As these kind of questions pop up regulary in the support forum, eventually it could be worth to discuss if in a future release more VPN protocols should be supported.
Currently (3.9.3) there are those two support:
OpenVPN
Cisco; Cisco means the “old” Protocol used by Cisco PIX, which is essentially IPsec. Can be used to connect to many different IPsec capable gateways like AVM or Lancom.
However, there are a few other protocols which are even at least as popular:
L2TP; Used for example by Dell UTM; Debian has network-manager-l2tp and network-manager-l2tp-gnome to support it.
Cisco Anyconnect; The “newer” Cisco protocol, which is essentially SSL VPN; used not only by Cisco but also Juniper and some VPN services; Debian has openconnect to support it.
Don’t forget wireguard! As the person who got OpenVPN added back in the day I think a lot of this would need to be analysed wrt. advancing the mission but certainly for me as a non target user easier wireguard would be helpful.
Thanks Nick. I think we support wireguard through NetworkManager in our stable releases. It looks like there is no GNOME GUI for this available though, not even in Debian testing.
@egrath we’d support adding l2tp and anyconnect support, feel free to make a pull request if you have some time!