What is a DNS zone?
A DNS zone is a specific part of the domain namespace that belongs to, is assigned to, and is managed by a certain administrator or organization. It’s the space on the nameserver that is assigned to a certain legal entity. For instance, organizations have their own DNS zones on a namespace that only belongs to them, allowing them to have more granular control of DNS components. A single DNS namespace can have one or more DNS zones, and a different DNS service or host manages each individual DNS zone.
Within one DNS zone, a domain and multiple subdomains can be managed by one entity So, a DNS zone is not one domain name or one DNS server because a DNS zone can contain multiple subdomains, and one server can host multiple DNS zones. A DNS zone is useful for administrative purposes, such as delegating tasks.
See also: DNS transfer zone, zone file, DNS record, DNS
How does a DNS zone work?
A DNS zone works by storing DNS records for a domain and its subdomains. When a user tries to access a resource within that domain, a DNS query is sent to resolve the domain name to an IP address.
The authoritative DNS server for the domain checks the DNS zone file and responds with the relevant DNS records. The recursive DNS server then returns the resolved IP address to the user's device, allowing it to connect to the requested resource.
DNS zones help maintain the structure and organization of the Domain Name System by managing DNS records for individual domains and their subdomains.
What are the types of DNS zones?
- Primary DNS zone. The primary DNS zone is also called the master DNS zone. The primary DNS zone contains the original zone file – all the zone’s DNS records.
- Secondary DNS zone. The secondary DNS zone is also called the slave DNS zone. It contains a copy of the zone file, and you can use it to boost performance, create backups of your DNS records, redundancy, and hide your primary DNS zone.
- Stub zone. A stub zone only contains the necessary DNS records to identify the authoritative DNS servers for a domain, such as NS records and glue records.
- Forward zone. A forward zone is used to forward DNS queries for a specific domain to another set of DNS servers, often used in situations where a separate DNS infrastructure is responsible for a particular domain.
