Setup openvpn in Ubuntu 15.10 tested using ibvpn.com and openvpn

sudo apt-get install openvpn easy-rsa network-manager-openvpn-gnome

goto http://www.ibvpn.com

setup a free account

extract openvpn.tgz where you want

On UbuntuGnome goto settings->network->add
select vpn->Import from file

Select ibVPN-US-Dallas.ovpn

Type your email
Get the password from the ibvpn website, this is not you ibvpn account password.

Select Add.
And try it out.