openvpn3 VS openvpn-gui

All our products builds on what we call the "OpenVPN Core". In essence, that is the OpenVPN 2.x project and the OpenVPN 3 Core library. This is the "low level" code which provides the core VPN functionality.

OpenVPN 3 (Core) is a complete rewrite and reimplements the OpenVPN protocol as a C++ library. The OpenVPN Connect (macOS, Windows) apps and OpenVPN 3 Linux project are all based on the OpenVPN 3 Core project. In addition, the OpenVPN 3 Core can be activated instead of OpenVPN 2.x on OpenVPN for Android. Currently all of these products and projects only implements the client side.

I use OpenVPN frequently for work and the OpenVPN GUI client since forever has an annoying bug (Which is that with Windows with multiple keyboards layouts, especially Arabic, upon connecting with OpenVPN the Windows language will switch to the second rtl language) that they don't plan to fix (check this and this).

It is likely an issue with the 'cipher' options, if any, that are in your ".opvn" file. This is telling you that the opvn setting is not finding a matching cipher it is allowed to use. The fix per the message would be to add the Servers cipher to your options. https://github.com/OpenVPN/openvpn-gui/issues/381 https://github.com/OpenVPN/openvpn/blob/master/doc/man-sections/cipher-negotiation.rst

The big downside of the mobile SSL VPN solution (which is basically OpenVPN) is, you can not establish a vpn connection before the windows login. So Windows Group Policies are not applied immediatly and the user needs to manually connect to the VPN after the login. If OpenVPN would provide such a solution I would switch back to SSL VPN. There is still a feature request on Github since 2016 for this feature. See here: https://github.com/OpenVPN/openvpn-gui/issues/77

In addition we back several other open source projects, such as the OpenVPN GUI, OpenVPN for Android and OpenVPN 3 Linux ... these all provide various user interfaces on top of the OpenVPN Core component.