what is OpenVPN? How does it work?

IF you care about your online privacy and are interested in encrypting your information on the web so hackers can not take advantage of your information. In that case, You are most likely using a VPN. VPNs have their proprietary protocol, and the protocol of each VPN is its main element; protocols include a set of rules from how to securely connect applications to the server to methods of data transfer.

Most VPNs support several secure IKEv2, L2TP, and SSTP protocols, of which OpenVPN is the most popular and the best protocol. Open VPN is an OpenSource connection protocol that, by creating a secure tunnel between two points in the network, Increases security and makes the connection easy. Many private companies and VPNs use this reliable technology to transmit their data encrypted and privately over the Internet. Surely you have heard the name OpenVPN many times and are familiar with it because it is currently the most popular and widely known protocol globally.

In the following, we want to introduce you to the most popular VPN in the world and what is OpenVPN? What protocols does it have? How does it work? And why is it so popular among Internet users?

What Is A VPN Meaning?

A VPN (Virtual Private Network) connects you to a private Internet network that is limited to you, rather than directly entering a crowded and insecure Internet space.

About VPN Protocols

A VPN protocol is a set of instructions that your device uses to establish a secure connection (network between your device and another computer); VPN protocols represent the processes and instructions of VPN providers to ensure that VPN users have stable and secure communication between the VPN server and themselves.

Different protocols of VPN normally include the following:

1) PPTP (Point To Point Tunneling Protocol)

2) L2TP/IPSec (Layer 2 Tunneling Protocol)

3) IKEV2

4) SSTP (Secure Socket Tunneling Protocol)

What is OpenVPN?

OpenVPN is a standard security technology used to establish secure connections as a connection protocol in a VPN. It is also the software used to establish point-to-point and site-to-site communication on a virtual private network.

This popular protocol and software was released by James Yonan in 2001 and is one of the main elements and protocols in VPN; OpenVPN software and protocol are provided as open-source and support up to 256-bit encryption; Being open-source has many advantages, one of the most important of which is that due to the access of all people to its structure and source code, when security vulnerabilities and problems occur; A community of VPN programmers and developers support users in troubleshooting, constantly testing, updating, and improving the protocol.

OpenVPN relies on SSL / TLS to authenticate and encrypt information, unlike other tunneling protocols that are based on IPSec; As you know, SSL / TLS is the same protocol used to protect HTTPS websites, and when you rely on it in your cryptographic system; This means that all of these web servers indirectly support you. SSL to protect financial transactions, data transfers, emails, and other things is very popular; It can also bypass firewalls and Network Address Translator (NAT).

The OpenVPN protocol takes advantage of SSL / TLS features in various contexts; For example, you can confirm the connection to a legitimate server and create encryption keys to protect your data, and you can check your data.

Openvpn is available for free as a protocol and the main element of VPN, but the possibility of using its free services is limited. After several times of connections ( usually two times), you will have to buy its VPN service; Of course, there is a point that you can also buy VPS to create a VPN Server using VPS.

Implementing proper encryption is usually not easy on a modern web platform, but in OpenVPN, it will not require effort, And the OpenSSL library is responsible for encryption. OpenVPN uses the OpenSSL library to support any encryption system or hash function and common public and private key generation technologies such as AES, Chacha20, Poly1305, Triple DES, SM4, MD5, SHA-2, SHA-3, BLAKE2, Whirlpool, RSA, Uses Diffie-Hellman, Elliptic, etc.

OpenVPN flexibility is one of its significant advantages over competitors’ encrypted protocols; by this feature to create maximum reliability, it can set up its encryption tunnel based on TCP (Transmission Control Protocol) protocol or increase the encryption speed based on UDP (User Datagram Protocol).

One of the advantages of OpenVPN is its compatibility with all major operating systems such as Windows, Android, Linux, Mac, and IOS. This protocol offers powerful encryption standards and is an excellent option for breaking geographical restrictions.

Where did the OpenVPN story begin?

