Dynamic Update

Dynamic Update is a variation of the Domain Name System (DNS) defined in Request for Comments (RFC) 2136 and supported by Active Directory in Microsoft Windows Server.

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What is Dynamic Update?

A variation of the Domain Name System (DNS) defined in Request for Comments (RFC) 2136 and supported by Active Directory in Microsoft Windows 2000.

The dynamic update protocol provides support for dynamic updates of zone file information between domain controllers. Instead of using primary and secondary zones, Active Directory reuses zones.

What is Dynamic Update?

Dynamic update lies at the heart of Active Directory because domain names in Windows 2000 are also DNS names. For example, northwind.microsoft.com can be both a legal DNS name and the name of a Windows 2000 domain.

Ordinary DNS must be administered manually. Administrators must perform all changes to the DNS database or zone files manually. Zone files are propagated between DNS servers by zone transfers, which occur periodically.

Dynamic update lets computers running Windows 2000 with dynamically assigned IP addresses register both their host name and IP address information in the DNS database when they initialize on the network. Dynamic update can thus integrate the DNS and Dynamic Host Configuration Protocol (DHCP) services. Dynamic update also supports new types of server-to-server messages that allow individual resource records or sets of records to be added or deleted in a server’s zone.

When DNS is integrated with Active Directory for dynamic update, administrators must enable and manage the following zones:

  • The DNS root zone
  • DNS forward lookup zones
  • DNS reverse lookup zones

Dynamic update is similar to ordinary DNS in that zone update operations occur using primary or master servers only. Dynamic update, however, allows primary servers to receive updates initialed by a specified list of “authorized servers,” which can include secondary zone servers, domain controllers, and other servers that perform name registration services, such as Windows Internet Name Service (WINS) or DHCP servers.

NOTE

You can use the DNS Manager snap-in for the Microsoft Management Console (MMC) to enable Active Directory integration on an existing DNS server. The zone file information will be written into Active Directory.