.arpa
arpa | |
---|---|
Introduced | 1985 |
Type | Infrastructure domain |
status | active |
Registrar | IANA |
sponsor | Internet Architecture Board |
Intended use | Address and routing parameter area: Internet infrastructure such as reverse IP search. |
restrictions | No domain registration possible, new subdomains are rarely added |
structure | Second-level domains provide special namespaces for database functions |
document | RFC 3172 |
Dispute Resolution Policy | No |
website | IANA .arpa Info |
The domain arpa is a top-level domain in the domain name system (DNS) of the Internet . It is used exclusively for technical infrastructure purposes. Although the name originally an acronym for Advanced Research Projects Agency (ARPA) was the research agency in the United States, which the predecessor of the Internet ( ARPANET developed) is he now to address and routing parameter area (Address- and routing parameters -Area).
arpa
contains, among others, the domains in-addr.arpa
and ip6.arpa
, which are used for reverse DNS lookups of IPv4 or IPv6 addresses.
history
The arpa
top-level domain was the first domain to be set up in the Domain Name System (DNS). It was originally intended as a temporary domain to facilitate the transition from the ARPANET hostname conventions to the host table distribution methods of DNS. The ARPANET was the predecessor of the Internet, which was provided by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense . Was considered the domain name system introduced in 1985, ARPANET host names were initially converted into DNS-based name by the arpa
-Domain label has been added to the end of the existing host name, by a point separated. This form of domain name was then rapidly phased out by being replaced by the newly introduced categorized top-level domains.
After serving arpa
its transitional purpose, it turned out that it is impractical to delete the domain, since in-addr.arpa was used for the inverted DNS search of IP addresses . For example, the assignment of the IP address 145.97.39.155 to a host name is accomplished by executing a DNS query for a pointer of the domain name 155.39.97.145.in-addr.arpa.
It was planned that new infrastructure databases would be created in the top-level domain int
. However, in May 2000 this requirement was lifted and it was decided that arpa
for this purpose it should be retained. int
should only be used by international organizations. In accordance with this new specification, Area (a backronym ) arpa
now stands for Address and Routing Parameter .
Second-level domains
The following second-level domains are currently active:
domain | Intended use | RFC standard |
---|---|---|
as112.arpa |
For addressing blackhole DNS servers that intercept DNS queries about non-existent addresses (e.g. reverse DNS queries about private IP addresses ) | RFC 7535 |
e164.arpa |
ENUM For translating telephone numbers into Internet addresses | RFC 6116 |
home.arpa |
DNS zone for non-globally unique private local domains | RFC 8375 |
in-addr.arpa |
Reverse search of IPv4 addresses for DNS names | RFC 1035 |
in-addr-servers.arpa |
Zone for the zone's DNS servers in-addr.arpa
|
RFC 5855 |
ip6.arpa |
Reverse lookup of IPv6 addresses for DNS names | RFC 3152 |
ip6-servers.arpa |
Zone for the zone's DNS servers ip6.arpa
|
RFC 5855 |
ipv4only.arpa |
Detecting the presence of DNS64 and learning the IPv6 prefix used | RFC 7050 |
iris.arpa |
For the use of Cross Registry Information Service Protocol (CRISP) | RFC 4698 |
uri.arpa |
For the dynamic determination of Uniform Resource Identifier (URI) addressing schemes | RFC 3405 |
urn.arpa |
For the dynamic determination of Uniform Resource Name (URN) addressing schemes |
Web links
- .ARPA Zone Management at IANA
- .arpa Zone File