one;
The server's operation is stable - in case of malfunctions, you can make your claims.

Disadvantages of paid proxy servers

You have to pay money ( subscription fee) for the service provided; In addition, you pay for the amount of information downloaded (traffic fee);
Although the paid proxy server is stable, it may also experience glitches. This is especially offensive - after all, I paid the money;
A paid proxy server, by definition, cannot be absolutely anonymous - it is enough to get to your proxy, and then contact the organization that provides you with a paid proxy server. True, this is only available to organizations like the FSB and the CIA (and maybe not only);
Although paid proxy servers, of course, can be built in a chain (after all, you choose the server yourself when you buy this service), it is still unlikely that you can afford to pay for a chain of, say, 5 proxy servers;
It is difficult (if not impossible) to switch between different proxy servers - unless of course you pay for multiple proxies.

Advantages of free proxy servers

Of course, their service is absolutely free;
You can easily use several proxy servers - if you are not allowed into the chat, enable the use of proxy - and go ahead;
In terms of their characteristics (speed, response time, etc.), free proxies can be on par with their paid counterparts;
If your proxy server is anonymous, then it is much more difficult to track you over the network (for example, to attack);
You can build proxy servers in a chain, this will dramatically increase your anonymity (and, note, it will most likely sharply reduce the speed of data exchange with the Internet);

Disadvantages of free proxy servers

Since the service is free, its quality in 99% of cases leaves much to be desired: low speed, constant crashes, etc. and so on.;
There are practically no long-running free proxies. As a rule, after some time they either become paid or stop working;
Many proxy servers are not anonymous - their whole purpose is to cache information received from the Internet;
Some free proxies themselves are not secure (!) Example: when connecting to some proxy servers, the proxies themselves may try to connect to you - for different purposes, for example, to hack your computer and turn it into another “proxy”;
It is quite difficult to find free proxy servers that suit you. Lists of free proxies are 70% repeating each other, more than 90% of these lists are already out of date (many of the proxies in them are not working).

A proxy is an intermediary link between the computer used by the subscriber and the system of Internet servers. Without going into terminology, this is a remote intermediary computer for the user to access the Internet. Its main tasks are to broadcast all user requests to the Network and send back the received responses. We will tell you more about what a proxy is, how the server works and for what purpose it is used.

How a proxy connection works

Each computer from which you access the Internet is assigned a unique IP address. Its task is to identify the Internet user. The IP address carries information about the country and region, Internet provider number and personal computer on his network. Proxy servers are also assigned unique IP addresses. After connecting to the proxy and transmitting requests to the Network, verification will show that they come from an intermediary server, and the subscriber himself will be able to remain incognito (in the case of working with free servers, information about the client is saved on paid servers).

To connect to a proxy, you will need to make settings in the browser that will be used to send user requests. All subsequent network connections will be executed to the IP address of the proxy server. When you need to access any web resource, the local computer will open a connection to the proxy and make a request. After checking the correctness of the request, a connection to the resource will be opened. Then the received response will be transmitted to the subscriber's computer.

Why and who needs a proxy

Today, proxy servers are used mainly to hide the true IP address. There may be several reasons for this. The most popular are the desire to visit a site to which access is blocked for your IP, and the need to send mail anonymously. There are several other reasons when you need a proxy:

network security or local computer from some species network attacks and the need to protect confidential information;
restricting user access to certain types of web resources. Practiced in companies to prevent employees from wasting their time;
desire to connect several computers to the Internet with one IP address. The settings can be made in such a way that information about local machines will be hidden from external machines; only the intermediary will be able to see them;
the need to save consumed traffic - information received from the Network will be transmitted to the user in a compact form;
the need to reduce the load on the Internet channel and provide customers with prompt access to information. For such cases, files are cached and subsequently stored on a proxy server.

Proxies can be found on some sites where they are posted for free. The second option is to download using special software that allows you to use a filter by country and test the speed and operation of the proxy server. And another way is to buy an “authorized” server on special sites.

Advantages

They gained the greatest popularity in the corporate segment - it is through them that access to online networks from local networks is carried out legal entities. The following advantages contributed to this:

proxy servers are supported by the vast majority of well-known web browsers;
carried out full control access, convenient traffic accounting, its filtering (in cases of integration with antiviruses);
ability to work with minimal rights on any operating system;
the absence of Internet access via other protocols significantly increases the security of information exchange on the corporate network.

Despite the increasing popularity of certain network protocols, proxy servers continue to dominate the enterprise. This is despite the emergence of relatively inexpensive hardware routers with NAT functionality. This is mainly due to the fact that the above routers are not able to provide sufficient control over Internet access and content filtering.

