Ok, I'm sourt of confussed, I have a cable connection, my External IP is assigned by the Cable company using DHCP, and I assigne addresses in the House via DHCP to include all the DNS stuff. My internal DHCP server assignes the the my internal IP of my gatway to all the internal IP's as both the Primary DNS, and Gateway. It all works fine. If I was not doing DHCP from the gateway box then that may be an issue.
So you guys with this problem are not useing the eBox as your Network Gateway? or you Not useing it to assigne IP via DHCP?
If that is the case then you have to manually input your DNS and Gateway in to your DHCP Server, or your systems directily. My cable IP changes about once to twice a year, so if your's is similar then the work is not too bad. I have over 20 systems in the house and use DHCP so that I don't go crazy....
-jeff