rfc1480.txt
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Network Working Group A. Cooper
Request for Comments: 1480 J. Postel
Obsoletes: 1386 June 1993
The US Domain
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard. Distribution of this memo is
unlimited.
Table of Contents
1. Introduction ................................................ 2
1.1 The Internet Domain Name System......................... 2
1.2 Top-Level Domains....................................... 3
1.3 The US Domain .......................................... 4
2. Naming Structure ............................................ 4
2.1 State Codes ............................................ 8
2.2 Locality Names.......................................... 8
2.3 Schools ................................................ 10
2.4 State Agencies.......................................... 15
2.5 Federal Agencies ....................................... 15
2.6 Distributed National Institutes......................... 15
2.7 General Independent Entities............................ 16
2.8 Examples of Names....................................... 17
3. Registration ................................................ 20
3.1 Requirements ........................................... 20
3.2 Direct Entries ......................................... 21
3.2.1 IP-Hosts............................................. 21
3.2.2 Non-IP Hosts ........................................ 21
3.3 Delegated Subdomains ................................... 24
3.3.1 Delegation Requirement............................... 26
3.3.2 Delegation Procedures ............................... 28
3.3.3 Subdomain Contacts................................... 29
4. Database Information......................................... 30
4.1 Name Servers ........................................... 30
4.2 Zone files ............................................. 30
4.3 Resource Records ....................................... 31
4.3.1 "A" Records ......................................... 32
4.3.2 CNAME Records ....................................... 32
4.3.3 MX Records .......................................... 33
4.3.4 HINFO Records ....................................... 33
4.3.5 PTR Records ......................................... 33
4.4 Wildcards .............................................. 34
5. References .................................................. 35
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RFC 1480 The US Domain June 1993
6. Security Considerations ..................................... 35
7. Authors' Addresses .......................................... 36
Appendix-I: US Domain Names BNF................................. 37
Appendix-II: US Domain Questionnaire ............................ 42
1. INTRODUCTION
1.1 The Internet Domain Name System
The Domain Name System (DNS) provides for the translation between
hostnames and addresses. Within the Internet, this means translating
from a name such as "venera.isi.edu", to an IP address such as
"128.9.0.32". The DNS is a set of protocols and databases. The
protocols define the syntax and semantics for a query language to ask
questions about information located by DNS-style names. The
databases are distributed and replicated. There is no dependence on
a single central server, and each part of the database is provided in
at least two servers.
The assignment of the 32-bit IP addresses is a separate activity. IP
addresses are delegated by the central Internet Registry to regional
authorities (such as the RIPE NCC for Europe) and the network
providers.
To have a network number assigned please contact your network service
provider or regional registration authority. To determine who this
is (or as a last resort), you can contact the central Internet
Registry at Hostmaster@INTERNIC.NET.
In addition to translating names to addresses for hosts that are on
the Internet, the DNS provides for registering DNS-style names for
other hosts reachable (via electronic mail) through gateways or mail
relays. The records for such name registrations point to an Internet
host (one with an IP address) that acts as a mail forwarder for the
registered host. For example, the host "bah.rochester.ny.us" is
registered in the DNS with a pointer to the mail relay
"relay1.uu.net". This type of pointer is called an MX record.
This gives electronic mail users a uniform mail addressing syntax and
avoids making users aware of the underlying network boundaries.
The reason for the development of the domain system was growth in the
Internet. The hostname to address mappings were maintained by the
InterNIC in a single file, called HOSTS.TXT, which was FTP'd by all
the hosts on the Internet. The network population was changing in
character. The time-share 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
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RFC 1480 The US Domain June 1993
had to wait for the NIC to make changes in HOSTS.TXT to make the
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 service. The idea of a hierarchical name space,
with the hierarchy roughly corresponding to organizational structure,
and names using "." as the character to mark the boundary between
hierarchy levels was developed. A design using a distributed
database and generalized resources was implemented.
The DNS provides standard formats for resource data, standard methods
for querying the database, and standard methods for name servers to
refresh local data from other name servers.
1.2 Top-Level Domains
The top-level domains in the DNS are EDU, COM, GOV, MIL, ORG, INT,
and NET, and all the 2-letter country codes from the list of
countries in ISO-3166. The establishment of new top-level domains is
managed by the Internet Assigned Numbers Authority (IANA). The IANA
may be contacted at IANA@ISI.EDU.
Even though the original intention was that any educational
institution anywhere in the world could be registered under the EDU
domain, in practice, it has turned out with few exceptions, only
those in the United States have registered under EDU, similarly with
COM (for commercial). In other countries, everything is registered
under the 2-letter country code, often with some subdivision. For
example, in Korea (KR) the second level names are AC for academic
community, CO for commercial, GO for government, and RE for research.
However, each country may go its own way about organizing its domain,
and many have.
There are no current plans of putting all of the organizational
domains EDU, GOV, COM, etc., under US. These name tokens are not
used in the US Domain to avoid confusion.
