To ensure a specific device always receives the same IP address from a DHCP server, the administrator should configure a reservation. This ties a particular IP address to the MAC address of a network device, such as a server, ensuring it always receives the same IP address upon requesting a lease from the DHCP server. Exclusion ranges are used to prevent specific IP addresses within a scope from being assigned dynamically, but they do not tie an IP to a specific device. Scope options allow for configuration of certain settings for all clients within a scope, such as DNS servers or gateways. Lease time determines how long a client can use an IP address before needing to renew the lease.