I was not saying that enabling DHCP/NAT was adding any security to the network.
I was just saying that was what I had to do to enable openbsd be the DNS server, to add 'security' (block rapidshare).
If this won't work, what else do you suggest? Someone else told me to install a proxy like squidguard...
http://forums.bsdnexus.com/viewtopic.php?id=37
but it seems like I can't add any ip to the blockings, so people here could just enter the rapidshare ip.
(which I doubt they would even do, hence their low computer knowledge)