ipsec and ipnat

[Arthur Thomas <ascpb_(_at_)_bigfoot_(_dot_)_com>]

greetings

currently i have my network setup like this :

(internet) <->  (firewall/ipnat) <-> (mail/web/shell servers)

i have only one ip address so the firewall is redirecting ports for the
mail and web servers. it is also providing nat so the servers and
workstations behind it can get out to the internet.

i would like to set up IPSec between this network and another. I have a
question about the port forwarding. If I can connect to the firewall box
via IPSec, is my email and web browsing to that site going over IPSec
too (it is redirected to machines behind the firewall). I'm really
concerened with encrypting the data that goes over
the internet. I'm looking to try and encrypt it up to the point where it
reaches the firewalls of each site.

i'm worried that IPSec will only work if I talk to the firewall box on
non-redirected ports.

arthur