CACHE-ONLY DNS SERVER

All Internet hosts, including your computer when it is connected to the Internet, use a DNS server. Every time you go to a website, you need to look up the site's IP address using the name of the website. Your request for lookup is eventually passed to a DNS server somewhere.

But your request is one of thousands, even millions of requests being made at any one time across the Internet. The DNS lookup process requires that if your local DNS server is not authoritative for the domain that contains the host you are trying to reach, it should ask other servers to get an answer. Your local server could get quite busy performing these lookup requests, and this could slow down it's performance if it IS authoritative for a domain.

A DNS server can be configured to respond with answers from recursive lookup or stored in its cache only. This is done by not configuring any domains on the server. Cache-only servers are configured for recursive lookup as well. This creates a server that will respond to lookup requests by delivering answers from it's cache, or looking them up on other servers. This cache-only server will not be authoritative for any domains since it does not contain a complete copy of any domain's zone file. It is the job of a cache-only server to handle general lookups of Internet domains, and is completely blank when it is first turned on or rebooted. A cache-only server reduces the load placed on an Authoritative DNS server by handling the requests that don't pertain to the local domain.