Kinds

Transparent- a communication scheme that redirects part of the traffic (or all) by the router to the proxy server. The advantage of this type of communication is the client’s ability to enjoy all the benefits of a proxy server without making any settings. This is also a disadvantage, since it deprives the user of choice.

Back- a proxy server used to balance the network load between several web servers. In addition, its task is to increase their safety. In this case, the reverse proxy server plays the role of firewall at the application level. When using it, user requests are relayed from the external network to one or more servers located on the internal network.

In addition to the fact that proxies are divided into transparent and reverse types, they can be classified as follows:

HTTP- the most popular and universal type of proxy that can be used to solve a wide range of problems. Most modern software supports working with it;
Socks- a type of proxy with which not every program is compatible. Requires installation of additional software in browsers, since they do not support Socks by default;
CGI- interaction with them is carried out only through the browser; other software does not support CGI. Another name for this type of proxy is an anonymizer;
FTP- a type of proxy often used in corporate networks as one of the components unified system protecting equipment from external threats.

In this article we will try to tell you as simply and easily as possible about what proxy servers are and where you can buy them. In addition, we will dwell a little on classification (i.e., we will tell you whatproxy there are). If you are just discovering cyberspace and want to have at least something in its vastness (money, fame, pleasures, etc.), then you will really like this educational program - we won’t load it. All you need is to read the material, understand the basics, and then act according to the circumstances, namely, you either continue to study the topic (in order to become an expert in everything related to proxy), or, based on the knowledge gained, reap the benefits that this miracle Yudo will supply you (and this, without any doubt, will happen).

Let's start the story a little unconventionally and define " a proxy server is..."We'll give it a little later. Let's start with a banal example that very clearly demonstrates why some mere mortal users actively begin to delve into the network in the hope of finding a well-functioning proxy server.

Look.

Imagine this: you are connected to the Internet and want to download music. There are quite a few places where this can be done, but, unfortunately, it very often happens that the very music you need is located in only one place. Either you don’t know how to use search engines very well, or indeed the archive with the album you need is posted only in a single copy - in a word, the devil only knows - it’s not anywhere else, even if you crack it!

So. Now you have found the opportunity to download what you need and click on download. Clap - you get a free one upload host entitled rapidshare.com. Great! We are waiting for the allotted time because... for freeloaders who do not buy a premium account, there is always a short wait before jumping. The required 60-70 seconds passed and the desired button appeared Download file.

But no such luck - it turns out that someone is already downloading from RapidShare, and on top of that, from your IP address! The world is cruel and the system is not going to give you the go-ahead to download a file - it simply says - " wait until they download and then try again". You wait, wait, wait... And so on endlessly.

But the point is this - you have a static IP address and your provider, to put it mildly, is very bad (if you can afford such things).

Well, what should you do - you say - how to download from Rapidball? Well, yes.. The answer is on the Internet - and so you break into it in order to figure it out and understand, and then make it work. And, of course, the first thing you will find on the Internet if you type in Google is " how to download from rapidball", will helpful advice - "use a proxy and you will be happy!"

Oops. What is a proxy? What do you eat it with? Where can I get it? How to set it up? Yeah... There are many questions, and you are alone... But don’t despair! Now we will tell you everything (well, almost everything!)

What is a proxy server.

A proxy server is an intermediate computer that acts as an intermediary (from the English "proxy" - intermediary) between your computer and the Internet. All your calls to cyberspace go through the proxy server. The proxy server processes these requests and sends the results (for example, files downloaded from the Internet) back to your computer.

If you explain it in simple words, then technically the procedure for operating a proxy server looks like this:

- you configure your browser to the appropriate proxy server (see below for how this is done);
- the browser sends a request to this proxy server through your provider;
- the proxy server (if it is working and good) sends a request to the site you need;
- the site (if it is not evil and trusts a good proxy) accepts the request and provides the proxy server with the information it requires;
- proxy, accepts this response and sends it to you (again, through your provider);
- your browser accepts the received data;
- you save a file to the screw or look at the page of the required site.

Thus, from the provider’s side, your activity on the Internet looks very weak, because... you constantly visit the same website (a proxy server, like a website, has a unique IP address). But, in fact, you download the required data from all over the Internet, and the provider cannot even guess where you are and what interests you.

Read the last sentence carefully again, because... proxy servers are not only an opportunity to download from rapidshares, but also anonymity on the Internet.

By the way, we’ll talk about anonymity later, but now let’s once again return to the theory of using proxy servers in everyday life.

