Which statement about DNS resolvers is accurate?

Which statement about DNS resolvers is accurate?

• A. They store zone data in text files.
• B. They are clients that request domain information from a DNS, separate from resolvers.
• C. Any host or client needing to look up domain information is a resolver.
• D. They convert IP addresses to domain names.

Answer: (C)

DNS resolvers are the client-side component on a host that performs lookups to translate domain names into IP addresses. When a host needs to reach a domain, it uses its resolver to query DNS and obtain the corresponding address, so the host effectively acts as a resolver for its own lookups. This makes the statement that any host or client needing to look up domain information is a resolver the best fit, because the resolver is the querying entity on the client side. The other ideas aren’t accurate: storing zone data belongs to DNS servers, not resolvers; the notion of separate clients from resolvers mixes up the roles since the resolver is the client that asks for information; and converting IPs back to domain names is a reverse lookup and not the primary function of a resolver, which is to resolve domain names to addresses.

DNS resolvers are the client-side component on a host that performs lookups to translate domain names into IP addresses. When a host needs to reach a domain, it uses its resolver to query DNS and obtain the corresponding address, so the host effectively acts as a resolver for its own lookups. This makes the statement that any host or client needing to look up domain information is a resolver the best fit, because the resolver is the querying entity on the client side. The other ideas aren’t accurate: storing zone data belongs to DNS servers, not resolvers; the notion of separate clients from resolvers mixes up the roles since the resolver is the client that asks for information; and converting IPs back to domain names is a reverse lookup and not the primary function of a resolver, which is to resolve domain names to addresses.