James Yonan was a developer who traveled to Central Asia and needed to connect remotely to his business office. He had to establish an unencrypted connection through unknown servers in various countries. James Yonan had to develop poor security practices for Using this connection. So he realized the vulnerability of his data and decided to create an open-source project called OpenVPN to encrypt the data and protect it from hackers and strangers.

How does Open VPN work?

In simpler terms, OpenVPN is a creator of a private connection or tunnel between the user and the VPN server that runs in client-server mode. This means that there is an OpenVPN server that is connected to the Internet, and OpenVPN clients are connected to the server and have full Internet access from there; When connected to a server, the client uses the server to Control all Internet traffic; This means that the client looks like a server. Also, the traffic that passes through it is fully protected by encryption, and ultimately your data is protected against ISPs or Internet Service Providers, hackers, and third parties.

Generally, Any activity we do on the Internet is sent to the webserver by a packet containing our request and data.OpenVPN encrypts these packets using the software on our computer and then sends the packet to the OpenVPN server. OpenVPN decrypts the packet forwarded by our device using specially defined keys and then sends the packet to Google Web Server, and the exact steps are repeated when Google Web Server responds to our request; This means that the package is first received by OpenVPN and then sent to our device after encryption, and therefore all of the information Are encrypted and They cannot be stolen and they transmitted in a secure tunnel.


As we explained, the OpenVPN protocol uses the OpenSSL library specifically for authentication and encryption; It also uses UDP or TCP to transfer data online. TCP is more stable because it offers error correction features in that it waits for confirmation when sending a packet before resending or sending a new packet. It is more reliable, but UDP does not perform error correction. Despite being less stable, TCP has a higher transfer speed. According to research, OpenVPN usually performs better on the UDP platform, so OpenVPN Access Server first tries to communicate via UD. The server will try to establish TCP connections only if this connection fails. Most VPN providers also offer OpenVPN over UDP by default.

OpenVPN is very compatible when it comes to network settings. You can also use other programs, scripts, and plugins to improve OpenVPN’s performance. All this makes the protocol more flexible and powerful.

OpenVPN encryption

OpenVPN implements 256-bit encryption as standard, meaning that its keys range from 256 to zero and one that makes them very difficult to guess or break. Interestingly, OpenVPN supports other more powerful ciphers such as 3DES, lowfish, CAST-128, or AES.

The protocol also uses an additional encryption feature called Perfect Forward Secrecy (PFS). In this method, a new key is created with each connection, which ruins the hackers’ dream of accessing your information by offering different password codes and encryption methods.By creating a new key each time you connect, this method has made things difficult for thieves.

Benefits of OpenVPN

OpenVPN has many advantages and features that make it the most popular protocol globally compared to its competitors. In the following, we will mention its benefits.

  1. high security

The main purpose of this protocol is to create a secure and confidential tunnel to transfer data and protect your information against unknown people; The program uses strong 256-bit encryption and several layers of security such as predictive keys and peer authentication to increase data transfer security. As well as creating unique keys in each section and with each New connectivity and even the use of OpenSSL on the network have been effective in protecting data by authenticating HMAC packets. These factors make it almost impossible for cyber-attacks to misuse and steal your personal information.

  1. Support for all operating systems

One of the best features of OpenVPN is the ability to install this program on all common mobile and desktop operating systems; It even supports lesser-known operating systems such as OpenBSD, FreeBSD, and Solaris.

  1. Free and opensource

Free installation and Download of OpenVPN software on all operating systems is one of the admirable advantages of this program. Additionally, you can connect to a VPN server for free by using OpenVPN.

One of the strengths of OpenVPN is it’s open-source, Which means that anyone can access the source code and download it and troubleshoot it; Also add features to it. This advantage of OpenVPN has helped a lot in developing and expanding this software and has made it a strong and reliable project for users and organizations.

Note: Two connections of OpenVPN are available for free then you will have to pay to buy a VPN.

  1. Ability to control connections

Unlike other protocols, OpenVPN gives you the freedom to choose between TCP and UDP to transfer your data. You will have more control over the connections, and it will be easier to adapt them to your needs.

