What's required to configure VPN (over IPsec) server with FreeBSD which can accept connections from iPhone? As I guess, the server should have ability to manage incoming connections, but I don't know to do that. And how to integrate the management system with VPN?
Alternatively, you can go the old way of using a dedicated L2TP daemon. I found a link to a lousy article on setting up FreeBSD for iPhone VPN connections. It seems to be current enough that it would work, most of these older L2TP daemon projects are abandoned at this point though.
Basically you need:
Other parts/layers are optional and will depend on your exact situation.