Objective 2.7

Plan a Host Name Resolution Strategy

15-41

Objective 2.7

Plan a Host Name Resolution

Strategy

Name resolution is the process of converting a computer’s name into an IP address.

All TCP/IP systems communicate using IP addresses; the names are just a conve-

nience for the user. Networks running Windows Server 2003 can use several different

name resolution mechanisms, but the primary one is the Domain Name System

(DNS). Windows Server 2003 includes a DNS Server service that is compatible with

virtually all the other DNS implementations used on the Internet. Your computers

need access to a DNS server if they are connected to the Internet or if you use the

Active Directory directory service. Active Directory networks nearly always have their

own DNS servers, but for Internet access, you can use your own DNS servers or

those supplied by your ISP.

To resolve Internet names, no special effort is needed beyond installing a DNS server

and configuring your computers to use it. The server interacts with other DNS servers

on the Internet to resolve the name of any Internet computer. To resolve your own

computers’ names, you must create your own DNS namespace. The DNS namespace

is a hierarchy of domains, with each domain containing a number of hosts. To cre-

ate your own public DNS namespace, you must register a second-level domain name

in one of the existing Internet top-level domains (such as .com or .net). Then, you

can create as many subdomains as you need beneath that second-level domain. The

primary reason for creating subdomains is to delegate administrative responsibility

for certain parts of the namespace. For example, if your organization has several

offices and you want each one to manage its own DNS names, you can create a sub-

domain for each office.

In many cases, organizations have both internal (that is, private) and external (Internet)

networks, which they must keep separated. To design a DNS namespace for this type

of situation, you have three alternatives:

■

Use the same domain name By using the same domain name for your internal

and external networks, you stand the risk of having computers with the same

name on both networks. Microsoft strongly recommends against this option.

■

Use two domain names Having two different domain names for your internal

and external networks eliminates the possibility of name conflicts, but you must

pay a registration fee for the external, publicly available, domain name and it can