• In Step 1, the client asks the server for the IP address for www.realtimepublishers.com.
• The DNS server first looks in its local cache to see if a record exists. This record may exist because the DNS server had previously attempted a resolution. If the record exists in the DNS cache, the server responds immediately with the answer. In our case, the server does not have a copy of the response locally, so the process continues.
• The DNS server then looks in its cache again, but this time after appending its DNS suffix to the query. In this case, the query will resemble www.realtimepublishers.com.abccorp.com. Why does this step occur? In the Windows world, administrators often make resolution requests to DNS servers using just a server's host name alone. This is similar to the situation when you enter nslookup exchangeserver rather than fully qualifying the name nslookup exchangeserver.abccorp.com. In order to make this process possible, Windows DNS is configured to append its primary suffix in any attempt at resolution. This response obviously will not be present in the local database or cache, so the process continues further.
• For Step 2, once the server realizes that no combination of the client's request along with any permutations of its DNS suffix are locally available, the server next contacts the Internet root servers - . (dot) - in the diagram. The DNS server asks the root server for the response to the entire query www.realtimepublishers.com. This query fails as the Internet root servers are responsible for storing information not about our entire query, but only for the answer to the rightmost element in our request - the .com portion. (dot) does not respond with an answer, but instead a pointer to the DNS server that it believes to be authoritative for .com.
• Our server then moves to Step 3. Armed with information about the location of .com, our local DNS server then queries this server with its entire query. The server authoritative for .com also does not have a full and complete answer for the query. It does, however, have information about the server that is authoritative for realtimepublishers.com. This information is returned back to dnsserver.abccorp.com.
• Now two-thirds of the way to completing the request, our server makes one final attempt. It knows the server that is authoritative for the realtimepublishers.com domain, but it needs to know the specific IP address for the server named "www". Getting ever closer to a response, our local DNS server moves to Step 4 and presents its entire query to the authoritative server for realtimepublishers.com. Unlike all the other servers, this server contains the full and complete answer and responds with the IP address for www.realtimepublishers.com.
• With the IP address in hand, in Step 5 the local DNS server then returns the information back to the client. The client can then use this information locally for any of its local uses.

Our series concludes with Part 4 tomorrow.