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1.5 Must I Use DNS?
Despite the usefulness of the Domain Name System,
there are some situations in which it
doesn't pay to use it. There are other
name-resolution mechanisms besides DNS, some of which may be a
standard part of your operating system. Sometimes the overhead
involved in managing zones and their name servers outweighs the
benefits. On the other hand, there are circumstances in which you
have no other choice but to set up and manage name servers. Here are
some guidelines to help you make that decision.
1.5.1 If You're Connected to the Internet . . .
. . . DNS is a must. Think
of
DNS as the lingua franca of the Internet: nearly
all of the Internet's network services use DNS. That
includes the Web, electronic mail, remote terminal access, and file
transfer.On the other hand, this doesn't necessarily mean
that you
have
to set up and run zones by yourself
for yourself. If you've got
only a handful of hosts, you may be able to join an existing zone
(see Chapter 3) or find someone else to host your
zones for you. If you pay an Internet service provider for your
Internet connectivity, ask if they'll host your zone
for you, too. Even if you aren't already a customer,
there are companies who will help out, for a price.If you have a little more than a handful of hosts, or a lot more,
you'll probably want your own zone. And if you want
direct control over your zone and your name servers,
you'll want to manage it yourself. Read on!
1.5.2 If You Have Your Own TCP/IP-Based Internet . . .
. . . you probably want DNS. By an internet, we
don't mean just a single Ethernet of workstations
using TCP/IP (see the next
section if you thought that was what we meant); we mean a fairly
complex "network of networks."
Maybe you have several dozen Ethernet segments connected via routers,
for example.If your internet is basically homogeneous and your hosts
don't need DNS (say they don't run
TCP/IP at all), you may be able to do without it. But if
you've got a variety of hosts, especially if some of
those run some variety of Unix, you'll want DNS.
It'll simplify the distribution of host information
and rid you of any kludgy host-table distribution schemes you may
have cooked up.
1.5.3 If You Have Your Own Local Area Network or Site Network . . .
. . . and that network
isn't
connected to a larger
network, you can
probably get away without using DNS. You might consider using
Microsoft's
Windows
Internet Name Service (WINS), host tables, or Sun's
Network Information Service (NIS)
product.But if you need distributed administration or have trouble
maintaining the consistency of data on your network, DNS may be for
you. And if your network is likely to soon be connected to another
network, such as your corporate internet or the Internet, it would be
wise to start up your zones now.
