Originally, .arpa was established as a temporary domain to serve as a transition mechanism for a set of host names in the [[ARPANET]] that were administered by [[DARPA]]. The host names were to be phased out after a replacement was created under the categorized TLDs which include [[.com]], [[.edu]], [[.mil]], [[.net]], [[.gov]] and [[.org]].<ref>[http://tools.ietf.org/rfc/rfc920.txt RFC 920]</ref> Although the initial plan for .arpa was to purge everything after the transition, the sub-domain in-addr.arpa remained active and it has been utilized for reverse [[DNS]] queries of [[IP Address|Internet Protocol addresses]].<ref>[http://tools.ietf.org/html/rfc3172#appendix-A RFC 3172]</ref> | Originally, .arpa was established as a temporary domain to serve as a transition mechanism for a set of host names in the [[ARPANET]] that were administered by [[DARPA]]. The host names were to be phased out after a replacement was created under the categorized TLDs which include [[.com]], [[.edu]], [[.mil]], [[.net]], [[.gov]] and [[.org]].<ref>[http://tools.ietf.org/rfc/rfc920.txt RFC 920]</ref> Although the initial plan for .arpa was to purge everything after the transition, the sub-domain in-addr.arpa remained active and it has been utilized for reverse [[DNS]] queries of [[IP Address|Internet Protocol addresses]].<ref>[http://tools.ietf.org/html/rfc3172#appendix-A RFC 3172]</ref> |