DNS Configuration and Management Manual (G06.27+, H06.05+, J06.03+)

HP DNS Configuration and Management Manual—529432-003
A-1
A DNS and BIND Basics
The Berkeley Internet Name Domain (BIND) is a Berkeley implementation of the
Domain Name System (DNS). BIND is a distributed-network, information-lookup
service that maps host names to Internet addresses and maps Internet addresses to
host names. BIND also facilitates Internet mail routing by supplying a list of hosts that
accept mail for other hosts. This appendix describes the BIND features and
components and how they work. It contains:
•
Components of DNS on page A-1
•
How BIND Works on page A-4
•
The BIND Configuration File on page A-18
Components of DNS
DNS consists of:
•
DNS Name Space on page A-1
•
The Resolver on page A-3
•
The Name Server on page A-3
•
Lightweight Resolver Library and Demon on page A-4
DNS Name Space
The DNS name space is a hierarchical organization of all the hosts on the Internet. It is
a tree structure, similar to the structure of UNIX directories. The root of the hierarchy is
represented by a dot (.). Under the root, the top-level Internet domains
com
(commercial businesses),
edu (educational institutions), gov (government agencies),
mil (military and defense), net (network-related organizations), and org (other
organizations) are included. Under each top-level domain are subdomains. For
example, the
edu domain has subdomains like purdue, ukans, and berkeley. In
turn, each subdomain contains other subdomains. For example, the
purdue
subdomain can contain
econ, cs, and biol subdomains. At the deepest level of
hierarchy are the hosts, which are the leaves of the name space. A fully qualified host
name begins with the host’s canonical name and continues with a list of the
subdomains in the path from the host to the root of the name space. For example, the
fully qualified host name of the host
indigo in the div domain is
indigo.div.inc.com.
Figure A-1
shows the hierarchical structure of the DNS name space.