What Is OpenVPN & How Does OpenVPN Work?

Last Updated: June 2, 2021

Virtual Private Networks (VPNs) are no longer strange tools to many people on the internet. They are the perfect tools for streaming content that has been restricted to specific locations. They provide much-needed privacy and secure connections for data transfers.

One thing that makes it possible for VPNs to function as they do is a VPN protocol. A VPN protocol can be seen as a set of rules or guidelines a VPN follows in its functionality.

VPN protocols are responsible for several features like security, speed, stability, and privacy. There are so many of them in use these days. Some of these protocols date back to the 90s, but with new technology comes improvements in VPN protocols.

Today, we’ll be looking at one of the VPN protocols, OpenVPN, to give you a clear understanding of exactly what it is, how it functions, and what separates it from other protocols too. So let’s begin; what is OpenVPN after all?

What Is OpenVPN?

OpenVPN protocol is one of the most secure protocols available today. It doubles as both a VPN protocol, as well as software. OpenVPN uses various security techniques to provide a secure point-to-point or site-to-site network connection. Today, this protocol is used by many VPN providers and users.

OpenVPN was developed by James Yohan and released to the public in 2001. It was designed as an open-source VPN (one of the few available currently), and it allows you to use various ports and encryption types. You can also scrutinize its source code for vulnerabilities or use it for other projects.

This protocol handles client-server communications perfectly. Simply put, it establishes a highly secure tunnel for data transmission from your end to the VPN server and vice versa. OpenVPN is available on several platforms, including iOS, Android, macOS, Windows, Linux, and routers.

OpenVPN provides top-notch security thanks to its custom protocol that uses OpenSSL. Equipped with AES 256-bit key encryption, 2048-bit RSA authentication, and a 160-bit SHA hash algorithm, hackers and other malicious parties would find it very difficult to hack your traffic.

Users love OpenVPN for streaming and accessing other geo-blocked content because it does the job perfectly without being detected or blocked. This is because the VPN protocol uses various connection ports that disguise the VPN connection as a typical internet connection.

OpenVPN also provides you with high-speed connections that are faster than other protocols. It is not the fastest on the market, but you sure won’t be experiencing lags. The speed of this protocol depends on your device and configuration.

If you’re wondering how exactly this VPN protocol works, stick with us; we’ll be talking about that in a bit.

How Does OpenVPN Work?

As we said, the OpenVPN protocol is responsible for secure end-to-end connections. As simple as this sounds, there are several necessary tools and methods that the VPN protocol implements.

To implement the appropriate encryption and authentication, OpenVPN uses the OpenSSL library. And then, it uses UDP or TCP for data transmission. User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) are transport layer protocols that handle all your data online through the VPN.

TCP requires confirmation when you send a data packet in case of an error or when you’re sending a new packet. Its error correction features give it very high stability but less speed. Meanwhile, UDP is not as stable because it doesn’t have error correction features, but it transmits data faster.

According to OpenVPN’s website, the protocol performs excellently over UDP, so the server initially attempts to establish UDP connections. It is only when UDP connections fail that the server now attempts to create TCP connections. Most VPN providers use OpenVPN over UDP as their default connection, but depending on the service you’re subscribed to, you could change it.

OpenVPN uses AES 256-bit encryption, which has proven to be solid so far. The protocol further enhances the security of your network connection with OpenSSL, Camellia, CAST-128, 3DES, and Blowfish ciphers. However, the protocol doesn’t support IPsec, L2TP, or PPTP. Instead, it implements its unique protocol using SSL and TLS.

OpenVPN uses tls-auth for HMAC signature verification to protect users from DDoS attacks, port flooding, and port scanning. And when deemed necessary, the protocol can run in a chroot jail dedicated to CRL. The VPN protocol is run in userspace rather than kernel space.

Advantages of OpenVPN

OpenVPN is among the best VPN protocols available. Its capabilities give users a ton of advantages. Some of these advantages include:

1. Security Levels: OpenVPN is recognized as a very secure protocol. It uses 256-bit encryption keys as well as some of the best ciphers that have been developed. When you use this protocol or a VPN that is equipped with it, your security is guaranteed.

