Check firewall before connect?

[jeff.sadowski]

I had a brain fart this morning and thought about putting my outside server on my internal network.
BIG NO NO!!!!

But then remembering the reasons not to.
IE: Nothing on the internal network should be reachable from the outside. Nothing connected to the internal network should have reachable ports on the outside other then connections they specifically opened and those should only be accessible to that other side of which they initiated to.

Then I got to wondering if there was some way I could have the client vpn suite enforce this policy?
Maybe something I have openvpn run that verifys the above rules?
I can create my own package for users to install.
I'd like to be able to verify from the server that the clients are obeying the rules.
I was wondering if others have done such checking and what software they use to verify?