Is it possible to use Microsoft's "Secure Connection Rules" (IPSec) with VPN?

Is it possible to use Microsoft's "Secure Connection Rules" to authenticate/encrypt connections while using VPN at the same time?
What are the configurations necessary?

It should look like this:

Client A <-- VPN --> VPN Gateway <-- LAN --> Client B
  FTPd   <------------- IPSec ------------->   FTP

(I know there are other ways to secure FTP, I just use it for testing)

Thanks


Update 1:

To clarify the objectives:

  1. Traffic in the LAN should be authenticated and have integrity, but should not be encrypted (because of the IDS)
  2. Traffic passing the internet or other strange networks should have confidentiality

Solution 1:

IPSec policies are applied based on source/destination addresses, so they should just not care about where the traffic is actually flowing; so, yes, applying them to computers whose communications happens via a VPN should work.

But why would you need such a thing, when you can encrypt the VPN itself?


Edit:

In order for IPSec to work, some traffic needs to flow between the involved machines:

  • UDP port 500
  • UDP port 88 (if you're using Kerberos authentication)
  • IP protocols 50 and 51

More info here.

I don't know if this can be achieved through a VPN... the low-level IP protocols look very much like a possible problem here.