[Openswan Users] How to setup a VPN server compatible to "IPSec VPN" on iPhone?

[yegle]

Hi everyone

I'm looking for a detailed guide which allows me to setup a VPN
server, and I can connect it using iPhone's "IPSec VPN" option.

On iPhone, this VPN is named "IPSec" and has a Cisco logo on the
screen. I'm told that this is called "Cisco IPSec VPN".

I've setup an L2TP/IPsec VPN now and want to try something new. Hope
someone can give me a hint. Thank you :-)