Is there a limitation in AWS to open an IPSec VPN connection? 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?
For me it looks to be tunnel misconfigured -  "there is a message about protocol mismatch"

Regarding the limitations quick google took me here: [strongSwan] strongswan limits