Fix 'TLS Error: TLS handshake failed' on OpenVPN client

Solution 1:

I had this problem as well.

Am using digitalocean provider for my server and the problem was with floating ip feature.

In order to fix that, you have to update openvpn config setting:

local <ip anchor>

ip anchor should be an ip adress gathered from ip addr command, see example:

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Solution 2:

As suggested by Michael Hampton and Michal Sokolowski in the comments on my question, it was a problem with the port forwarding rule I created on my gateway. OpenVPN is configured to use UDP, and I forgot to switch from TCP to UDP on the gateway as I usually don't use that protocol. The forwarding rule now uses UDP, and my VPN is functional.