OpenVPN what is it and how to use it

What is OpenVPN?

OpenVPN is a protocol for implementing a VPN that provides both point-to-point and server-to-client connections. It was introduced in March 2002 as an open-source product and is regularly improved. It is based on SSL/TLS technologies with libraries like OpenSSL/PolarSSL, and UDP and TCP transport layer protocols are used for data transfer (the second is considered a bit more stable, and with the first higher speed, which makes it preferable). With OpenVPN, you can bypass the firewall and NAT, and it is almost impossible to detect and block because it is indistinguishable from normal HTTPS traffic. Because of all this, it has become one of the most popular solutions - not without reason VPN providers offer it in many default pricing plans.

What are the advantages of OpenVPN?

Before telling you how to install OpenVPN, how to use it and how to configure it, it is worth understanding why we should do it at all. Therefore, we must point out the main advantages of this technology:

• Highest security. OpenVPN uses 256-bit encryption keys, which is enough to protect your information. And if this is not enough, you can add the algorithms Camellia, Blowfish, AES, and several others. Plus it supports DHCP, dynamic IP, any port settings, etc. Independent audits have found only a couple of problems, and they have already been fixed.
• Authentication flexibility. Authenticated connections can follow different scenarios: pre-set key check, via familiar username/password, certificate authentication. And do not forget that it is open-source, that's why there are a lot of plugins and scripts that can make this procedure even more reliable and convenient.
• Additional security. The functionality of the protocol - thoughtful in many sometimes not obvious nuances. For example, OpenVPN has protection against flooding or port scans and DoS attacks (this is fixed by verification through HMAC). There are also root level restrictions for revoked certificates and privilege resetting - to name a few.
• Cross-platform. Unlike some analogs, the protocol in question is supported by almost all operating systems: Windows, Linux, macOS, FreeBSD, OpenBSD, NetBSD, QNX, and Solaris, as well as Android and iOS. Therefore, the answer to the question of what is OpenVPN is probably of interest to everyone who goes online - no matter what device is used.

How do I install OpenVPN?

Separately, it is worth mentioning that OpenVPN is also easy to use. Yes, the fine manual configuration of the protocol may seem relatively complicated, but at a basic level, everyone can handle the installation and launch of the technology. In this case, the installation principle is the same - no matter what operating system is installed on the device. The only difference will be in the interface details, but the steps themselves are identical:

1. Getting the configuration file. The first step is to choose a VPN provider, pay for his services (if it is a paid service, of course), and download configuration files for OpenVPN from his official site. They contain the necessary information to connect to a VPN server. It is required to do it once and among the files the most important with the extension .ovpn (usually their whole package is packed into one archive).
2. Installing the client. Next, the client for the service must be installed on the device. For Windows and Linux computers, it can be found on the OpenVPN website, for MacOS you will need the Tunnelblick or Viscosity applications, and for Android and iOS - the OpenVPN Connect application (the official product). You can start by confirming the "default" settings for OpenVPN, you can figure out how to use them later if necessary.
3. Import data. At this step we have to add the .ovpn file to the client. In Windows, you do this by right-clicking on the program's icon in the tray and select "Import Configuration". On MacOS, drag and drop the file onto the application icon in the menu bar. On Android, find Import in the application menu, while on iOS, go to Open in OpenVPN. And Linux will require its own command. For example, in Ubuntu it is: sudo openvpn ~/ Downloads/config.ovpn
4. Connection. The last step remaining is to run the client to communicate with the VPN server. In the gadget app, click Connect or Connected, and in Tunnelblick, for example, click Connect. In Windows, the options are many: from simply restarting the client to calling the context menu on the icon in the tray and selecting "Connect". And the confirmation will be a window with entering the login and password of the VPN provider and a pop-up message with the status of the process.

That's it, the installation is done and you know everything you need to know about OpenVPN: what it is and why it is there - so you can work in a safe environment! And if you want, you can configure autorun, UDP over TCP priority, block DNS leaks, or select the desired ports - and these are just a few examples of additional features… You can find all the details in the doc folder in the installation folder or in the Help guide on the official protocol website.

How to create a VPN server with OpenVPN?

Let's speak at once: we are not going to describe in detail the scenario of creating a secure server with this protocol. Yes, it is also an important part of the topic of what OpenVPN is, but the task of raising such a VPN server is in fact a separate topic. Its scale can impress even a trained person! We will list only a part of the required work so that you can estimate the complexity of the project:

• choose a VPS with root access, permanent IP address, and TUN/TAP driver support;
• Set up IP packet redirection in the OS kernel;
• configure the firewall;
• create the CA directories and the CA itself;
• create the server certificate, keys, and encryption file, as well as key pairs for the client;
• correct the server configuration file;
• prepare the infrastructure for the client configuration files;
• generate client configuration files using a script;

…and much more! And after all the procedures, you should test the hardware and get it up and running. Plus note: the implementation of each step is different on different server OS.

However, you can simplify such a project in some respects - if you contact HostZealot. We provide VPS for rent, which is optimally suited for various tasks, including organizing a VPN server with OpenVPN technology: they are fast and stable. In addition, we have a flexible pricing plan, as well as competent 24-hour technical support. They can always tell you how to set up a VPS or how to use OpenVPN, help with VDS monitoring - and answer any other questions!