With a recursive DNS query, the DNS server will contact any other DNS servers it knows about to resolve the request.

• A. True
• B. False
• C. Not sure
• D. It depends

Answer: (B)

Recursion means the resolver takes on the burden of finding the final answer for the client. It will query other DNS servers as needed, but it doesn’t reach out to every server it knows about. If the answer is already cached, it can respond immediately without contacting anyone. If it isn’t cached, the resolver asks the root servers, then the appropriate TLD servers, then the domain’s authoritative servers, following referrals until it can provide a definitive answer or an error. So the resolver does not contact all known servers; it only queries the ones necessary to resolve the name. That’s why the statement is false.