Which DNS server is contacted by clients, both local and over the Internet, to resolve DNS queries for the organization's domains?

Which DNS server is contacted by clients, both local and over the Internet, to resolve DNS queries for the organization's domains?

• A. Secondary DNS server
• B. Caching DNS server
• C. Primary DNS server
• D. Recursive DNS server

Answer: (C)

In DNS, the primary (master) server for a zone is the authoritative source for that domain’s records. When clients—whether inside the organization or remote—need to resolve names in the organization’s domain, they rely on the server that holds the definitive zone data. The primary DNS server stores the original zone file with all DNS records and answers queries directly as the authoritative source. The secondary DNS server is a backup copy that provides redundancy by holding a replicated zone, but it isn’t the primary source of truth. A caching server speeds repeated lookups by storing recent answers, but it doesn’t provide the initial authoritative data. A recursive DNS server initiates resolution by querying authoritative servers to obtain answers, but the ultimate source for the domain’s records is the primary DNS server.

In DNS, the primary (master) server for a zone is the authoritative source for that domain’s records. When clients—whether inside the organization or remote—need to resolve names in the organization’s domain, they rely on the server that holds the definitive zone data. The primary DNS server stores the original zone file with all DNS records and answers queries directly as the authoritative source. The secondary DNS server is a backup copy that provides redundancy by holding a replicated zone, but it isn’t the primary source of truth. A caching server speeds repeated lookups by storing recent answers, but it doesn’t provide the initial authoritative data. A recursive DNS server initiates resolution by querying authoritative servers to obtain answers, but the ultimate source for the domain’s records is the primary DNS server.