namenservers

Nameservers are a core component of the Domain Name System (DNS). They are servers that hold DNS records for one or more domain names and respond to queries that translate human-readable domain names into machine-readable addresses or other DNS data. In this sense, name servers act as the authoritative source for the zone data they manage.

There are two main types of name servers: authoritative and recursive. Authoritative name servers store the actual zone files for domains and provide definitive answers about those domains. Recursive resolvers, typically operated by ISPs or organizations, query other name servers on behalf of clients and cache the answers to speed up subsequent requests.

A domain is delegated to one or more authoritative name servers through NS records in its zone. The registry for the top-level domain (and the registrar at the domain level) maintains information about which name servers are responsible for a domain. A domain’s zone file contains various records, such as A or AAAA (address records), MX (mail servers), CNAME (aliases), NS (delegation to other name servers), and SOA (start of authority). Glue records may be required when a name server’s hostname is within the same domain that it serves.

During resolution, a client’s recursive resolver queries root servers, then TLD servers, and finally the domain’s authoritative servers to obtain the needed data. Results are cached to improve speed and reduce load.

Security and privacy measures, like DNSSEC (which signs DNS data) and DNS over TLS or DNS over HTTPS (for encrypted queries), aim to protect integrity and privacy, though deployment varies.

Proper configuration and consistent NS records across parent and child zones are essential to ensure reliable domain resolution and prevent outages.