Problems with VPN and ways to solve them.

Errors in Windows 10

Previously, the state had a rather mediocre understanding of the Internet, so it did not legally interfere with users. Today, while walking on the World Wide Web, you can increasingly come across the phrase: “This site is included in the register of prohibited sites” or “Your ISP has blocked access.”

So, if you want to regain complete freedom of action on the Internet and acquire another level of protection, then you definitely need to familiarize yourself with the technology of virtual private networks - VPN.

VPN: term and principle of operation

Virtual Private Network (VPN) is the name of a technology that allows the creation and overlay of one or more networks on top of any other user network.

Now, how exactly does a VPN work? Your computer has a specific IP address that blocks access to certain sites. You enable VPN technology through some program or extension. VPN changes your address to an address from a server in another country (for example, Holland or Germany).

Next, a security connection is created, which cannot be blocked by the provider. As a result, you get a secure protocol through which you can freely visit any Internet site, and completely anonymously.

Structure and types of technology

The whole technology works in two layers. The first is an internal network, the second is an external one. When you connect to the technology, the system identifies your network and then sends an authentication request. This technology is very similar to authorization in some social network, only here everything is carried out through secure protocols and without the participation of the provider.

Virtual networks themselves are also divided into several categories. The main classification is based on the degree of protection, that is, the user can use both paid and free VPNs.

The difference between them is the secure connection. For example, subscription systems will give you secure protocols such as PPTP, IPSec and others. While free VPNs often provide only “trusted” channels. That is, your network itself must be highly protected, and a VPN will only enhance the level of protection.

A subscription to paid VPNs does not exceed $10 per month, but not every user needs it. For ordinary tasks, there is no point in purchasing Premium accounts; standard capabilities are sufficient.

Reasons to use a VPN

Every user needs to use VPN technology, and here's why:

Data protection. Especially suitable for those users who like to connect to a neighbor’s “free” Wi-Fi connection, and then discover that their card data has been stolen. Such situations include gatherings in cafes and generally in any places with free Wi-Fi.
Complete anonymity. When you open a new tab with a website, this action will be displayed on the provider’s server, so your journey on the Internet can be tracked by any employee of the company. By turning on a VPN, you will hide your browsing history because you are using a different IP address.
The ability to surf the Internet without obstacles. Bookmakers, online casinos, torrents, forums, sites for adults - all the “underground” of the Internet is again available to you, everything is like in the old days.
Use of foreign resources. It is, of course, unlikely that you will use English-language services such as hulu.com, but still, you are provided with full access to all popular sites around the world.

How to use VPN on a computer?

Let's consider a situation where we use a regular browser and want to visit blocked sites. In this situation, you can go two ways:

install the VPN client (program) on your PC;
add a browser extension via Webstore.

Both the first and second options are easy to implement, but for the full picture, let’s consider both.

You can also use the free one.

To install a VPN client, you need to download a program on the Internet, for example, “Betternet”. Run the installation file and install the client. We launch it, click: “Connect” and that’s it. The problem is that the program automatically gives us a random IP address, and we cannot select a country, but by pressing just one button we are already using a VPN. And one more disadvantage is the need to constantly launch the program, however, some clients have the ability to launch it simultaneously with the OS.

The second way is to add an extension. The downside here is that, most often, registration is required to use it, plus the extensions have the ability to crash. But the extension is much easier to use - click on the icon in the browser, select the country and profit. At the moment, there are thousands of similar programs, you can choose any of them, for example, “Hotspot Shield”. Add the extension to your browser, register and there will be no more technical issues.

For example, this is how the ZenMate VPN extension works in the browser:

We wrote about VPN extensions for different browsers in the article: .

How to use VPN on mobile devices?

We will look at those devices that have popular operating systems on board, for example, iOS or Android.

Using a VPN on smartphones or tablets is also quite simple, namely through mobile applications. The problem is that some programs require root rights, and these are additional hassles, plus the possibility of turning the phone into a “brick”. So look for programs that do not require you to have root rights. On Android, for example, it is OpenVPN, and on iOS it is Cloak. You can also use the free and proven one on iPhone and iPad. I use it myself sometimes, it works great.

