DNS queries actually occur in one of two flavors. The first, recursive queries occur when the DNS server being asked for resolution has the answer to the question the client is asking already within its database or local cache. For recursive queries, the DNS server will respond to the requesting client with either the answer or an error message. In this case the answer will always be the correct answer with a full response.

The other type of query is called an iterative query. In this case, the queried DNS server provides as much information that it has about the request. This information may come in the form of an IP address for another server that might have the answer to the query. It is this process where many Windows administrators get confused about the overall process. To better explain this process, let's take a look at it in detail using Figure 1 above as a guide.

In Figure 1 above, the desktop is currently configured with an FQDN of client42.abccorp.com. The desktop points to the server dnsserver.abccorp.com as its primary DNS server. The DNS suffix for both machines is abccorp.com. This suffix is important because it is used by the DNS server to help in identifying the record desired by the client. In this example, the client is attempting to resolve www.realtimepublishers.com. Perhaps the user on this desktop is interested in learning more about the great e-books and other guides that can be found on this web site. When the client begins the resolution process, the following conversations happen:

Stay tuned tomorrow for the continuing saga and Part 3!