* DHCP is a protocol that dynamically assigns IP addresses to devices on a network. DHCP allows devices to obtain an IP address automatically without manual configuration. DHCP also simplifies network management by reducing IP conflicts and address exhaustion.
* A DHCP setting is a configuration option that affects how DHCP operates on a network. DHCP settings can be applied at different levels, such as the server, the scope, or the client. DHCP settings can control various aspects of the IP address assignment process, such as the range, the duration, the options, and the exclusions.
* A DHCP reservation is a DHCP setting that assigns a specific IP address to a specific device based on its MAC address. A DHCP reservation ensures that the device always receives the same IP address from the DHCP server, even if the lease expires or the device reboots. A DHCP reservation can be useful for devices that need a consistent IP address, such as servers, printers, cameras, or gaming consoles.
* The other options are not DHCP settings that would ensure a device gets the same IP address each time it is connected to the network. Scope options are DHCP settings that apply to a group of devices within a defined range of IP addresses. Exclusion is a DHCP setting that prevents a range of IP addresses from being assigned to any device. Relay is a DHCP setting that allows a device to forward DHCP requests from one network segment to another. Pool is a DHCP setting that defines the available IP addresses that can be assigned to devices. References:
* CompTIA Network+ N10-008 Study Guide, Chapter 3: Network Operations, Section 3.3: Network Configuration Management, Subsection: DHCP, pp. 144-146.
* Professor Messer's CompTIA N10-008 Network+ Course Notes, Section 2.6: Network Addressing, Subsection: DHCP, p. 38.
* Static IP vs DHCP Reservation, The Tech Journal, May 7, 2019.