Microsoft Knowledge Base Article 255913 contains the following summary:

One feature of Windows 2000 Domain Name System (DNS) is its support for dynamic host updates (documented in RFC 2136) . To take advantage of this feature, Windows 2000 DNS can be deployed in environments that have no other DNS servers, as well as in environments that already have non-dynamic DNS servers implemented (Microsoft Windows NT 4.0 DNS server and BIND 4.9.7 and earlier, etc.) . When you are deploying Windows 2000 DNS in an environment that already has BIND or Windows NT 4.0 DNS servers implemented, you have several integration options:

  • Upgrade Windows NT 4.0 DNS servers to Windows 2000.
  • Migrate zones from non-dynamic authoritative DNS servers to servers running Windows 2000 DNS.
  • Delegate child DNS domains under a parent DNS domain. For Active Directory domain names that do not have the same name as the root of a zone, delegate the subdomain to Windows 2000 DNS. For example, if the name of the Active Directory domain is dev.reskit.com and the zone that contains this name is reskit.com, delegate dev.reskit.com to a Windows 2000-based server running DNS.
  • Delegate each of the subdomains used by the domain controller (DC) locator records (SRV records) to a Windows 2000-based server . These subdomains are _msdcs.reskit.com, _sites.reskit.com, _tcp.reskit.com, and _udp.reskit.com . This option would be used where Active Directory domain names (for example, reskit.com) that are the same as the name of the root of a zone (for example, reskit.com), cannot be delegated directly to a Windows 2000-based server running DNS . Optionally, clients may be members of the Active Directory domain called reskit.com, but can register in the DNS zone called dynamic.reskit.com.
This article documents the fourth option listed above, how to integrate Windows 2000 DNS into an organization that already has a DNS namespace implemented in which the DNS server that is authoritative for the zone with the name of the Active Directory domain does not support RFC 2136 (dynamic updates) . This article also discusses a scenario in which domain members use a primary DNS suffix different from the name of the Active Directory domain to allow dynamic registration of DNS records by Windows 2000-based computers when the DNS server authoritative for the zone with the name of the Active Directory domain does not support dynamic DNS updates.