The domain name system (DNS) is separated into several zones. Each zone is meant to differentiate between the managed sections in the DNS naming hierarchy. A zone is a part of the DNS naming that can be managed by an organization, administrator, person or anyone who is responsible for maintaining said zone.
A DNS zone can be used in an administrative case that allows for a more granular view of controlling DNS components, like authoritative nameservers.
DNS Zone File – What is it?
A DNS zone file is a plain text file that is located in a DNS server that includes an accurate representation of each zone and contains every record for each domain within a zone. Records are used to direct how a DNS zone propagates to secondary name servers. An SOA record is created by default for each domain added into the DNS Made Easy system. SOA records include important information like contact information of the zone admin.
DNS Zone Types
Primary Zone
Referred to as the main zone that contains the read/write copy of the data
Secondary Zone
Holds a read-only copy of the primary zone information. It cannot perform updates and can only receive them from the primary zone. It can, however, perform as an authoritative zone to alleviate some workload from the primary.
Stub Zone
Operates similarly to a secondary zone but only stores partial data to reduce zone transfers. Instead, it passes the requests to authoritative servers.
Forward Lookup Zone
Provides the IP address resolution with the hostname’s IP information
Reverse Lookup Zone
Resolves IP addresses into hostnames
DNS Zone File Directives
$TTL
defines the time to live value for the zone
$ORIGIN
defines the base name for unqualified records. These are any names that are used in resource records that do not end with a trailing period (e.g.: domain.com.) and are appended to the base name using this directive.
$INCLUDE
allows inclusions of other zone files within an existing zone file to allow for additional settings to be stored that are not part of the file. This can be used to keep each subdomain’s records in separate files.
DNS Zone Example
What is a DNS Server
A nameserver is a component of DNS that translates domain names into machine-readable IP addresses. These servers are also what allow devices and resources to connect with one another on the web. There are several different server types that operate within the domain name system: recursive, root, TLD, and authoritative.
DNS Zone Tip
Did you know that a DNS zone can contain several subdomains and multiple zones can exist on the same nameserver. While DNS zones are not necessarily separated physically from each other, DNS zones are specifically used for delegating control.