What is the role of a DNS recursive resolver in name resolution?

• A. It resolves domain names by querying authoritative servers on behalf of the client
• B. It stores permanent DNS records for domains
• C. It routes packets at the transport layer
• D. It provides firewall filtering for DNS queries

Answer: (A)

A DNS recursive resolver answers a client’s domain-name query by doing the heavy lifting of contacting the appropriate DNS servers on the client’s behalf. It first checks its own cache for a recently resolved answer. If the answer isn’t cached, it starts at the root servers to locate the top-level domain’s authoritative server, then moves down the chain (TLD servers to authoritative servers for the domain) until it retrieves the definitive IP address. The resolver then returns that IP to the client and stores the result in its cache for future requests. It does not hold permanent zone data—that role belongs to the authoritative servers—nor does it route transport-layer packets or apply firewall filtering to DNS queries. This recursive behavior keeps the client interface simple and reduces the need for each client to know where to look up every domain.