Legacy Resource History


Internet Protocol (IP) address space was originally administered by Jon Postel via a function known as the Internet Assigned Numbers Authority (IANA) (RFC 1060). Early on, Internet number resources were allocated liberally to any organization that fulfilled the simple request requirements without formal legal agreement. As the Internet grew globally, the administrative mechanisms of Internet number resource distribution could not continue to be managed efficiently by a single individual or organization. This led to distribution of the registration and management responsibilities and ultimately to the formation of the Regional Internet Registry (RIR) system (RFC 1366).

When ARIN (one of the five RIRs) was formed in December 1997, it was tasked with the administration and management of the entire database of IPv4 addresses and ASNs that were not administered by either of the two existing European (RIPE NCC) and Asia-Pacific (APNIC) regional registries. These previously-assigned resources are often referred to as legacy number resources. At its formation, the ARIN Board of Trustees decided that ARIN would provide registration services for these legacy number resources without requiring the original resource holders to enter into a registration services agreement or pay service fees.

Early Registration Transfer Project

As the RIR system matured, it was decided that the interests of the legacy resource holders would be best served by having these resources administered by the RIR operating in the region where the Internet number resources were being used. The outcome of consultations with the community led to the development of the Early Registration Transfer (ERX) project, whereby early registrations were moved from the ARIN database into the appropriate RIR databases beginning in 2003. These number resources are now administered by the respective RIR in the region where the resources are being used.

LRSA Statistics

For a number of years, ARIN tracked and reported on the adoption of the Legacy RSA. The last published report on this is available on the website.