Consider the following situation (for test purposes):
- there is a public IPSec VPN endpoint (StrongSwan);
- a machine with either Ubuntu (Strong Swan client) or Windows OS (native client) running in the cloud should be the VPN guest.
Result:
- Windows Server 2019 machine establishes VPN connection successfully but can't send any packet
- Ubuntu 18 machine establishes connection to some degree but does not create PPP0 interface.
- Ubuntu 16 machine makes a handshake but then there is a message about protocol mismatch (maybe in this specific case there is an incompatibility between both endpoints).
Are there any AWS limitations to IPSec VPN?