3.3.4 DNS Zones
A zone is a contiguous portion of the domain namespace for which a DNS server has authority to resolve
DNS queries. You can divide the DNS namespace into zones, which store name information about one or
more DNS domains or portions of a DNS domain. For each DNS domain name included in a zone, the zone
becomes the authoritative source for information about that domain. To limit the number of DNS servers on
your network, you can configure a single DNS server to support, or host, multiple zones. You can also
configure multiple servers to host one or more zones to provide fault tolerance and distribute the name
resolution and administrative workloads. Multiple zones in a domain name space are used to distribute
administrative tasks to different groups. However, a zone must encompass a contiguous domain name space.
For example, you cannot create a zone that consists of only the studyguides.testking.com and
qae.testking.com domains, because these two domains are not contiguous ľ the studyguides and the qae
subdomains are independent of each other and can only be combined into a single DNS zone if the
testking.com domain is also included in the zone.