Which statement differentiates a reservation from a fixed-address?

• A. A reservation does not contain any client identifier.
• B. A fixed-address does not contain any client identifier.
• C. A reservation is always globally routable.
• D. A fixed-address uses DHCP options to provide custom config.

Answer: (A)

The main idea here is how identity and binding differ between DHCP reservations and DNS static mappings. A DHCP reservation is a DHCP binding that guarantees a specific IP will be given to a client when it requests DHCP. This binding is about the client’s identity at DHCP time (typically the hardware address or a client identifier), and the reservation itself serves to ensure the server hands out that IP to that client. A fixed-address, on the other hand, is a DNS object that statically maps a hostname to a particular IP, independent of DHCP. It doesn’t rely on DHCP to function; it’s about DNS resolution rather than a DHCP binding.

The statement identified as the best differentiator reflects that a reservation is defined in terms of the DHCP identity of the client and does not carry a separate client identifier within the object itself, whereas a fixed-address is purely a DNS-level entry without DHCP identity context. In other words, the reservation is the DHCP-side binding tied to a client identity, not a DNS client-identifier field, while a fixed-address operates outside DHCP and provides a static IP for a host name.

The other options don’t capture the core distinction: a fixed-address isn’t about DHCP options for configuration, and a reservation isn’t inherently global routability.