The Internet Registry System



The Internet Assigned Numbers Authority has authority over all number spaces used in the Internet. This includes IP address space. IANA allocates public Internet address space to Regional Internet Registries according to their established needs.

Regional Internet Registries

RIRs operate in large, geopolitical regions that are continental in scope. Currently, there are five RIRs established:

  • AFRINIC, serving Africa.
  • ARIN, serving: Canada, many Caribbean and North Atlantic islands, and the United States.
  • LACNIC, serving South America and the Caribbean.
  • APNIC, serving the Asia Pacific region.
  • RIPE NCC, serving Europe, Central Asia and the Middle East.

The duties of an RIR include the co-ordination and representation of the members in its region. Additional RIRs may be established in the future, although their number will remain relatively low.

Local Internet Registries

LIRs are established under the authority of an RIR. LIRs are typically operated by Internet Service Providers and serve the customers of those ISPs as well as the customers of smaller ISPs that are connected to the rest of the Internet through the larger ISP. Other organisations such as large Enterprises can also operate LIRs. Much of this document is concerned with the responsibility of the LIR in the assignment process. In some cases, the LIR assigning the address space is not run by the ISP that will provide connectivity. It is important to note that the maintenance of the administrative information regarding the assigned address space is the responsibility of the LIR that makes the assignment and not of the ISP providing the connectivity. Furthermore, only RIRs and LIRs can hold address allocations.

End User

An entity that uses IP address space for its network only and does not provide IP/ASN services to customers. Strictly speaking, End Users are not part of the Internet Registry System. They do, however, play an important role with respect to the goals defined above. In order to achieve the conservation goal, for example, End Users should plan their networks to use a minimum amount of address space. They must document their addressing and deployment plans to the LIR and furnish any additional information required by the LIR for making assignment decisions. To achieve the aggregation goal, an End User should choose an appropriate LIR. End Users should be aware that changing ISPs may require replacing addresses in their networks. Finally, End Users must provide and update registration data for the address space assigned to them.


In addition to these key players in the Internet Registry System, there are often consultants who set up and manage networks for End Users. The consultants may be the people actually submitting a request for address space to an LIR on behalf of an End User. We refer to the person making the request for an End User as a requester, whether that person is employed by the organisation, or is simply acting on behalf of the organisation with respect to the address space request.

Comments are closed.