DC ve ADC'lerde Preferred DNS adresleri

When a zone that this DNS server hosts is a primary zone, the
DNS server is the primary source for information about this zone, and
it stores the master copy of zone data in a local file or in AD DS. When
the zone is stored in a file, by default the primary zone file is named
zone_name.dns and it is located in the %windir%\System32\Dns
folder on the server.

When a zone that this DNS server hosts is a secondary zone,
this DNS server is a secondary source for information about this zone.
The zone at this server must be obtained from another remote DNS server
computer that also hosts the zone. This DNS server must have network
access to the remote DNS server that supplies this server with updated
information about the zone. Because a secondary zone is merely a copy of
a primary zone that is hosted on another server, it cannot be stored in
AD DS.

When a zone that this DNS server hosts is a stub zone, this
DNS server is a source only for information about the authoritative name
servers for this zone. The zone at this server must be obtained from
another DNS server that hosts the zone. This DNS server must have
network access to the remote DNS server to copy the authoritative name
server information about the zone.

You can use stub zones to:

• Keep delegated zone information current. By updating a stub zone for one
  of its child zones regularly, the DNS server that hosts both the parent
  zone and the stub zone will maintain a current list of authoritative
  DNS servers for the child zone.

• Improve name resolution. Stub zones enable a DNS server to perform
  recursion using the stub zone's list of name servers, without having to
  query the Internet or an internal root server for the DNS namespace.

• Simplify DNS administration. By using stub zones throughout your DNS
  infrastructure, you can distribute a list of the authoritative DNS
  servers for a zone without using secondary zones. However, stub zones do
  not serve the same purpose as secondary zones, and they are not an
  alternative for enhancing redundancy and load sharing.

There are two lists of DNS servers involved in the loading
and maintenance of a stub zone:

• The list of master servers from which the DNS server loads and updates a
  stub zone. A master server may be a primary or secondary DNS server for
  the zone. In both cases, it will have a complete list of the DNS
  servers for the zone.

• The list of the authoritative DNS servers for a zone. This list is
  contained in the stub zone using name server (NS) resource records.

When a DNS server loads a stub zone, such as
widgets.tailspintoys.com, it queries the master servers, which can be in
different locations, for the necessary resource records of the
authoritative servers for the zone widgets.tailspintoys.com. The list of
master servers may contain a single server or multiple servers, and it
can be changed anytime.