Domain Name System

The Domain Name System (usually abbreviated to DNS) is a replicated distributed database which is used on the Internet to hold mappings from human-readable names (such as '.COM') to binary addresses. Before DNS, a file holding the mappings, the host table, was used, but that clearly was not going to scale.

The DNS is organized as a hierarchy; like file names in a hierarchical file system, a complete DNS name consists of a number of parts, each one of which selects one of the possible namespaces (sub-directories) at the next level down. The leaves of the tree usually name individual hosts.

Although the DNS has the capability to hold addresses for a number of different protocol suites, in general it now only hold addresses for the Internet Protocol.

See also

• Request for Comments

External links

• Domain Names - Concepts and Facilities (RFC-882 - November, 1983)
• Domain Names - Implementation and Specification (RFC-883 - November, 1983)
• Domain System Changes and Observations (RFC-973 - January, 1986)
• Domain Names - Concepts and Facilities (RFC-1034 - November, 1987)
• Domain Names - Implementation and Specification (RFC-1035 - November, 1987)