Hi Lorenzo,
I remember about the inability to have more than one IPSec roadwarrior client on the same NATted network. I've been searching for hours but couldn't find if this is "still" a thing. The more explicit and recent article on the subject I found is this[1], which basically lowers the security of the VPN client, but should allow multiple clients in the same network to connect. I cannot make tests at the moment, I'm just investigating on possible solution, so I was wondering if someone knows more in detail how it works.
Just use IKEv2 and you won't have those NAT issues that occur with L2TP and IPsec in transport mode (although, the Windows IKEv2 client has other issues and limitations [1]).
Regards, Tobias [1] https://wiki.strongswan.org/projects/strongswan/wiki/WindowsClients
