Active Directory, Second Edition

Active Directory Integrated DNS

If you’ve decided to host the AD DNS zones on your domain controllers, you should strongly consider using AD integrated zones. This section will explain some of the benefits of using AD integrated DNS versus standard primary zones.

In the normal world of DNS, you have two types of name servers: primary and secondary (a.k.a. slaves). The primary name server for a zone holds the data for the zone in a file on the host and reads the entries from there. Each zone typically has only one primary. A secondary gets the contents of its zone from the primary that is authoritative for the zone. Each primary name server can have multiple secondary name servers. When a secondary starts up, it contacts its primary and requests a copy of the relevant zone via zone transfer. The contents of the secondary file are then dynamically updated over time according to a set scheme. This is normally a periodic update or triggered automatically by a message from the primary stating that it has received an update. This is a very simplified picture, as each name server can host multiple zones, allowing each server to have a primary role for some zones and a secondary for others.

Each type of server can resolve name queries that come in. However, if a change must be made to the underlying contents of the DNS file, it has to be made on the primary name server for that zone. Secondary name servers cannot accept updates.^[5]

Another option available with Active Directory and Windows ...