The question is: Why L2TP? L2TP on it's own is useless, because there is no encryption. Therefore L2TP is combined with IPsec. Namely IPsec with IKEv1. IKEv1 was not designed for remote access. IKEv1 does not offer user authentication, it does not offer IP configuration. That's where L2TP comes into play. L2TP uses PPP, PPP brings user authentication and IPCP (IP configuration). The other way was to use proprietary extensions like XAUTH and Mode_config. IKEv1 is old, IKEv2 is the more modern version, it comes with native user authentication and config mode. So the alternative is using IKEv2 instead of IKEv1, there is no need of L2TP. This is the way the Secure Client works. Indeed, Cisco could support IKEv2 with OS-native clients. But what is the future of the MX? The future brings the Catalyst 8000 series router. I think they will superseed the MX. The Catalyst 8000 will come with Flex VPN and SSL VPN support
... View more