Quando eu tento instalar o vpn, recebo isso:
root@root:~# apt-get install network-manager-openvpn-gnome
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package network-manager-openvpn-gnome is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'network-manager-openvpn-gnome' has no installation candidate
root@root:~#
O pacote network-manager-openvpn-gnome está no repositório Universo do Ubuntu.
Habilite este repositório primeiro.
Em seguida, instale usando
sudo apt-get install network-manager-openvpn-gnome
Sugestão extra, não seja root. Use sudo sempre que possível.