Still, what are you trying to do. Sorry, I don't understand.
Do you want to use one dedicated machine as firewall / NAT translator and use DHCP for your internal (home) network? That machine will then have 2 NICs, one connected to Internet and one to your home network. Then every machine on your home network will get a dynamic IP-address from that machine and they can all access the Internet through the NAT firewall making your home network reasonably secure.
What Linux distribution are you using? If you want to know what distribution to use on a machine that does the above, then I'd recommend Devil Linux: