What is a Non-Authoritative DNS Server?

• A. A server that caches information from authoritative servers.
• B. A server that holds the original data for a domain.
• C. A server that translates domain names to IP addresses for end users.
• D. A server that verifies DNSSEC signatures.

Answer: (A)

Non-authoritative DNS servers are caching resolvers. Their main role is to store responses that they’ve learned from authoritative servers so they can answer future queries quickly without asking the authoritative source every time. They don’t hold the original zone data themselves; that data lives on the authoritative servers for each domain. If a requested record isn’t in the cache or the cached entry is stale, the non-authoritative server forwards the query to an authoritative server to refresh it.

That distinction matters because holding the original data is what an authoritative server does, not the non-authoritative one. Translating domain names to IP addresses is the basic function of DNS, and a non-authoritative server can perform that translation using cached results, but its defining feature is caching rather than storing the original data. Verifying DNSSEC signatures is a specialized capability of DNSSEC-enabled resolvers, which is not inherent to all non-authoritative caching servers.