DNS is a hierarchical system, and zone delegation
connects the DNS layers together. A zone
delegation points to the next hierarchical level
down and then identifies the name servers that
are responsible for lower-level domain.
When deciding whether to divide a DNS
namespace to make additional zones, consider the
following scenarios in which you might use
additional zones:
• You need to delegate management of a part
of the DNS namespace to another
organizational location or department.
• You need to divide one large zone into smaller zones so you can distribute traffic loads among
multiple servers. This improves DNS name-resolution performance, and it creates a more fault-
tolerant DNS environment.
• You need to extend the namespace by adding numerous subdomains immediately to accommodate
the opening of a new branch or site.
Zone delegation works much the same way that a TLD works with a secondary level domain. The .com
DNS servers refer all requests for Microsoft.com zone name resolution to the DNS servers at Microsoft. In
this way, you delegate the Microsoft DNS zone from the .com zone. In a scenario where Microsoft has a
very vigorous Sales department with numerous computers and other devices with IP addresses, it would
make sense to create a zone named Sales.Microsoft.com to handle the extensive DNS workload for the
Sales department.
To create a delegation, the administrator right-clicks the Microsoft.com forward lookup zone and selects
the New Delegation item, which starts the New Delegation Wizard. The wizard walks the administrator
through the steps to delegate authority for a subdomain to a different zone, either on the current DNS
server or on another D