Domain names - concepts and facilities (RFC1034)
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
This RFC introduces domain style names, their use for Internet mail and host address support, and the protocols and servers used to implement domain name facilities.
Network Working Group P. Mockapetris
Request for Comments: 1034 ISI
Obsoletes: RFCs 882, 883, 973 November 1987
DOMAIN NAMES - CONCEPTS AND FACILITIES
1. STATUS OF THIS MEMO
This RFC is an introduction to the Domain Name System (DNS), and omits
many details which can be found in a companion RFC, "Domain Names -
Implementation and Specification" [RFC-1035]. That RFC assumes that the
reader is familiar with the concepts discussed in this memo.
A subset of DNS functions and data types constitute an official
protocol. The official protocol includes standard queries and their
responses and most of the Internet class data formats (e.g., host
However, the domain system is intentionally extensible. Researchers are
continuously proposing, implementing and experimenting with new data
types, query types, classes, functions, etc. Thus while the components
of the official protocol are expected to stay essentially unchanged and
operate as a production service, experimental behavior should always be
expected in extensions beyond the official protocol. Experimental or
obsolete features are clearly marked in these RFCs, and such information
should be used with caution.
The reader is especially cautioned not to depend on the values which
appear in examples to be current or complete, since their purpose is
primarily pedagogical. Distribution of this memo is unlimited.
This RFC introduces domain style names, their use for Internet mail and
host address support, and the protocols and servers used to implement
domain name facilities.
2.1. The history of domain names
The impetus for the development of the domain system was growth in the
- Host name to address mappings were maintained by the Network
Information Center (NIC) in a single file (HOSTS.TXT) which
was FTPed by all hosts [RFC-952, RFC-953]. The total network
bandwidth consumed in distributing a new version by this
scheme is proportional to the square of the number of hosts in
the network, and even when multiple levels of FTP are used,
the outgoing FTP load on the NIC host is considerable.
Explosive growth in the number of hosts didn't bode well for
- The network population was also changing in character. The
timeshared hosts that made up the original ARPANET were being
replaced with local networks of workstations. Local
organizations were administering their own names and
addresses, but had to wait for the NIC to change HOSTS.TXT to
make changes visible to the Internet at large. Organizations
also wanted some local structure on the name space.
- The applications on the Internet were getting more
sophisticated and creating a need for general purpose name
The result was several ideas about name spaces and their management
[IEN-116, RFC-799, RFC-819, RFC-830]. The proposals varied, but...