geoff@Fernwood.MPK.CA.US (Geoff Goodfellow) (03/16/89)
The US Domain The US domain is an official top-level domain in the Domain Name System (DNS) of the Internet community. It is registered with the Network Information Center at SRI International (SRI-NIC). The domain administrators are Jon Postel and Ann Westine at the Information Sciences Institute of the University of Southern California (USC-ISI). The US domain hierarchy is based on political geography, that is, the US domain is subdivided into states, then cities, and so on. Any computer in the United States may be registered in the US domain. Typical host names in the US domain are: VIXIE.SF.CA.US DOGWOOD.ATL.GA.US KILLER.DALLAS.TX.US HOLODEK.SANTA-CRUZ.CA.US GRIAN.CPS.ALTADENA.CA.US Because many computers in the United States are already registered in the COM, EDU, and other top level domains, relatively few computers are currently registered in the US domain. The computers that are registered are primarily owned by small companies or individuals (and often located in homes). It is expected than many more computers of all types and belonging to all sizes of organizations will be registered in the US domain. There is no change in the procedures for registration in, or operation of, other top-level domains such as COM, EDU, GOV, INT, MIL, NET, or ORG. These domains are not being moved under the US domain. Registration of a host in the US domain does not grant permission to use the Internet or its component networks. Any restrictions on sending mail through (or other use of) the Internet is independent of host registration in the US domain. Registration in the US domain does not allocate any IP address, or cause registration in HOSTS.TXT. Currently, the US domain and all of its subdivisions (that is, states and cities) are managed by the US Domain Administrator. At some time in the future the administration of individual states and cities will be transferred to appropriate responsible people. The administrator of a company or the organizer of a group (or "domain park") of users with individual hosts may coordinate the registration of the group by forwarding all the information for the group to the US Domain Administrator. The explicit specific information for each host must be provided. All fully qualified names must be unique. If a host is not directly on the Internet an MX record is required pointing to an Internet host for forwarding. The forwarding host must be directly on the Internet (that is, have an IP addresss), no "double MX-ing" is allowed. A group coordinator of, for example, the Computer Club in Chicago (CCC), could arrange to coordinate the registration of all the computers used by members of the club. The registered names might have the form: PC37.CCC.CHI.IL.US MX 10 CS.UOFC.EDU Only hosts on the Internet can act as forwarding hosts. Hosts on systems such as CSNET, UUCP, BITNET, must be registered with an Internet forwarding host. When registering a destination host in the US domain with an MX record, the requester is responsible for also registering the destination host with the administrator of the forwarding host. For example, when an messages is sent to "Susan@PC37.CCC.CHI.IL.US" it will be routed to the Internet host "CS.UOFC.EDU" as directed by the MX record. The host "CS.UOFC.EDU" must know some way of delivering the message to the host "PC37.CCC.CHI.IL.US" (uucp, slip, whatever). So the destination host (PC37.CCC.CHI.IL.US) must be known to (registered with) the forwarding host (CS.UOFC.EDU), as well as being registered in the DNS database. The administrator of the destination host must make an agreement with the administrator of the forwarding host for the forwarding service. This agreement must be in place before the request for registration is sent to the US Domain Administrator. A section of the DNS database is called a "zone". With careful coordination, a domain (like EDU) can be divided into several zones. This has been done for the EDU and COM domains to aid in the registration of hosts from the UUCP, CSNET and BITNET communities. If a host is registered in UUCP, BITNET, or CSNET zone (as something.EDU or something.COM), it need not be registered in the US domain, unless a geographical name (something.city.state.US) is desired. It is the policy that a computer must have a single primary name, so it should not be registered in both US and COM (or both US and EDU). It is possible to have "nicknames" for a brief period while a host name change is in progress. Wild card records are not currently allowed in the US domain. The US domain is currently supported by four name servers: VENERA.ISI.EDU, VAXA.ISI.EDU, HERCULES.CSL.SRI.COM, and NNSC.NSF.NET. There is no cost for registering a host in the US domain. For information on internet domains in general, see RFC-1034, Mockapetris, P., "Domain Names - Concepts and Facilities, and RFC-1035, Mockapetris, P., "Domain Names - Implementation and Specification. For more information about the US domain please contact Ann Westine at WESTINE@ISI.EDU.