hi,
i am not certain that i undertand what you have done.
but i would try something like this;
set your server to have dynamic ip, then
set ebox to give a static IP to each server.
you can do this by getting each server MAC address
you should have at least two interface correctly configured - 1 internal and 1 external.
you would also need a DNS for your internal network alread setup (eg: mynet.lan)
on eBox, click on DHCP and choose your internal interface from the drop-down list.
setup the common-options details
setup a new range for this interface (leave some room for the static IPs that you will give to your servers)
then add fixed addresses, for your servers, you will need;
name = normally the DNS name of this machine
MAC address = the value from your server interface
IP address = IP address that is used by DNS to find this machine
NOTE: DNS and DHCP work very closely together - make sure that you use the same IP values on both.
let me know if this is what you are looking for.
Nicolas