Which is not a type of DNS query?

Which is not a type of DNS query?

• A. Recursive
• B. Iterative
• C. Non-iterative
• D. Inverse

Answer: (C)

DNS queries are handled in two main modes: recursive and iterative. A recursive query asks the resolver to obtain the final answer, performing all the lookups and returning the complete result or an error. An iterative query is when a server returns the best answer it can and directs the client to another server for further information, until an authoritative source is reached. The term non-iterative isn’t a formal DNS query type you’ll encounter in the protocol; there is no recognized non-iterative mode. Inverse, on the other hand, refers to reverse lookups (mapping an IP back to a domain) and is a real concept, though not as commonly used today. Therefore, the option that does not fit as a type of DNS query is non-iterative.

DNS queries are handled in two main modes: recursive and iterative. A recursive query asks the resolver to obtain the final answer, performing all the lookups and returning the complete result or an error. An iterative query is when a server returns the best answer it can and directs the client to another server for further information, until an authoritative source is reached. The term non-iterative isn’t a formal DNS query type you’ll encounter in the protocol; there is no recognized non-iterative mode. Inverse, on the other hand, refers to reverse lookups (mapping an IP back to a domain) and is a real concept, though not as commonly used today. Therefore, the option that does not fit as a type of DNS query is non-iterative.