IgNiTeD SoUL

If a DNS Server does not have an entry in its database for the remote host specified in a client request, it can respond to the client with the address of a DNS Server more likely to have that information, or it can query the other DNS server itself. This process can take place recursively until either the client computer receives the IP address or the DNS server establishes that the queried name cannot be resolved. DNS Servers to which other DNS Servers forward requests are known as Forwarders.

The Windows 2008 DNS Server service extends the standard forwarder configuration by using conditional forwarders. A Conditional Forwarder is a DNS Server that forwards DNS Query according to the DNS domain name in the query. For example, you can configure a DNS server to forward all the queries that it receives for names ending with Ignitedsoul.com to the IP address of one or more specified DNS Servers. This feature is particularly useful on extranets, where several organizations and domains access the same private internetwork.

Other Posts Related to DNS:

https://ignitedsoul.com/2012/01/25/dns-record-keeping/