What is WINS?

Not satisfied with DNS, Microsoft invented another naming service for Windows, called WINS (Windows Internet Name Service). WINS is a Windows-specific name service for TCP/IP and is meant for networking geographically distant Windows computers (it typically isn’t used on a local area network). WINS not only maps names of servers but also maps names of workgroups and NT domains.
It’s unlikely that WINS will be around in the next generation of Windows machines (although it’s still around in Windows 98); Microsoft is taking a page from the competition’s automatic name services and directory services and will be rolling TCP/IP name services together with their username and password services. This will be called Active Directory.
The notion of a directory is similar to the name services concept, but it goes one step further: Instead of simply resolving a name to a number, directory services offer many pieces of vital data on the network. In particular, directory services allow users from all over to log in to the network rather than into a specific server; each server on the network relies on the directory services to assign security rights, and so on.

This is terrific because administrators no longer need to update multiple servers with username and password information; instead, they can administer updates from one point and distribute them throughout the network. Although the long-term goal has been simplification, which makes troubleshooting easier, beware of early implementations. Even Novell’s NDS—arguably the “best” directory service around (it’s been around a number of years and has a lot of support)—had a lot of problems out of the gate.
Some sort of directory service—whether it’s Microsoft’s, Novell’s, or Acme’s—is definitely in your future.

What is DNS?

Prologue for this article.
You’ve probably asked yourself in one of the preceding paragraphs, “How does www.co.chatham.ga.us get translated into 167.195.160.9?” Furthermore, why use names at all? People can deal with phone numbers, why not just use the IP number? These are good questions. The answer to the latter is that just because people can deal with a number doesn’t mean that they prefer to use a number. Which would you rather remember, 1-800-NETWORK or 1-800-638-9675? Obviously, most people prefer to remember a name. Actually, names are the better thing to use when networking, because numerical addresses can change during a reconfiguration or a move, whereas symbolic names typically stay the same.
Name-to-address translation (also known as name lookup or name resolution) occurs via name services. Very similar to the speed dial button on your phone, name services are the networking equivalent of an electronic phone book. They’re actually a lot cooler than your speed dial: For example, suppose you could say “Mom” to make your phone dial your mother.

DNS (Domain Name System)

Name services run as a service on any given name server; that is, a specific program runs on a name server that hands out an address when you give it a name. Like your speed dial buttons, you must program in a name entry; entering the correct number for a given name is important. In particular, TCP/IP name services, although powerful and able to handle millions and millions of names, isn’t exactly plug-and-play. The DNS (Domain Name Service) that you use when surfing the Web works pretty automatically for you once it’s configured correctly, and it will translate www.co.chatham.ga.us to 167.195.160.9. However, you’ll need to know the exact number of your DNS server. Unlike telephone information, DNS servers all have different addresses; verifying that a workstation’s DNS server is correct can be an important troubleshooting step

Note that most smaller sites that use TCP/IP usually don’t have DNS set up. Instead, each workstation has a local (hard drive) “hosts” file that lists the addresses and host names the workstation needs to get to. (Think of this as your personal phone book rather than the corporate directory.) As you can imagine, this gets hard to manage when you have more than a handful of workstations, unless the addresses of the servers never change. As sites grow, or as they get connected to the Internet, DNS servers are added. Can you imagine how big a single file with all the servers on the Internet would be? Fortunately, each DNS server for a given DNS zone is only responsible for its own information.
A DNS zone (its scope of responsibility for naming) can be huge—for example, .com has millions of subzones (yahoo.com, jotto.com, and so on); on the other hand, it can be small—for example, feldman.org lists only one host (www.feldman.org) and no subzones.
With DNS servers getting easier to manage and being a mandatory component of Internet access, you can expect to see more of them in smaller shops as time goes on. It’s worth mentioning that each DNS server is responsible for only its own zone, so if you can’t get to one particular address (say, yahoo.com) but can get to another (say, jotto.com), it may be that the name server responsible for that zone is down. On the Internet at large, this rarely happens, because the DNS organizers require back-up DNS servers for a zone. DNS problems are more likely to happen within a smaller organization’s intranet, particularly when all the eggs for that organization are in one basket.