Everything that an ordinary network user needs to do in order to use a proxy server can be expressed in three points:

- you need to find the proxy server address . The address could be, for example, something like this - 59.39.71.201 8080. The last four digits are the port (this will also need to be entered into the browser);
- you must enter the existing address into a special proxy form in your browser (this is done through the proxy settings, which you can easily find if you go to the “options”, “settings” section, etc.)
- Enter the address of the required site in the address bar of the browser and press the "enter" button.
And that’s all - now all the sites you visit will receive requests exclusively from the new IP address that belongs to the proxy server you have chosen.

At the beginning of the article we gave an example with a rapid ball. So - using good proxy servers, you can pump up tones from there useful information, which was previously not available to you due to the static IP address that you were awarded by the commitment of many domestic providers to the collective farm system.

What other benefits are there from proxy servers?

1. A proxy server can speed up your surfing.

There is no point in dwelling on this issue, because... It’s already the 21st century and high-speed connections (1 megabit and higher) are now not uncommon. Five or six years ago, this question interested many; now, proxy servers are used for other purposes;

2. A proxy server makes your online travel anonymous.

Alternative option

3. Using proxy servers, you can access sites that are blocked by your ISP or network administrator.

For example, you are sitting at work and want to write something on your LiveJournal, but the admin (of course, it’s not him - he was ordered!) has blocked access to livejournal.com. In this situation, you should do this - set a working proxy server in your browser, go to LiveJournal and make a post about the admin and his superiors. But! Jokes aside, for many people in this world, proxy servers are a window to the free Internet - for example, in China, proxy servers are used to visit sites banned by the Communist Party.

4. Using proxy servers, you can filter the content of loaded web pages (for example, get rid of advertising).

This is rarely used, because In order to cut out ads, you just need to set up your firewall or, say, your favorite Mozilla.

5. Using a proxy server, and without much difficulty, you can change your “geographical location” on the network.

geographical reference

6. If the proxy server is located in local network(i.e. on the same local network as you), then it is enough that only this proxy has a connection to the Internet - the entire network will be able to access the Internet through this proxy (collective farm version).

Here you go.

Now a few words about what kinds of proxy servers there are.

To begin with, we note that in an educational article it is very difficult to give detailed description types of proxy servers, but we won’t do this - why? If in the future you need to obtain more complete information, we recommend that you turn to specialized sources (there are a lot of them on the Internet - a Google search will give good results!).

There are four types of proxy servers and each of them is designed to perform a specific range of tasks. But despite this, they have a lot in common, and the capabilities of all four types often coincide.

1. HTTP proxy

HTTP proxy is the most common type of proxy server and, most often, when they say “use a proxy server,” they mean HTTP proxy. All types of browsers support this type of proxy server - moreover, programs such as, say, ICQ chatter can also connect via HTTP proxy. Previously, the situation looked somewhat different - using an HTTP proxy, you could only view web pages and download pictures.

2. Socks proxy

This is the most universal type of proxy servers, because... knows how to work with any information that circulates on the Internet (TCP/IP protocol is used). Despite their versatility, Socks proxy servers have a more limited distribution (compared to HTTP proxy), because not all programs support such a connection. For example, browsers themselves do not know how to work with Socks proxy, and in order to set up such a connection through a browser, you need to install special plugins or even programs. However, the above-mentioned ICQ chatter (and other applications) easily work through Socks proxy - many thanks to them for this. There are two versions of Socks proxy - socks 4 and socks 5. In order to set up a connection, you need to choose one.

3. CGI proxy

use of CGI

4.FTP proxy

File Transfer Protocol)

In conclusion, it should also be noted that proxy servers can be paid or free. For domestic (and near-domestic) purposes, it is strongly recommended to use exclusively the second option - because finding a quick one free server you will not feel any difference, and the money will remain with you.

The addresses of free proxy servers you can very large quantities found, for example, on www.FreeProxy.ru, and at this address you can buy paid anonymous proxy servers. Moreover, this portal has a section of articles in which the issue of everything related to proxy servers is discussed in great detail + there is not only a wonderful FAQ, but also a forum. There is also a section from which you can download programs for identifying working proxies.

What is a proxy server is a computer on the Internet (more precisely, a service on the computer), which allows you to make not direct, but indirect requests to other network resources. Such a server is an intermediary between your computer and a resource on the Internet. It helps you stay anonymous when traveling online.

