.arpa

A top-level domain used only for internet infrastructure, not for ordinary websites. Its best known branches, in-addr.arpa and ip6.arpa, hold the records that turn IP addresses (glossary)IP Internet Protocol The internet's basic rules for sending data, using numeric addresses for every connected device. Full definition of IP back into names. IANA (glossary)IANA Internet Assigned Numbers Authority The functions that coordinate the root zone, IP addresses and protocol numbers. Full definition of IANA manages it with the internet technical community. The name stands for Address and Routing Parameter Area.