The setup you describe is not a wise move. Replicating the outside network through your 'server' doesn't really help you much, is complicated, and expands your security concerns.
What you should be thinking of is having your 'server' be a firewall to your inside
'Server eth0' ip given by CB
'Server eth1' ip # in private range
all of your gear
In this approach you set up your inside network as a private non-routing IP range (192.168.0.0/255.255.255.0 for example), serve up DHCP to all your boxes behind through eth1 and have your server box set up as a router for all packets inside to CB and the WWW.
- You then run a tight iptable/netfilter firewall on eth0 to help protect everything behind.
- You run DHCP from 'Server eth1' for your other gear.
- You are essentially running your own network and can do what you like inside.
There is a great deal of information about this on the web or folks here can help you with the various portions of the setup...