The download technology is very simple: download the application from the Play Market or AppStore and install it on your device. Next, we activate the VPN, select a profile (from where we will get the IP address), then make a connection and that’s all. Now you are browsing the Internet through a VPN, which the application you are using will tell you about.

Now you understand how VPN connection technology is implemented, and now your online experience will become more secure, anonymous, and most importantly - accessible and unlimited.

They have become commonplace. True, no one really thinks about what is behind the concept like “VPN, setup, use, etc.” Most users prefer not to delve into the jungle of computer terminology and use standard templates. But in vain. From knowledge about such connections, you can derive a lot of benefits, for example, increase traffic or connection speed, etc. Let's see what a connection to a virtual network actually is, using the example of the interaction of Windows operating systems on a desktop computer terminal and Android on a mobile device

What is VPN

Let's start with the fact that VPN setup is impossible without the general principle of understanding the essence of the connection being created or used.

To explain in simple words, such a network necessarily contains a so-called router (the same router), which provides computers or mobile devices trying to connect to an existing network with standard additional IP addresses for accessing the local network or the Internet.

In this case, a virtual network in which there is an activated VPN connection setting accepts any device connected to it and is assigned a unique internal IP address. The range of such addresses in the usual standard is from zero to the value 255.

What’s most interesting is that even when accessing the Internet, the external IP address of the device from which the request is made is not so easy to determine. There are several reasons for this, which will be discussed below.

The simplest VPN setup for Android

Almost all virtual networks using a wireless connection like Wi-Fi work on the same principle - assigning free IP addresses from the available range. It is not surprising that any mobile device can easily be connected to them (but only if it supports the appropriate connection protocols).

However, today any smartphones or tablets based on the Android OS have in their functionality the option of connecting the same Wi-Fi. The network is detected automatically if the device is within its coverage area. The only thing you may need is to enter a password. The so-called “shared” ones do not require a password at all.

In this case, you need to go to the main settings on your smartphone or tablet and activate the Wi-Fi connection. The system itself will determine the presence of radio modules at a distance of 100-300 meters from the device (it all depends on the model of the distribution router). Once the network is identified, a menu will be displayed with all available connections and their blocking indication. If the network has a padlock icon, it is password protected (however, this will be indicated initially in the message). If you know the password, enter it.

In public networks, where login using a password is not provided, it is even simpler. Has the network been determined? All. Click on connection and use it. As is already clear, VPN configuration in this case is not required at all. It’s another matter when you need to use the settings of Windows or another operating system (even a mobile one) to create a connection or assign the status of a VPN distribution server to a computer terminal or laptop.

Creation on Windows

With operating systems of the Windows family, not everything is as simple as most users think. Of course, they automatically recognize a network or connection via Wi-Fi, ADSL, or even a direct connection via an Ethernet network card (subject to the presence of installed equipment). The question is different: if the distributor is not a router, but a laptop or desktop computer, how to get out of this situation?

Main settings

Here you will have to delve into the VPN settings. Windows as an operating system is considered first.

First you need to pay attention not even to the settings of the system itself, but to its accompanying components. True, when creating a connection or using it to the maximum, you will have to configure some protocols such as TCP/IP (IPv4, IPv6).

If the provider does not provide such services automatically, you will have to make settings indicating previously received parameters. For example, when connecting automatically, the fields in the Internet browser properties for filling will be inactive (there will be a dot on the item “Obtain an IP address automatically”). That is why you do not have to enter the values of the subnet mask, gateway, DNS or WINS servers manually (especially for proxy servers).

Router settings

Regardless of whether the VPN is configured on an ASUS laptop or terminal (or any other device), access to the network is still common.

To do it correctly, you need to go to its own menu. This can be done using any Internet browser, provided that the router is directly connected to a computer or laptop.

In the address field, enter the value 192.168.1.1 (this corresponds to most models), after which you should activate the enable function (using the router parameters in advanced mode). Typically this line looks like WLAN Connection Type.

Using VPN Clients

VPN clients are quite specific programs that work like anonymous proxy servers that hide the true IP address of the user's computer when accessing a local network or the Internet.

Actually, the use of programs of this type is reduced to almost complete automation. The VPN setting in this case, in general, is not important, since the application itself redirects requests from one server (mirror) to another.

True, you will have to tinker a little with setting up such a client, especially if you want to make the maximum number of available connections in your home virtual network. Here you will have to choose between software products. And it should be noted that some applications, even the smallest in size, sometimes surpass the commercial products of many well-known brands, for which you also have to pay (by the way, a lot of money).

What about TCP/IP?

It goes without saying that almost all of the above settings affect the TCP/IP protocol to one degree or another. Today nothing better has been invented for comfort. Even remote anonymous proxy servers or local data stores still use these settings. But you need to be careful with him.

It is best to contact your provider or system administrator before changing settings. But one thing must be clearly remembered: even when setting the values manually, as a rule, the subnet mask has the sequence 255.255.255.0 (it can change), and all IP addresses begin with the values 192.168.0.X (the last letter can have from one to three characters ).

Conclusion

However, all these are subtleties of computer technology. The same VPN client for Android can provide communication between multiple smart devices. But the biggest snag is whether it’s worth using such a connection on a mobile gadget.

If you noticed, we didn’t go into too much technical detail. This is rather a descriptive instruction about general concepts. But even that simple example, I think, will help, so to speak, to understand the very essence of the issue. Moreover, with a clear understanding of it, the whole problem will be reduced only to the system settings, which will not affect a specific user in any way.

But here you need to be very careful. Actually, for those who do not know what a VPN connection is, this will not help much. For more advanced users, it is worth saying that creating a virtual network using Windows OS’s own tools is not recommended. You can, of course, use the initial settings, however, as practice shows, it is better to have some additional client in stock, which will always be like an ace in the hole.

The concept of private virtual networks, abbreviated as VPN (from English, appeared in computer technology relatively recently. The creation of a connection of this type made it possible to combine computer terminals and mobile devices into virtual networks without the usual wires, regardless of the location of a particular terminal. Now let’s consider the issue of How a VPN connection works, and at the same time we will provide some recommendations for setting up such networks and related client programs.

What is a VPN?

As is already clear, a VPN is a virtual private network with several devices connected to it. You shouldn’t delude yourself - connecting two or three dozen simultaneously working computer terminals (as can be done in a local area) usually doesn’t work. This has its limitations in the network setup or even simply in the bandwidth of the router responsible for assigning IP addresses and

However, the idea initially inherent in the connection technology is not new. They tried to substantiate it for a long time. And many modern users of computer networks do not even imagine that they have known about this all their lives, but simply did not try to understand the essence of the issue.

How a VPN connection works: basic principles and technologies

For a better understanding, we will give the simplest example that is known to any modern person. Take the radio, for example. After all, in essence, it is a transmitting device (translator), an intermediary unit (repeater) responsible for the transmission and distribution of the signal, and a receiving device (receiver).

Another thing is that the signal is broadcast to absolutely all consumers, and the virtual network works selectively, uniting only certain devices into one network. Please note that in neither the first nor the second case, wires are required to connect transmitting and receiving devices that exchange data with each other.

But there are some subtleties here too. The fact is that initially the radio signal was unprotected, that is, it can be received by any radio amateur with a working device at the appropriate frequency. How does a VPN work? Yes, exactly the same. Only in this case, the role of the repeater is played by a router (router or ADSL modem), and the role of the receiver is played by a stationary computer terminal, laptop or mobile device equipped with a special wireless connection module (Wi-Fi).

With all this, data coming from the source is initially encrypted, and only then, using a special decryptor, is reproduced on a specific device. This principle of communication via VPN is called tunneling. And this principle is most consistent with mobile communications, when redirection occurs to a specific subscriber.

Local virtual network tunneling

Let's understand how VPN works in tunneling mode. At its core, it involves creating a certain straight line, say, from point “A” to point “B”, when, when transmitting data from a central source (router with a server connection), all network devices are automatically identified according to a predetermined configuration.

In other words, a tunnel is created with encoding when sending data and decoding when receiving. It turns out that no other user who tries to intercept this type of data during transmission will be able to decrypt it.

