What are the two types of authoritative zones?

• A. Forward Mapping, Reverse Mapping
• B. Primary and Secondary
• C. External Primary and External Secondary
• D. Recursive and Non-Recursive

Answer: (A)

The key idea is that DNS zones come in two directions of data they serve: forward lookups and reverse lookups. A forward lookup zone is where you map hostnames to IP addresses, using records like A and AAAA. A reverse lookup zone is where you map IP addresses back to hostnames, using PTR records. Both types are authoritative, meaning the DNS server hosting the zone is the source of truth for that data in its part of the namespace.

This makes forward mapping and reverse mapping the best answer because they describe the two directions DNS can resolve names, which is exactly how authoritative zones are categorized in practice. The other options describe different concepts—primary/secondary refer to who holds or replicates the zone data, while recursive/non-recursive describe resolver behavior—not the directional types of authoritative zones.