An In-Depth Look at OpenVPN

Miklos Zoltan

By Miklos Zoltan . 17 June 2024

Founder - Privacy Affairs

Alex Popa

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As a fervent advocate for online privacy and security, I have explored various VPN protocols to find the best solutions for different needs.

Among these, OpenVPN stands out as one of the most robust and versatile VPN protocols available today.

Whether you’re a tech enthusiast, a remote worker, or someone simply looking to protect their online presence, OpenVPN offers a powerful combination of security, flexibility, and performance.

In this article, I’ll delve into the details of OpenVPN, explaining its key features, how it works, and its advantages and disadvantages.

What is OpenVPN?

OpenVPN is an open-source VPN protocol that was developed by James Yonan and released in 2001.

It is designed to be highly configurable, secure, and capable of running on virtually any platform.

OpenVPN uses a custom security protocol that utilizes SSL/TLS for key exchange and supports a wide range of encryption algorithms, making it one of the most secure VPN solutions available.

Key Features of OpenVPN

1. Security:

OpenVPN is renowned for its strong security. It uses the OpenSSL library to provide encryption, supporting a variety of algorithms including AES (Advanced Encryption Standard) with 128-bit, 192-bit, or 256-bit keys.

OpenVPN can also use Perfect Forward Secrecy (PFS) to ensure that even if a session key is compromised, it cannot be used to decrypt past sessions.

2. Flexibility:

One of OpenVPN’s greatest strengths is its flexibility. It can run on multiple platforms including Windows, macOS, Linux, iOS, and Android.

Additionally, OpenVPN can be configured to use UDP or TCP ports, allowing it to bypass firewalls and network restrictions more effectively than other VPN protocols.

3. Open Source:

Being open-source, OpenVPN’s code is publicly available for scrutiny and auditing.

This transparency allows security experts to examine the code for vulnerabilities and ensures that any issues can be quickly identified and addressed.

How Does OpenVPN Work?

OpenVPN operates by creating a secure tunnel between the client and the VPN server. Here’s a step-by-step overview of how OpenVPN works:

Connection Establishment:

The client initiates a connection to the VPN server using either the UDP or TCP protocol. OpenVPN’s flexibility allows it to work on different ports, typically port 1194 for UDP.


The client and server authenticate each other using SSL/TLS certificates. This process involves the exchange of certificates and keys to establish a secure connection.


OpenVPN uses the OpenSSL library to encrypt data transmitted through the VPN tunnel. The data is encrypted on the client side and decrypted on the server side, ensuring that it remains confidential during transit.

Data Transmission:

Once the connection is established and secured, data is transmitted through the encrypted tunnel. OpenVPN supports both site-to-site and remote access configurations, making it suitable for various use cases.

Advantages of OpenVPN

1. High Security:

OpenVPN’s use of strong encryption algorithms and support for Perfect Forward Secrecy make it one of the most secure VPN protocols available.

Its open-source nature allows continuous security audits, ensuring that any vulnerabilities are promptly addressed.

2. Versatility:

OpenVPN’s ability to run on multiple platforms and its flexibility in using different ports and protocols make it highly versatile.

It can be configured to meet a wide range of needs, from securing individual devices to creating site-to-site VPNs for businesses.

3. Reliability:

OpenVPN is known for its stability and reliability.

It can maintain a secure connection even in challenging network environments and is capable of handling high levels of traffic without compromising performance.

Disadvantages of OpenVPN

1. Complex Configuration:

Compared to some other VPN protocols, OpenVPN can be more complex to set up and configure.

Users with limited technical expertise may find it challenging to navigate the various options and settings.

2. Performance Overhead:

While OpenVPN is highly secure, the encryption process can introduce some performance overhead, potentially resulting in slower connection speeds compared to less secure protocols.

However, this trade-off is often acceptable given the level of security provided.

3. Dependence on Third-Party Clients:

Although many VPN services offer custom clients that simplify the use of OpenVPN, the protocol itself relies on third-party applications for implementation.

This can sometimes lead to compatibility issues or require additional troubleshooting.

My Personal Experience with OpenVPN

In my experience, OpenVPN has been a reliable and secure choice for various applications.

I’ve used it to secure my internet connection while traveling, ensuring that my data remains protected on public Wi-Fi networks.

Setting up OpenVPN on my home router has allowed me to create a secure network environment for all my devices.

Although the initial configuration required some technical knowledge, the comprehensive documentation and support available online made the process manageable.

VPNs That Use OpenVPN

Many VPN providers support OpenVPN due to its security and versatility. Here are a few VPNs that offer excellent implementations of OpenVPN:

1. ExpressVPN:

ExpressVPN is known for its high-speed servers and robust security features.

It offers OpenVPN as one of its primary protocols, ensuring strong encryption and reliable performance.

The ExpressVPN app simplifies the use of OpenVPN, making it accessible to users of all technical levels.

ExpressVPN is one of the best VPNs around.

2. NordVPN:

NordVPN provides a comprehensive range of security features, including support for OpenVPN.

With its large server network and advanced features like Double VPN and CyberSec, NordVPN ensures secure and private internet access.

3. CyberGhost:

CyberGhost is user-friendly and supports OpenVPN across all major platforms.

It offers specialized servers for streaming, torrenting, and enhanced privacy, making it a versatile choice for different needs.

Did You Know?

OpenVPN’s Popularity: OpenVPN is one of the most widely used VPN protocols due to its balance of security, performance, and flexibility. Many commercial VPN services rely on OpenVPN to provide secure connections to their users.

Community Support: As an open-source project, OpenVPN benefits from a large community of developers and security experts who contribute to its development and maintenance. This collaborative effort ensures that OpenVPN remains at the forefront of VPN technology.

Customization: OpenVPN can be customized with various encryption algorithms, authentication methods, and network configurations, making it suitable for a wide range of applications, from personal use to enterprise-level solutions.


OpenVPN stands out as one of the most secure and versatile VPN protocols available today.

Its strong encryption, flexibility, and open-source nature make it a reliable choice for securing internet connections and protecting online privacy.

While the initial setup and configuration can be complex, the benefits of using OpenVPN far outweigh the challenges.

Whether you’re looking to secure your personal devices, set up a site-to-site VPN for your business, or simply ensure a private and safe browsing experience, OpenVPN is a robust solution that delivers on all fronts.

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