Means of implementation

One of the most powerful tools for this kind of connections and at the same time ensuring security are Cisco systems. True, some inexperienced administrators have a question about why VPN-Cisco equipment does not work.

This is primarily due to incorrect configuration and installed drivers of routers such as D-Link or ZyXEL, which require fine tuning only because they are equipped with built-in firewalls.

In addition, you should pay attention to the connection diagrams. There can be two of them: route-to-route or remote access. In the first case, we are talking about combining several distribution devices, and in the second, we are talking about managing the connection or data transfer using remote access.

Access protocols

In terms of protocols, configuration tools are primarily used today at the PCP/IP level, although the internal protocols for VPNs may vary.

VPN stopped working? There are some hidden options to look at. For example, the additional protocols PPP and PPTP, based on TCP technology, still belong to the TCP/IP protocol stacks, but to connect, say, when using PPTP, you must use two IP addresses instead of the required one. However, in any case, tunneling involves transferring data enclosed in internal protocols such as IPX or NetBEUI, all of which are equipped with special PPP-based headers to seamlessly transfer data to the appropriate network driver.

Hardware devices

Now let's look at a situation where the question arises as to why the VPN isn't working. It is clear that the problem may be related to incorrect equipment configuration. But another situation may also arise.

It is worth paying attention to the routers themselves, which monitor the connection. As mentioned above, you should only use devices that meet the connection parameters.

For example, routers like the DI-808HV or DI-804HV are capable of connecting up to forty devices simultaneously. As for ZyXEL equipment, in many cases it can even run through the built-in ZyNOS network operating system, but only using command line mode via the Telnet protocol. This approach allows you to configure any device with data transmission on three networks in a common Ethernet environment with transmission of IP traffic, as well as use the unique Any-IP technology designed to use a standard table of routers with forwarded traffic as a gateway for systems that were originally configured to work in other subnets.

What to do if VPN does not work (Windows 10 and below)?

The very first and most important condition is the correspondence of the output and input keys (Pre-shared Keys). They must be the same at both ends of the tunnel. It is also worth paying attention to cryptographic encryption algorithms (IKE or Manual) with or without an authentication function.

For example, the same AH protocol (in English - Authentication Header) can provide only authorization without the possibility of using encryption.

VPN clients and their configuration

As for VPN clients, not everything is simple here either. Most programs based on such technologies use standard configuration methods. However, there are pitfalls here.

The problem is that no matter how you install the client, if the service is turned off in the operating system itself, nothing good will come of it. That is why you first need to enable these settings in Windows, then enable them on the router (router), and only then start setting up the client itself.

You will have to create a new connection in the system itself, rather than use an existing one. We won’t dwell on this, since the procedure is standard, but on the router itself you will have to go to additional settings (most often they are located in the WLAN Connection Type menu) and activate everything related to the VPN server.

It is also worth noting the fact that it will have to be installed into the system as a companion program. But then it can be used even without manual configuration, simply by selecting the nearest location.

One of the most popular and easiest to use is a VPN client-server called SecurityKISS. The program is installed, but then you don’t even need to go into the settings to ensure normal communication for all devices connected to the distributor.

It happens that the fairly well-known and popular Kerio VPN Client package does not work. Here you will have to pay attention not only to the operating system itself, but also to the parameters of the client program. As a rule, entering the correct parameters allows you to get rid of the problem. As a last resort, you will have to check the settings of the main connection and the TCP/IP protocols used (v4/v6).

What's the result?

We looked at how a VPN works. In principle, there is nothing complicated about connecting or creating networks of this type. The main difficulties lie in setting up specific equipment and setting its parameters, which, unfortunately, many users overlook, relying on the fact that the entire process will be reduced to automation.

On the other hand, we were now more focused on issues related to the operating techniques of the VPN virtual networks themselves, so setting up equipment, installing device drivers, etc. will have to be done using separate instructions and recommendations.

In this article Mr. Whoer will tell you about 12 possible problems with VPN. This is not a detailed guide to troubleshooting VPN problems, but hopefully the article will tell you what to do if your VPN stops working and how to set up a VPN connection.

