In environments where new workstations may be added on a regular basis, maintaining a consistent set of HOSTS files may require an unacceptable overhead (see HOSTS File). In such cases, a centralized name resolution system is preferable. This is normally provided by one or more designated systems (often domain controllers), and is frequently termed DNS. The assignment of IPs to workstation network interfaces can still be performed statically, or can be dynamically assigned.
Dynamic IP assignment refers to the ability of a designated system to dynamically assign an IP address from a pool of IP addresses, for a workstation connected to it. For robustness, SCADA systems are generally configured with static IP address assignments, reserving dynamic IP assignment for multiple dial-in links.