What is happening is that the PAT on your wan interface is changing the source ports from the VPN client. This is breaking the IKE/IPSEC negotiation.
What you probably need to do is use NAT-T which add a UDP header to the IPSEC packets. I've attached a link that explains what it is and how to enable it on a Cisco client (don't know if thats what you are using but all vpn clients should support it ).
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...