What should you do to ensure that DHCP does not assign the addresses you have statically assigned to the network servers?

Simple assign the range in the DHCP Server after excluding some IPs For the Network Server(s).

But if suppose you have already assigned the range and want to configure a static IP for the server in that range only, then just add the exclusion range in DHCP that you don't want DHCP to use for distribution. Exclusion range can be of one IP also.

Hope this helped

-- By MyNarutoAnime