To be honest I use OpenVPN quite rarely on my Android tablet, and it happens only when I need to access certain locations that tie me to a certain IP address. This type of connection could be more often used when the tabled would serve as an email reading device at a company  that would restrict email usage without a VPN.

So, today, I open my OpenVPN Connect app and try to connect. And I get this message:

Tun interface setup failed: tun_builder_error: one of ifconfig or ifconfig-ipv6 must be specified

As a good guy the first thing I do is to google the message and what I get are only stupid answers like “brackets inside the config file are wrong”. I take a look in my config file, there are absolutely no brackets. WTF!?

Looking further in the config file I realise that I changed the config on the server, so that it would use a “tap” interface instead of a “tun” one. Ok, I change that in the tablet’s config file and try to connect again. Another error message:

Sorry, but the Android VPN API doesn’t currently allow TAP-based tunnels.

WTF again!

I ended up creating a new config on the server, to make the connection on a different port, using tun-based configuration, and reversed tablet’s configuration to using tun-based interface.

And everything works! Magic!