Delegating a Zone

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Domain Name System (DNS) provides the option of dividing up the namespace into one or more zones, which can then be stored, distributed, and replicated to other DNS servers. When deciding whether to divide your DNS namespace to make additional zones, consider the following reasons to use additional zones:

  • You want to delegate management of part of your DNS namespace to another location or department in your organization.

  • You want to divide one large zone into smaller zones for distributing traffic loads among multiple servers, improving DNS name resolution performance, or creating a more fault-tolerant DNS environment.

  • You want to extend the namespace by adding numerous subdomains at once, for example, to accommodate the opening of a new branch or site.

If, for any of these reasons, your network can benefit from delegating zones, it may make sense to restructure your namespace by adding additional zones. When choosing how to structure zones, use a plan that reflects the structure of your organization.

When you delegate zones within your namespace, be aware that for each new zone you create, you will need delegation records in other zones that point to the authoritative DNS servers for the new zone. This is necessary both to transfer authority and to provide correct referral to other DNS servers and clients of the new servers that are being made authoritative for the new zone.

When a standard primary zone is first created, it is stored as a text file that contains all resource record information on a single DNS server. This server acts as the primary master for the zone. Zone information can be replicated to other DNS servers to improve fault tolerance and server performance.

When you structure your zones, there are several good reasons to use additional DNS servers for zone replication:

  • Added DNS servers provide zone redundancy, enabling DNS names in the zone to be resolved for clients if a primary server for the zone stops responding.

  • Added DNS servers can be placed so as to reduce DNS network traffic. For example, adding a DNS server to the opposing side of a low-speed, wide area network (WAN) link can be useful in managing and reducing network traffic.

  • Additional secondary servers can be used to reduce loads on a primary server for a zone.

For more information about planning DNS zones, see Deploying Domain Name System (DNS) on the Microsoft Web site (

Task requirements

To begin this task, perform the following requirements:

  • Install Dnscmd.

  • Install Nslookup.

To complete this task, perform one of the following procedures:

See Also

Other Resources

Deploying Domain Name System (DNS)