The domain name arpa is a top-level domain (TLD) in the Domain Name System (DNS) of the Internet. It is used predominantly for the management of technical network infrastructure. Prominent among such functions are the subdomains in-addr.arpa and ip6.arpa, which provide namespaces for reverse DNS lookup of IPv4 and IPv6 addresses, respectively.

The name originally was the acronym for the Advanced Research Projects Agency (ARPA), the funding organization in the United States that developed the ARPANET, the precursor of the Internet. It was the first domain defined for the network in preparation for a hierarchical naming system for the delegation of authority, autonomy, and responsibility. It was originally intended only to serve in a temporary function for facilitating the systematic naming of the ARPANET computers. However, it became practically difficult to remove the domain after infrastructural uses had been sanctioned. As a result, the name was redefined as the backronym Address and Routing Parameter Area.

Domain-name registrations in arpa are not possible, and new subdomains are infrequently added by the Internet Engineering Task Force.

Purpose

Each computer using the Internet Protocol is identified by a numerical IP address for identification and location addressing. Each host is also assigned a more memorable hostname, which often relates to the purpose or ownership of the host, and is used more conveniently in user interaction with network functions, such as when connecting to or accessing a resource. Originally, the mapping between names and addresses was a cumbersome mechanical process using lookup tables distributed as computer files between network administrators. The Domain Name System (DNS) solved this inefficiency by automating the lookup function with a hierarchical naming system using domain names. When a user requests a network service using a domain name, the protocol implementation (protocol stack) translates the name to an address that can be used to reach a remote host.

This naming function, often called forward resolution, was the original purpose of the top-level domain "ARPA". It was the first domain defined in the first naming system of the nascent Internet, and was supposed to be an initial container domain for all then-existing ARPANET hosts. The next stage of development of the naming architecture foresaw the establishment of specific domains for other purposes based on certain requirements. which prevent leaked queries for home.arpa from burdening the root servers.

History

The ARPANET, named for the Advanced Research Projects Agency (ARPA), was launched in 1969, and is considered the earliest predecessor of the Internet. The agency's name was adopted as the name for the first formal name space of the network after it had transitioned to TCP/IP networking in January 1983. The name was used as a naming suffix for all then-existing ARPANET hosts. Hierarchical domain-style names were intended to support delegation of responsibility and authority for adding future hosts to the network.

With the formal development of such a hierarchical naming system, the domain also became one of the inaugural members of a set of domain names for specific types of network members, namely com for commercial users, org for organizations, edu for educational institutions, gov for government entities, and mil for networks of the United States military.

It was expected that the use of arpa would be temporary and that the existing systems would be migrated to other domains. Arpa was retained for its long-standing purpose, but its full name was changed to the Address and Routing Parameter Area, making the zone name a backronym. Registrations of internet infrastructure services in .int made prior to this policy change, were optionally grandfathered in and not required to move to .arpa.

In March 2010, zone arpa was secured with digital signatures within the Domain Name System Security Extensions (DNSSEC).

Subdomains

Subdomains of arpa are created by resolution in the work groups of the Internet Engineering Task Force via the Request for Comments process, and are maintained by the Internet Assigned Numbers Authority (IANA). The DNS zone arpa has the following subdomains:

{| class=wikitable

! Domain || Purpose || Authority document (RFC)

|-

| 6tisch.arpa || For IPv6 over the Time Slotted Channel Hopping mode of IEEE 802.15.4 ||

|-

| as112.arpa || Sinking of DNS traffic for reverse IP address resolutions, misc. (see Blackhole server)||

|-

| e164.arpa || Mapping of E.164 numbers to Internet URIs ||

|-

| eap-noob.arpa || For the Nimble Out-Of-Band authentication method of the Extensible Authentication Protocol framework ||

|-

| home.arpa || Residential networking ||

|-

| in-addr.arpa || Mapping of IPv4 addresses to domain names ||

|-

| ip6.arpa || Mapping of IPv6 addresses to domain names ||

|-

| in-addr-servers.arpa || rowspan=2|Domains for authoritative DNS servers for the reverse lookup domains || rowspan=2|

|-

| ip6-servers.arpa

|-

| ipv4only.arpa || Detection of DNS64 availability and NAT64 prefix ||

|-

| iris.arpa || Locating Internet registry information services ||

|-

| ns.arpa || Domain for hosting authoritative DNS servers for the .arpa domain ||

|-

| resolver.arpa || Domain for discovery of designated DNS resolvers ||

|-

| service.arpa || For DNS-based service discovery over unicast ||

|-

| uri.arpa || rowspan=2|Resolution of URIs and URNs,<br>according to the Dynamic Delegation Discovery System || rowspan=2|

|-

| urn.arpa

|-

|}

References

(987)

  • arpa. zone file