Support Center / General information / What is OpenVPN?

What is OpenVPN?

OpenVPN is a VPN protocol. A VPN protocol, or a “tunneling protocol,” is the set of instructions your device uses to negotiate the secure encrypted connection that forms the network between your computer and another. 

OpenVPN uses SSL/TLS to handle its key exchange, has no known vulnerabilities, supports Perfect Forward Secrecy, and is very stable. It also supports both UDP and TCP.

OpenVPN is widely considered to be one of the most secure VPN software solutions. It is also open-source, which means that anyone can verify its code or use it for free. You can read more about how OpenVPN compares to other VPN protocols on our blog post, Which VPN protocol is the best?

OpenVPN is available in all Proton VPN apps. 

  • Windows: OpenVPN
  • macOS: OpenVPN and IKEv2
  • Android: OpenVPN and IKEv2
  • iOS/iPadOS: OpenVPN and IKEv2
  • Linux: OpenVPN

If you are encountering connections problems, it is often useful to change VPN protocols. Our Windows, macOS, Android, and iOS/iPadOS apps support Smart Protocol, an anti-censorship feature that intelligently probes networks to discover the best VPN protocol configuration required for optimal performance or to bypass censorship.

For example, it can automatically switch from IKEv2 to OpenVPN, or OpenVPN UDP to OpenVPN TCP, using different ports as required.

Learn how to change VPN protocols or select Smart Protocol

Related questions

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How do I change VPN protocols?

Does Proton VPN have bandwidth limit?

DNS leaks and how they compromise your privacy.

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  1. Evan

    Every time I try to quick connect there’s either a message that pops up saying “Maximum connection reached” or it doesn’t do anything at all. Why cant I connect?

  2. ProtonVPN Team

    Hello Evan, please contact our customer support team with the connection logs, or just simply submit report a bug and we will look in to where the issue is.

  3. Mokhry

    Does ProtonVPN free version,or any other,bypass the ISP?My Wi-Fi connection still shows my ISP as the default connection and ProtonVPN is functioning on the control panel.How does it work,if it has that capability?

  4. ProtonVPN Team

    Hello. Any VPN that is connected on your device will cover all of your device internet traffic and encrypt it. “Bypassing” has many meanings in your question, but to clarify, VPN is not an internet provider, and it does not change the ISP. You still have to have the internet from ISP to be able to connect and maintain the VPN connection. Nonetheless, the ISP does not see any of your internet activity while connected to the VPN, since the traffic is encrypted.

  5. cheech

    trying to connect with iphone and ipad need detailed setup i am using open vpn app downloaded client keeps saying failed

  6. ProtonVPN Team

    Hello Cheech, please provide more detailed information on like what error message exactly do you get, what server are you trying to connect to and what credentials are you using to our support –

  7. mellifluous

    Please add support for the GLInet Shadow router (as I currently have with TorGuard). [AR-300M] Three cheers for Atheros.

    It helps secure privacy on campus networks

    One up TorGuard and support the new GLi net usb to ehternet [openvpn]

    Secure my campus connection from a workstation without “tampering” with the ethernet cable

  8. ProtonVPN Team

    Thank you for the suggestions, we will see what we can do about it!

  9. Flo

    yes please support the GL.iNET Routers (e.g. the GL-AR150)
    Thanks in advance,

  10. Rik

    I currently have PIA for my home network VPN utilized through pfSense. I would like to switch to ProtonVPN but only if a setup through pfSense is supported. Is this in the works?

  11. ProtonVPN Team

    Hello Rik,

    We are currently working on adding more tutorials to our knowledge base and will surely make one for pfSense.

  12. user

    Related question: I currently use PIA for my VPN and am wondering if I can use both PIA and ProtonVPN at the same time and/or easily switch between them from my devices like my laptop and mobile. Thanks!

  13. ProtonVPN Team

    Using two VPN providers at the same time could cause some stability issues, but its different for almost every customer, so it would be the best to find out by using our free services and 7 day trial of Premium plan. 7 Day trial will activate the moment you connect for the first time with your free account.

  14. mellifluous

    +1 for pfSense configurations

    I would like both setup options for all traffic through vpn, and also how to send traffic from selected hardware (by MAC ?)

  15. Matthew

    Has anybody setup ProtonVPN using the Linksys WRT3200’s OpenVPN service? If so, any tips?

  16. ProtonVPN Team

    Hello Matthew,
    Please contact our support team with your router firmware version and we`ll do our best to help you out!

  17. John Lehman

    Instructions for how to set up on an Annonabox Pro router would also be most welcome

  18. Marcos

    What version of OpenVPN is ProtonVPN using as client version OpenVPN v2.4.3 was recently released which closed some serious vulnerabilities

  19. ProtonVPN

    We have the latest.

  20. Ben

    My torrent client requires port forwarding, I read you had P2P support, what am I missing?

  21. ProtonVPN

    we do not support port forwarding to prevent unwanted hosting from behind our vpn. However p2p traffic should work on the default ports for udp (1194) and tcp(443)

  22. mellifluous

    enable DHT

  23. tormaid

    Does ProtonVPN support port forwarding? AirVPN, VyprVPN, and several others support this feature now, and NordVPN is adding it this year. I really want to get ProtonVPN installed on my router as soon as it is available publicly, but I do require this feature.

    Any information you could provide would be extremely helpful. Thank you!

  24. ProtonVPN

    We currently do not support port forwarding for launch to prevent users from hosting prohibited content through the VPN network which would severely deteriorate the experience for other users. We’ll be sure to look at possible implementations of this in the near future. Outgoing connections are available through port 1194 on UDP and 443 for TCP.

  25. Nick

    Do you have any instructions on how to setup on a TomatoUSB router?

  26. ProtonVPN

    router guides coming in the near future, stay tuned

  27. RC

    I am interested in the Tomato instructions as well. Could you also include instructions for popular NAS devices as well, such as Synology?

  28. Amadeus

    Yes, an official router recommendation would be great! Right now I am looking into OpenWRT.

  29. mellifluous

    OpenWRT lives on these handy portable devices
    wireline speed might be limited by processing power.

    Support open source hardware.

    More powerful Atheros option is slightly more costly

  30. Amadeus

    For OpenWRT (and LEDE) can I say LinkSys WRT1900ACS is 100% open source friendly and it is intended to have its firmware replaced with 3rd party firmwares.

    You may feel it is expensive, but with anything you get what you pay for.

  31. mellifluous

    others might want to think twice

Comments are closed.

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