1. I'm connecting to the VPN, but I can't see a specific website.

It is possible that you are unable to connect to one particular website, especially if you see that your VPN is working fine and other websites are accessible. Try clearing the cache in the browser you are using (Ctrl + F5). Restart your computer just in case.

DNS settings can also prevent certain sites from loading, read more about this in point 3.

Additionally, the site may not be accessible from your chosen VPN server due to geographic restrictions. Try changing the server country.

2. VPN connection is established, but no data is transferred

Check if you are using another VPN client at the same time as yours. You need to find the VPN among running programs, even if it is in the background. Disable and exit all VPN programs that are installed on your computer except the one you plan to use at the moment.

Also, a problem with Internet connection can sometimes arise if you use one VPN client on several devices at the same time (for example, on a mobile device and a desktop computer) and these devices are connected to the same VPN server. Solution: if it turns out, for example, that the server country Germany is selected on the computer in the VPN client, and on the mobile device too, then try changing the country on one of the devices, say, to Switzerland.

3. Connecting to the site works by IP address, but not by domain name

You can also try connecting to the site you need by its IP address rather than its name. If you can access previously inaccessible resources using IP addresses, this may indicate a DNS problem. Check which DNS servers are configured for use on your computer.

Instructions on what DNS is and how to change it can be found.

4. There is a connection to the VPN, but the sites do not load

Fire up your browser and go to a few different sites to make sure your internet connection is actually working. If your computer is on a wireless network and you're having problems connecting to the Internet or hotspot, you'll need to resolve your wireless connection issues before you can use a VPN.

5. Problems with the VPN client

Make sure that the VPN client was installed exactly as indicated in; reinstall the client, re-enter your login information.

1. Uninstall the application
2. Restart your computer
3. Install the client
4. Restart your computer
5. Try connecting

6. Connected to the VPN server, but there is no Internet

If some servers connect and others don't, then the problem is related to the location of the server you connected to when you launched the VPN client. Try reconnecting, perhaps one particular server is not working, but other servers in that country are working. You can also try restarting the client, this is especially recommended if this is your first time trying to connect to the server since installation.

7. Problems with the VPN protocol

Select the “Use UPD connection” option in the settings.

8. VPN doesn't work on your home network

If you're using a laptop or mobile device, visit a free public wi-fi hotspot (cafe, library) and try connecting to the VPN from there.

If the VPN works when connected through a hotspot network, you should look for the problem in your home network. You may need to change some network settings that may be causing problems with VPN access.

9. Programs block VPN operation

Firewall and anti-spyware software may interfere with VPN performance. Antivirus software may also have VPN restrictions set by default. Firewalls are usually not a problem. However, some older versions do not work properly with a VPN connection. To find out if this is your case, temporarily disable your firewall and try to connect to the VPN server again. If the problem is with your firewall, you may need to open some outgoing ports, which may vary depending on the VPN and firewall software.

You can also try disabling the security software and try connecting to the VPN client again. If this doesn't help, try adding the VPN client as an exception to your firewall and antivirus software and unblocking the ports commonly used for VPN connections: TCP 443, TCP 1701, and TCP 1723.

10. Your home router (router) does not support VPN

Some routers do not support VPN Passthrough (a feature of the router that allows traffic to pass freely through the Internet) and/or the protocols required for certain types of VPNs to operate. When purchasing a new router, be sure to check if it is marked as VPN-compatible.

If you're having trouble connecting to a VPN, do an online search for your specific router brand and model plus the word "VPN" to see if there are any reports that your router model isn't working with VPN and if there's a way to fix it .

Your router manufacturer may offer a firmware update that includes VPN support. If there is no such update, you will have to purchase a new home router, but first contact your ISP technical support for advice.

11. Problems with router settings, VPN transit and VPN ports and protocols

If you determine that your router model supports VPN Passthrough, check your router and personal firewall configuration settings on your home network for the following settings:

In the security settings, you can find options for setting up a VPN connection, such as enabling IPSec Passthrough and PPTP Passthrough. These are the two most common types of VPN connections. You can try enabling both.

