If your upstream DHCP server is dnsmasq, it can be configured to assign addresses via mac address to make servers on DHCP feasible.
Server ( Static IP) ====
For servers, the [[Funtoo Linux Networking]] scripts are recommended. They are optimized for static configurations and things like virtual ethernet bridging for virtualization setups. See [[Funtoo Linux Networking]] for information on how to use Funtoo Linux's template-based network configuration system.