DNS can perform two types of queries. What are they?

DNS can perform two types of queries. What are they?

• A. Iterative and Recursive.
• B. Synchronous and Asynchronous.
• C. Local and Remote.
• D. Bulk and Single.

Answer: (A)

In DNS, two query modes describe how a resolution is performed: recursive and iterative. In a recursive query, the client asks a DNS server to fully resolve a name; the server takes on the task, contacting other DNS servers as needed, following referrals, and finally returning the actual IP address (or an error) to the client. In an iterative query, the client asks a server for the best answer it can provide, and the server responds with either a final answer or a referral to another server that can continue the search; the client then queries that next server and repeats until it gets the answer. This distinction matters because it determines who does the work and how many steps the client must perform. Typically, end-user devices send recursive queries to a local resolver, which then performs iterative queries to root and authoritative servers to obtain the final result.

In DNS, two query modes describe how a resolution is performed: recursive and iterative. In a recursive query, the client asks a DNS server to fully resolve a name; the server takes on the task, contacting other DNS servers as needed, following referrals, and finally returning the actual IP address (or an error) to the client. In an iterative query, the client asks a server for the best answer it can provide, and the server responds with either a final answer or a referral to another server that can continue the search; the client then queries that next server and repeats until it gets the answer. This distinction matters because it determines who does the work and how many steps the client must perform. Typically, end-user devices send recursive queries to a local resolver, which then performs iterative queries to root and authoritative servers to obtain the final result.