OBTAIN AN IP ADDRESS BY USING DHCPBEFORE YOU BEGIN THIS EXERCISE, YOU...

13-31Lesson 2 Understanding the Domain Name System

Multiple name servers act as a backup to the name server containing the primary zone

database file. Multiple name servers provide the following advantages:

■

They perform zone transfers. The additional name servers obtain a copy of the

zone database file from the name server that contains the primary database zone

file. This process is called a zone transfer. These name servers periodically query

the name server containing the primary zone database file for updated zone data.

■

They provide redundancy. If the name server containing the primary zone data-

base file fails, the additional name servers can provide service.

■

They improve access speed for remote locations. If there are a number of clients

in remote locations, use additional name servers to reduce query traffic across

slow wide area network (WAN) links.

■

They reduce the load on the name server containing the primary zone database

file.

Real World Active Directory and DNS

Active Directory and DNS are tightly integrated—they even share a common

namespace. It is essential, therefore, that you understand how each system works

and how they work together.

DNS is the locator service used by Active Directory (and by many other Windows

components). Active Directory makes its services available to the network by

publishing them in DNS. When a domain controller is installed (or when services

are added to it), the domain controller uses dynamic updates to register its ser-

vices as SRV records in DNS. Clients can then locate services through simple DNS

queries. The Microsoft DNS Service runs on every Windows Server 2003 domain

controller by default.

Lesson Review

The following questions are intended to reinforce key information presented in this

lesson. If you are unable to answer a question, review the lesson materials and try the

question again. You can find answers to the questions in the “Questions and Answers”

section at the end of this chapter.