Ok, there is an option to set in your DNS configuration file to allow
for DDNS (Dynamic DNS) which will allow you to add addresses issued
from DHCP. I forget the name of the statement and options as I
haven't done this for a few years, but I remember doing it. You can
also reserve a block of addresses in your DHCP conf file, or exclude a
block.

This is easy, I just don't feel like doing a man on the DNS and DHCP
conf files right now.