Where can I find the proxy server address? Many providers provide clients with their proxy addresses. But you can also use others. They are easy to find on the Internet. Most often, a proxy server is specified by an IP address and port number. To enable a proxy server for your browser, you must specify the proxy address and port in its settings. (For example, 188.134.19.102:3129) In Firefox it is written like this: Settings - Advanced - Network - Configure

Why do you need a proxy server? I'll explain on simple examples.. You need to download a cartoon, program or book from a file hosting service. And when you log in, you receive a message indicating that your IP address limit has been reached. The reason may not be your fault at all, since you haven’t downloaded anything yet. But your provider distributes one common address to half of the area, which is recorded by the file hosting service. What to do in this case? You can, of course, wait a few hours, but there is no guarantee that your quicker neighbor won’t get ahead of you again. It is much easier to open a list of sites that have free proxies and access the file hosting service through them.

A proxy server is very convenient for use on a local network, when several computers use a common Internet connection.

If you frequently access the same external resources, a copy of them on the proxy server is provided upon request. So external network. And the requested information is transmitted to the client faster. Another option is that during your lunch break at work, you would like to go to your favorite social network and congratulate your girlfriend or friend on something. But your prudent bosses long ago blocked all social networks so that employees could work productively and not chat with friends or look at pictures. But login through proxy server maybe you will succeed.

You can also use other proxy features, for example, use them to hide annoying advertisements. Through a proxy you can hide your geographical location. For example, if you told your annoying girlfriend or friend that you went on a business trip to Spain, and you yourself are chatting from the next street. Change the country via proxy and you are already in Madrid.

On November 1, 2017, a law prohibiting the use of anonymizers to access blocked Internet resources came into force. Anonymizers, VPN services, and even browsers with traffic proxying functions are banned in Russia. In a word, all those tools that allow you to bypass sites on the Internet blocked by Roskomnadzor.

But do not forget that your data transmitted to the Internet through a proxy is also cached on it and can become accessible to attackers. Don't use proxies server for operations with your electronic wallets and for important correspondence.

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Surely many Internet users have ever heard the word “proxy”, but did not attach any significance to it and conveniently forgot it, believing that it belonged to the area of knowledge of professional programmers and hackers. But this is not true at all. What is it and why is it needed for the average user?

Proxy server: what is it and what is it used for?

The modern world can no longer imagine its life without round-the-clock exchange of information in various social networks, forums, blogs and other opportunities that the Internet provides us. But the World Wide Web is not a library that anyone can enter and take everything they need. Here the conditions are a little stricter. When requesting information from a site or simply following a link, the computer transmits some identification information to it, such as:

A unique IP address of a computer on the network;
Information about the Internet connection operator;
User location data.

And based on it, the site opens or denies user access to the resource. This practice allows you to secure certain sites from unwanted users or generally narrow the circle of those who can visit them. And at this stage, problems arise for the user - pages may deny access to people from other countries or cities, and all that the Internet surfer will have to be content with is a message with the inscription: “Not available for your region.”

A proxy server helps avoid this. This system acts as an intermediary between the computer owner and world wide web. It independently processes the request and after that transfers the information to the resource. Proxy servers check whether a connection can be established with the desired resource and find a way to do so.

Why do you need a proxy server?

Despite the apparent complexity of the work, “proxy” is a very useful thing that can be useful to the user in a lot of cases. The most popular include:

Hide your real location. A proxy server can be used to gain access to regionally protected servers. Since most proxies change the user's IP to another one, regional site, you just need to connect to the server and access the site through it;
Hide your IP address. A less popular, but also very convenient function of such servers. If for some reason you need to hide your address on the Internet, then you can’t think of anything better and easier than using a proxy;
Ensuring the security of a site, page or computer network companies. One or more “proxy” servers can serve as a kind of shield-partition between the company’s network structures and the rest of the Internet, hiding all computer network data and providing secure access to web information.

Types of proxies

There are many different proxy servers, but the most convenient and common ones include:

HTTP servers. They allow you to save downloaded files and download them from the “cache”, significantly increasing the speed of work and reducing the traffic used, create lists of unwanted sites, limit the activities of some users on the network and provide many other functions;
HTTPS servers. They work in almost the same way as the first type, but have increased safety and security, which allows them to be used to transfer secret or valuable information such as logins, passwords and bank card data;
Sosks. It is considered the most secure server, completely protecting user data and making visiting sites completely anonymous.

Setting up a proxy

For Windows browsers support is provided huge amount plugins that allow you to change proxies and work with sites anonymously and securely. To do this you need to download one of free plugins to your computer and install it in your browser. For example, the most convenient ones are Browsec and friGate. Both of them work quite simply and are not difficult to understand, but the second provides more options for interacting with proxy servers.

When setting up, you can do without plugins - each browser has a pre-installed ability to change proxy values. Usually this can be done in the “Settings Menu” tab - “Settings” - “ Additional settings" - "Change proxy".