DNS on Windows Server 2003, 3rd Edition

The Whole Enchilada

What this amounts to is a resolution process that, taken as a whole, looks like Figure 2-13.

Figure 2-13. The resolution process

A resolver queries a local name server, which then sends iterative queries to a number of other name servers in pursuit of an answer for the resolver. Each name server it queries refers it to another name server that is authoritative for a zone further down in the namespace and closer to the domain name sought. Finally, the local name server queries the authoritative name server, which returns an answer. All the while, the local name server uses each response it receives—whether a referral or the answer—to update the RTT of the responding name server, which will help it decide which name servers to query to resolve domain names in the future.