OpenVPN Support Forum

HI,

I work for 1 month on an entreprise and I have to do a vpn with pfsense and oVPN but when I finished, I have this error message on the openVPN-GUI (failed to negotiate cipher with server. Add the server's cipher ('AES-128-CBC') to --data-ciphers (currently 'AES-128-GCM') if you want to connect to this server.) and Idk how resolve this problem.

thanks if you reply.

(And sorry for my english, I'm french and I have difficult on english..)

No worries about your English! I understand the struggle. Regarding the error message you're encountering, it seems to be related to a cipher mismatch between the server and your OpenVPN client. To resolve this, you can try adding the server's cipher ('AES-128-CBC') to the --data-ciphers option in your OpenVPN configuration file. This should align the cipher settings and allow you to connect successfully.

Also, I think you might find more useful info in this GitHub thread: https://github.com/OpenVPN/openvpn-gui/issues/381

okay thanks I tried and It's work,
thanks you !