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Lesson 3
Implementing a DNS Name Resolution Strategy
4-33
Creating Zones
A zone is an administrative entity you create on a DNS server to represent a
discrete
portion of the namespace. Administrators typically divide the DNS namespace
into
zones to store them on different servers and to delegate their
administration to different
people. Zones always consist of entire domains or subdomains. You can create
a zone
that contains multiple domains, as long as those domains are contiguous in
the DNS
namespace. For example, you can create a zone containing a parent domain and
its
child, because they are directly connected, but you cannot create a zone
containing
two child domains without their common parent, because the two children are
not
directly connected (see Figure 4-7).
adatum.com
hr.adatum.com
sales.adatum.com
Valid zone
adatum.com
hr.adatum.com
sales.adatum.com
Invalid zone
F04pm07
Figure 4-7
Valid zones must consist of contiguous domains
You can divide the DNS namespace into multiple zones and host them on a
single DNS
server if you want to, although there is usually no persuasive reason to do
so. The DNS
server in Windows Server 2003 can support as many as 200,000 zones on a
single
server, although it is hard to imagine what scenario would require this
many. In most
cases, an administrator creates multiple zones on a server and then
delegates most of
them to other servers, which then become responsible for hosting them.
Understanding Zone Types
Every zone consists of a zone database, which contains the resource records
for the
domains in that zone. The DNS server in Windows Server 2003 supports three
zone
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