Currently, only four year colleges and universities are being
registered in the EDU domain. All other schools are being registered
in the US Domain.
There are also concerns about the size of the other top-level domains
(especially COM) and ideas are being considered for restructuring.
Other names sometimes appear as top-level domain names. Some people
have made up names in the DNS-style without coordinating or
registering with the DNS management. Some names that typically
appear are BITNET, UUCP, and two-letter codes for continents, such as
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RFC 1480 The US Domain June 1993
"NA" for North America (this conflicts with the official Internet
code for Namibia).
For example, the DNS-style name "KA7EEJ.CO.USA.NA" is used in the
amateur radio network. These addresses are never supposed to show up
on the Internet but they do occasionally. The amateur radio network
people created their own naming scheme, and it interferes sometimes
with Internet addresses.
1.3 The US Domain
The US Domain is an official top-level domain in the DNS of the
Internet community. The domain administrators are Jon Postel and Ann
Westine Cooper at the Information Sciences Institute of the
University of Southern California (USC-ISI).
US is the ISO-3166 2-letter country code for the United States and
thus the US Domain is established as a top-level domain and
registered with the InterNIC the same way other country domains are.
Because organizations in the United States have registered primarily
in the EDU and COM domains, little use was initially made of the US
domain. In the past, the computers registered in the US Domain were
primarily owned by small companies or individuals with computers at
home. However, the US Domain has grown and currently registers hosts
in federal government agencies, state government agencies, K12
schools, community colleges, technical/vocational schools, private
schools, libraries, city and county government agencies, to name a
few.
Initially, the administration of the US Domain was managed solely by
the Domain Registrar. However, due to the increase in registrations,
administration of subdomains is being delegated to others.
Any computer in the United States may be registered in the US Domain.
2. NAMING STRUCTURE
The US Domain hierarchy is based on political geography. The basic
name space under US is the state name space, then the "locality" name
space, (like a city, or county) then organization or computer name
and so on.
For example:
BERKELEY.CA.US
PORTLAND.WA.US
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RFC 1480 The US Domain June 1993
There is of course no problem with running out of names.
The things that are named are individual computers.
If you register now in one city and then move, the database can be
updated with a new name in your new city, and a pointer can be set up
from your old name to your new name. This type of pointer is called
a CNAME record.
The use of unregistered names is not effective and causes problems
for other users. Inventing your own name and using it without
registering is not a good idea.
In addition to strictly geographically names, some special names are
used, such as FED, STATE, AGENCY, DISTRICT, K12, LIB, CC, CITY, and
COUNTY. Several new name spaces have been created, DNI, GEN, and
TEC, and a minor change under the "locality" name space was made to
the existing CITY and COUNTY subdomains by abbreviating them to CI
and CO. A detailed description follows.
Below US, Parallel to States:
-----------------------------
"FED" - This branch may be used for agencies of the federal
government. For example: <org-name>.<city>.FED.US
"DNI" - DISTRIBUTED NATIONAL INSTITUTES - The "DNI" branch was
created directly under the top-level US. This branch is to be used
for distributed national institutes; organizations that span state,
regional, and other organizational boundaries; that are national in
scope, and have distributed facilities. For example:
<org-name>.DNI.US.
Name Space Within States:
------------------------
"locality" - cities, counties, parishes, and townships. Subdomains
under the "locality" would be like CI.<city>.<state>.US,
CO.<county>.<state>.US, or businesses. For example:
Petville.Marvista.CA.US.
"CI" - This branch is used for city government agencies and is a
subdomain under the "locality" name (like Los Angeles). For example:
Fire-Dept.CI.Los-Angeles.CA.US.
"CO" - This branch is used for county government agencies and is a
subdomain under the "locality" name (like Los Angeles). For example:
Fire-Dept.CO.San-Diego.CA.US.
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RFC 1480 The US Domain June 1993
"K12" - This branch may be used for public school districts. A
special name "PVT" can be used in the place of a school district name
for private schools. For example: <school-name>.K12.<state>.US and
<school-name>.PVT.K12.<state>.US.
"CC" - COMMUNITY COLLEGES - This branch was established for all state
wide community colleges. For example: <school-name>.CC.<state>.US.
"TEC" - TECHNICAL AND VOCATIONAL SCHOOLS - The branch "TEC" was
established for technical and vocational schools and colleges. For
example: <school-name>.TEC.<state>.US.
"LIB" - LIBRARIES (STATE, REGIONAL, CITY, COUNTY) - This branch may
be used for libraries only. For example: <lib-name>.LIB.<state>.US.
"STATE" - This branch may be used for state government agencies. For
example: <org-name>.STATE.<state>.US.
"GEN" - GENERAL INDEPENDENT ENTITY - This branch is for the things
that don't fit easily into any other structure listed -- things that
might fit in to something like ORG at the top-level. It is best not
to use the same keywords (ORG, EDU, COM, etc.) that are used at the
top-level to avoid confusion. GEN would be used for such things as,
state-wide organizations, clubs, or domain parks. For example:
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