Configure Network Services - MCSA Windows Server 2012 R2: Installation and Configuration Study Guide - page 63

Any DNS server implementation supporting Service Location Resource Records (see RFC
2782) and Dynamic Updates (RFC 2136) is sufficient to provide the name service for any
operating system running Windows 2003 software and newer.
DNS Client A DNS client is any machine that issues queries to a DNS server. The client
hostname may or may not be registered in a DNS database. Clients issue DNS requests
through processes called resolvers . You'll sometimes see the terms client and resolver used
synonymously.
Resolver Resolvers are software processes, sometimes implemented in software libraries
that handle the actual process of finding the answers to queries for DNS data. The resolver
is also built into many larger pieces of software so that external libraries don't have to
be called to make and process DNS queries. Resolvers can be what you'd consider client
computers or other DNS servers attempting to resolve an answer on behalf of a client (for
example, Internet Explorer).
Query A query is a request for information sent to a DNS server. Three types of queries
can be made to a DNS server: recursive, inverse, and iterative. I'll discuss the differences
between these query types in the section “DNS Queries,” a bit later in the chapter.
Understanding the DNS Process
To help you understand the DNS process, I will start by covering the differences between
Dynamic DNS and Non-Dynamic DNS. During this discussion, you will learn how
Dynamic DNS populates the DNS database. You'll also see how to implement security
for Dynamic DNS. I will then talk about the workings of different types of DNS queries.
Finally, I will discuss caching and time to live (TTL). You'll learn how to determine the best
setting for your organization.
Dynamic DNS and Non-Dynamic DNS
To understand Dynamic DNS and Non-Dynamic DNS, you must go back in time. (Here is
where the TV screen always used to get wavy.) Many years ago when many of us worked
on Windows NT 3.51 and Windows NT 4.0, almost all Microsoft networks used Windows
Internet Name Service (WINS) to do their TCP/IP name resolution. Windows versions
95/98 and NT 4.0 Professional were all built on the idea of using WINS. This worked
out well for administrators because WINS was dynamic (which meant that once it was
installed, it automatically built its own database). Back then, there was no such thing as
Dynamic DNS; administrators had to enter DNS records into the server manually. This is
important to know even today. If you have clients still running any of these older operating
systems (95/98 or NT 4), these clients cannot use Dynamic DNS.
Now let's move forward in time to the release of Windows Server 2000. Microsoft
announced that DNS was going to be the name resolution method of choice. Many
administrators (myself included) did not look forward to the switch. Because there was no
such thing as Dynamic DNS, most administrators had nightmares about manually entering