DNS zone

A DNS zone is a distinct, contiguous portion of the domain name space for which administrative responsibility has been delegated to a single manager. A zone contains DNS records, which map domain names to IP addresses and other resources. It represents a delegation point within the DNS hierarchy.

Zones are typically defined for a domain and any subdomains for which the parent domain relinquishes administrative control. A zone is served by one or more authoritative name servers, which are responsible for providing DNS information for that zone.

A crucial element of a DNS zone is the Start of Authority (SOA) record. The SOA record specifies critical information about the zone, including the primary name server, the email address of the zone administrator, and various timers that control how other DNS servers cache and refresh zone data. Changes made to a DNS zone are propagated from the primary name server to secondary name servers through a process called zone transfer.

The boundaries of a DNS zone are determined by delegation records in the parent zone. These delegation records, often NS (Name Server) records, point to the authoritative name servers for the delegated zone. The creation and management of DNS zones are fundamental to ensuring the correct resolution of domain names across the internet.