I have a box on a private network behind a couple machines doing NIS/NFS/DHCP. I'd like for this box to be able to access the interent through one of the NIS clients to download patches and such but that is it. I don't want any outside unsolicited traffic to get in. Is there a simple way to configure one of my NIS box's to do this or do i need to configure NAT? I'm currently using iptables for a firewall on all the boxes is there something I can add to iptables to forward all requests from my NIS/NFS server and then just set up a static route on my NIS/NFS server?

If anyone can share a little insight i'd be grateful.

You would need to

1. enable ip forwarding

2. setup MASQUERADING

on a system that is connected to the internet.

Check the Security forum for sample scripts. You can check the documentation at www.netfilter.org too.