Adding a Caching-Only DNS Server

Applies To: Windows Server 2008

Although all Domain Name System (DNS) servers cache queries that they have resolved, caching-only servers have only one function: they perform queries, cache the answers, and return the results. Caching-only DNS servers are not authoritative for any domains, and the information that they contain is limited to what they cache while they resolve queries.

A caching-only DNS server can be useful at a site where DNS functionality is needed locally but it is not desirable—from the administrative perspective—to create a separate domain or zone for that location, such as a branch office. Query-resolution information is obtained over time from other servers as client requests are serviced. Consequently, the peak network traffic between the caching-only server and other DNS servers occurs when the caching-only server is first put into service. However, if you are dealing with a slow-speed, wide area network (WAN) link between sites, this option might be ideal. This is because, after the cache is built, WAN traffic decreases because the caching-only server does not perform zone transfers, which can use a lot of network resources in WAN environments.

To complete this task, perform the following procedures