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 standard with 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. Following are some guidelines to help you make
that decision.

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 World Wide 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!

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 a forest of  AppleTalk nets and a handful of Apollo token rings.

If your internet is basically homogeneous and your hosts don't need DNS (say you
have a big DECnet or OSI internet), 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.

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'd
be wise to start up your zones now.