Check port forwarding and protocols. Your firewall (inside the router and separately in any firewall programs you have installed) may require transmission over certain ports and open protocols. IPSec VPNs must have forwarded UDP port 500 (IKE), and protocols 50 (ESP) and 51 (AH). For PPTP, Microsoft's VPN tunneling protocol, you will need TCP forwarded port 1723 and IP protocol 47 (GRE).

It's not as difficult as it seems. First, read the router's user manual or search the manufacturer's website for information regarding “VPN.” You need to find something that applies specifically to your specific device model.

12. Problems that arise when connecting to a local network.

A VPN will not work if your IP address is in the same range of IP addresses that your local network uses. An example of this is your computer's IP address is 192.168.1. , this means that the network uses the 192.168.1 addressing scheme. .

To find your computer's IP address in Windows, go to Start > Run... and type cmd to launch a command window. In this window, type ipconfig /all and press Enter. Locate the network adapter and check the IP address field.

If you find that your IP address matches the IP address range, you need to make some changes to your home router settings.

Go to your router's configuration page and change the router's IP address so that the first three blocks of numbers in the IP address are different from the IP subnet (in our example: to 192.168.2.1.)

Also find the DHCP server settings and change it so that the router issues IP addresses in the required address range (in our example: from 192.168.2.2 to 192.168.2.255.)

Additionally, watch our video, where we also talk about emerging problems with VPN for users

For today, it would be useful to consider a few questions related to VPN - what it is, what its features are and how it is configured.

The fact is that many people today do not know anything about this technology, although now such knowledge can be very useful.

Even if you look at it from a mercantile point of view, setting up a VPN costs very good money.

Therefore, it would be good to explain in simple terms what a VPN is and how you can set up this technology on Windows 7 and Windows 10, the most popular operating systems at the moment.

Basic information

In general, VPN stands for Virtual Private Network, that is, a virtual private network.

To put it simply, this is a technology that allows, but not using physical devices such as switches and routers, but using Internet resources.

Essentially, a VPN creates one local network on top of another.

On the Microsoft website you can find the picture shown in Figure 1. There you can clearly see what is meant in the phrase “creates one local network on top of another.”

In practice, this is exactly what happens.

In this picture you can see devices in the form of computers. The cloud implies a shared or public network, most often this is the most common Internet.

The two servers are connected to each other using a VPN.

Moreover, these devices are also physically connected to each other. But in practice this is not at all necessary.

This is precisely why the technology in question is needed - not to use cables and devices, but to make do with conventional technologies that transmit information.

Yes, they also require cables, but they are not required for a specific VPN device.

Reference: A local network is the connection of several devices into one network, which allows them to use each other’s resources.

As mentioned above, in physical local networks, devices are connected to each other using optical cables, twisted pairs, radio channels, as well as Wi-Fi, Bluetooth, GPRS, as well as various devices such as routers.

So, in virtual networks, instead of all this, the most common Internet connection is used.

Of course, access to various devices is not granted just like that; they have their own levels of identification, which are aimed at “not letting strangers” into a particular VPN network.

Now let's talk in more detail about how the connection occurs in a Virtual Private Network.

A little about the structure

There are two parts to a VPN structure: internal and external.

Each individual computer is connected to both of these parts simultaneously. This is done using a server.

The server in this case acts as a kind of face control at the entrance to the club. It determines who logs into the virtual network and who goes to seek their fortune elsewhere.

The computer that connects to the VPN must have authentication data with it, that is, some kind of one-time password, smart card or other means that will allow you to go through this procedure.

For us this is not particularly important, it is important that there is an authentication process at all.

Today, specialists from various large companies are developing new authentication methods.

If we return to the same example with face control at the entrance to the club, then the person who comes to the club should know:

Firstly, his name, which will allow him to go through the identification process;
Secondly, he needs to know, for example, a one-time password, which is needed to pass authorization.

In exactly the same way, a computer that comes and wants to join one of the VPN networks “carries” with it its name with a means of authorization.

The server enters the above information into its database, in particular, the name of the connected computer.

In the future, “face control” will no longer require the incoming “client” to provide his data.

In principle, it should now be clear how VPNs work and what they are.

In fact, in practical application everything is much more complicated and, if you want to become a network specialist, you will need to know quite a lot of information.

