> The Monowall exposes my internal ip adress (NAT address). A security risk?
Unless you did some major modifications to your default m0n0
installation (advanced routing, etc), I don't think m0n0wall's the
thing that's exposing your internal NAT address. You're probably
noticing it from your application level, where some applications
enclose the detected IP at the application layer.
IMHO, for the most part, if it is a private IP range (not internet
routable), exposing it to the outside world usually isn't going to be
much of a security risk. Although, I'm sure for a determined attacker
just knowing your external IP is enough to wreak havoc.