[strongSwan] config of external single server accessible from linux, windows and android l2tp/IPsec client

[Maximilian Renkin]

I have to configure a single server (placed at a hosting provider) which should 
be accessible via l2tp/ipsec (android 2.2, linux, windows7 clients) and 
provide some services like version management, issue tracking etc.
My knowledge in that topic is rather weak.

Is there a simple, but complete howto available describing all steps to get 
such a system ready to access or can anybody share such a probably not so 
exotic configuration?

Thanks in advance

Max Renkin