  1. Difficulty blocking connections

It is tough to detect and block OpenVPN connections due to TCP and UDP ports. OpenVPN can bypass major limitations; Even if the firewall is installed over the network, it cannot block OpenVPN connections. It can easily bypass them; For example, configuring OpenVPN on port 443 deceives various firewalls.

  1. Support through the large community

OpenVPN is supported by a large community of VPN developers and programmers due to its open-source nature to quickly fix any vulnerabilities and bugs and add new technology and features tailored to web development. The existence of this growing community around the world that is debugging and reviewing source code; Increases the credibility and performance of this project.

pros of OpenVPN

Disadvantages of OpenVPN

  • Complexity

Configuring and launching OpenVPN for the first time has more difficult steps than other applications, including many instructions and configuration aspects that require expertise and technical knowledge; In the initial setup step, you should call the server file instead of selecting a server. Of course, there is professional network training on the sites for beginners that you can take advantage of them.

  • Need to install software

Although OpenVPN is compatible with all operating systems, it requires the installation of applications to use this protocol and cannot be integrated with the operating system kernel.

  • Slow connection speed

This protocol is slower than other cryptographic protocols; The slow speed of the connection is usually related to the server location and distance, and apart from this, the process of encryption and decryption in the OpenVPN user space is the reason for the increased delay; Of course, users ignore the disadvantage of this software due to its many features. To compensate for the speed of this protocol, providers and users usually try to use powerful devices, allocate more bandwidth, and have a faster internet connection; Also, if the UDP protocol is used, although some error correction steps are eliminated, the data is eliminated transfer speed will be higher.

  • Incompatibility with all proxies

Although OpenVPN is compatible with most proxies, some have difficulty connecting to the network and do not support OpenVPN.

The future of OpenVPN

OpenVPN has been at its peak for many years, and According to the experts, those are the final years of the superiority of OpenVPN to its competitors because of new protocols such as WireGuard, ExpressVPN, and NordVPN are set to replace OpenVPN.

The new protocols have a more limited platform and emphasize only the essential performance and features of the VPN; These protocols may perform faster than OpenVPN, but they have their drawbacks. For example, some of them do not work on Mac and Linux operating systems and work on specific operating systems.

Other disadvantages of the new protocols are that they are not open source and do not support both TCP and UDP protocols. So we conclude that OpenVPN, with its flexibility and features, although slower in performance than its new competitors, is still popular among users as an open and reliable encryption protocol.


TCP stands for "Transmission Control Protocol," a two-way communication protocol that enables the transmission of messages between devices on a network. TCP is the most important and widely used network communication protocol. Unlike UDP, this protocol corrects the error, and in this case, the security is higher than UDP, but due to the more process that takes place, we encounter a slow speed.

OpenVPN may not be the most user-friendly and easy-to-use protocol, and setting up a connection can be challenging.
But we will explain the connection steps briefly; The first thing you need to do to set up an OpenVPN connection is to purchase a VPN; It's interesting to know that buying a VPN is unnecessary! You can create a VPN with multiplayer access by buying the virtual server.

After purchasing a VPN, the first thing to do is download the configuration files, which you can access and download to the server configuration files to find out how to connect to the server. After downloading the files, you need to install the OpenVPN software on your device. Run the installation file, and accept the default options.
After installing and running OpenVPN, drag the server files you downloaded in the previous step into the OpenVPN software. After this, the server is added to the software. Enter your VPN username and password.
To connect to the server, click on the OVPN files in the OpenVPN application and wait for them to connect. You will receive a desktop notification to let you know that the connection was successful.

The main reason for using the OpenVPN protocol is that it is very secure and stable and runs on multiple operating systems. Most security experts recommend that you always use OpenVPN for online activities, Especially since this option is valid because it is open source.


OpenVPN is the most popular open-source security protocol and software developed to increase the security and protection of users’ information when communicating. Its capabilities, such as encryption, the OpenSSL library, and compatibility with all operating systems, are the best choice among VPN protocols.

We have tried to acquaint you with OpenVPN in presenting this content and examining this protocol from different aspects. If you have any questions or ambiguities in this regard, please share them with us in the comments section.

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