2. Port Options: This protocol uses several ports as well as TCP and UDP. This gives you the ability to manage and control your connections as you’d like without limiting you to a specific choice.

3. Efficiency: OpenVPN’s port options give you the ability to bypass firewalls easily. This is an advantage in cases of serious geo-restrictions or censorship. Other VPN protocols may bypass firewalls, but they could be detected and blocked. However, this isn’t the case with OpenVPN.

4. Multi-platform support: Several VPN protocols may be highly effective, but they are limited to a few platforms. However, OpenVPN is supported on several platforms such as Windows, iOS, Android, MacOS, Linux, OpenBSD, NetBSD, Solaris, and routers. This is one reason several VPN providers use the protocol.

Disadvantages of OpenVPN

To be honest, it’s pretty tricky to find a disadvantage with OpenVPN protocol, but like everything, it is not perfect. Some of the cons of using OpenVPN include: 

1. Setup: Setting up VPN applications that use OpenVPN protocol is an easy process, depending on the service provider. However, when it comes to manually setting it up, you could face some difficulties, especially if you’re not familiar with VPN protocols or no setup instructions.

2. Speed: OpenVPN is a very secure VPN protocol without a doubt, and it uses some of the best encryption types. However, its strong encryption could affect your connection speeds negatively, causing unexpected slow connections.

3. Free Service: OpenVPN on its own is a free service. In cybersecurity, it is almost known for a fact that using a free service for your connection is very risky for a lot of reasons, such as logging your personal data, spyware, and others. 

OpenVPN Versus Other VPN Protocols

As it stands, there is hardly any VPN protocol that ranks better than OpenVPN. Only WireGuard and SoftEther come close in comparison. Let’s take a look at some of these common comparisons.

OpenVPN vs. WireGuard

Both OpenVPN and WireGuard are top-tier protocols. OpenVPN uses the OpenSSL library to facilitate various cryptographic algorithms that you could switch, such as AES-256 and Camellia. On the other hand, you can’t change WireGuard’s more modern algorithms. According to the developers, users cannot change the algorithms to avoid wrong configurations that could leave them exposed to security risks.

In terms of speed, WireGuard is the better VPN protocol. It was designed with a lighter code that doesn’t take up too much CPU power to work.

OpenVPN vs. SoftEther

OpenVPN ties with SoftEther when it comes to security. Not only are they both open-source protocols, but they also use top-grade encryption like AES 256-bit encryption and also use SSL 3.0. However, OpenVPN is more trusted because it has been around longer than SoftEther.

SoftEther offers faster network connections than OpenVPN. The developers of SoftEther suggest that the protocol is about 13 times faster than OpenVPN.

Both protocols are available on several mainstream platforms, but OpenVPN has a more complicated setup than SoftEther. However, one significant factor that sets OpenVPN protocol apart is that you may not need to download additional software when using a VPN service that offers an OpenVPN connection. With SoftEther, it’s compulsory to download additional software.

Both VPN protocols can run on their servers, but SoftEther servers can run other protocols like IPSec, L2TP/IPSec, SSTP, and even the OpenVPN protocol. Meanwhile, OpenVPN is limited to its custom protocol.

OpenVPN vs. IKEv2/IPSec

IKEv2 is another secure VPN protocol that is often compared to OpenVPN. One difference between the two lies in data security. OpenVPN provides security at the transport level, using TLS/SSL, while IKEv2 security is at the IP level.

OpenVPN is supported on several platforms, but IKEv2 is built into BlackBerry devices. Also, IKEv2 provides more stable network connections, and in case of network fluctuations, it quickly reconnects. IKEv2 is also capable of handling your network changes without you losing your connection.

IKEv2 uses UDP port 500, which firewalls can easily block, unlike port 443 that OpenVPN uses.

Conclusion

OpenVPN is available as a VPN software, as well as an open-source VPN protocol. It facilitates secured end-to-end communications and uses military-grade encryption. It is supported on many platforms. If you’re not very familiar with VPN protocols, you should avoid trying to set up OpenVPN manually.