Setting Up Your Own DNS (Kessler): " directory where the DNS program files reside. The remaining records each contain three fields which describe a DNS database file: the type of DNS information, the domain defined in the file, and the filename. There are six records that refer to DNS databases for which this DNS server has primary responsibility. The six domains defined here are:
foo.com: The DNS entries for the foo.com zone, which are in the file foo.com.zone.
210.168.192.in-addr.arpa: The foo.com domain is associated with the IP Class C address 192.168.210.0 (a valid IP address for use in a private network per RFC 1918). Reverse lookups (i.e., obtaining the host name from an IP address) are accomplished with a reverse database file. The name of the domain is the reverse dotted decimal notation of the domain's IP address, followed by in-addr.arpa, an indication of the use of IP addresses within the ARPA address assignment domain. "
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Editor's Note: TMI.... Please!!!