In particular, this information concerns types of VPNs.

VPN classification

The full classification of this type of technology is shown in Figure No. 2.

Now let's look at each type of classification in more detail.

The classification criteria are:

Degree of protection. According to this criterion, there are such networks:

Fully protected– based on inherently secure networks;
“Trustedly” protected– lower degree of security, used when the “parent” network has a sufficient degree of reliability.

Method of implementation. According to this criterion, the following types of networks are distinguished:

By hardware, that is, using real devices (this type still deviates a little from the canons of a classic virtual network, which does not use all kinds of devices);
By software;
Combined method.

Purpose. Within this criterion, there are the following types of VPN:

Intranet– most often used in companies where several branches are united;
Extranet– used for organizing networks where there are not only internal corporate participants, but also clients;
Remote Access– used to organize networks in which there are remote branches (most often these branches are staffed by one person remotely).

According to the protocol. Although it is possible to implement VPN using protocols such as IPX and AppleTalk, in practice only TCP/IP is used. The reason is very simple - this particular protocol is used everywhere on the Internet and developers simply don’t see the point in “reinventing the wheel.”
By level of work. Here everything corresponds to the classic OSI model, but VPN works only at the data link (transferring information over channels), network (providing a connection) and transport (providing data transfer) levels.

Of course, in practice, one network embodies several classification features at once.

Now let's move on directly to how to set up a VPN network using a very ordinary computer.

Setting up a virtual network

First, let's understand how this is done on Windows 7.

On this operating system, configuration occurs using the following relatively simple steps:

Open the “Network and Sharing Center”. To do this, right-click on the network connection icon in the quick access panel and select the appropriate item from the drop-down menu.

It is worth saying that the network connection icon may not look the same as shown in Figure 3. It can also have the appearance that can be seen in Figure 4.

In the window that opens, you need to click on the item called “Setting up a new connection or network” (highlighted in Figure No. 5).

In the window that opens, you need to select the “Connect to a workplace” item and click the “Next” button (highlighted in Figure No. 6).

If any VPN connections already exist on this computer, the window shown in Figure 7 will appear. In it you need to select the item “No, create a new connection” and again click the “Next” button.

In the window that appears, click on the “Use my Internet connection (VPN)” item. There is no Next button here. There's nothing wrong with that.

Now you will need to enter the address and name of the VPN network. As the window for creating a connection in Windows 7 suggests, you can find out about it from your network administrator.

If you are joining an existing network, you need to ask the administrator for this information. Usually this is not difficult.

They are entered into the fields highlighted in Figure 9.

In the same window, you need to check the box next to the words “Do not connect now...”, and then click the “Next” button.

Now all that remains is to enter the login and password for the corresponding network. The fields for this are highlighted in Figure 10.

If you are connecting to the network for the first time, you will have to create this data, after which the server will check it and, if it matches, “allow” it to enter the network, and you will be able to use it immediately.

If the connection is not happening for the first time, the server will not check them, but will immediately “let them” into the network.

After entering the appropriate data, you just need to click the “Connect” button.

Next, a window will appear asking you to connect to the connected network right now. But it’s better to close this window by clicking on the corresponding button highlighted in Figure 11.

Now the setup is complete and all that remains is to connect to the created network. To do this, you need to go to the “Network and Sharing Center” again.

In the window that opens, select the “Connect to network” item, highlighted in Figure 12.

In it, all you have to do is select the created connection and click the button highlighted in the same figure.

So, we already know how to set up a VPN connection on Windows 7.

As for Windows 10, the algorithm of actions is almost the same. Only some interface elements and access paths to them may differ.

For example, “Network and Sharing Center” looks almost the same as in Windows 7.

Moreover, there is a very similar item called “Creating and setting up a new connection or network.”

In the future, the setup steps are almost the same, only the interface will be slightly different.

Inconveniences may only occur for those Windows 10 users who do not use the so-called classic view, but the “Control Panel - Home Page” view; you will first need to go to the “Network and Internet” section, and then select “View network status and tasks” "

In any case, there is absolutely nothing complicated in the setup procedure and there cannot be. Interestingly, a VPN connection can be used even on Android devices.