Understanding address management hierarchy


Distribution Hierarchy

IANA allocates address space to APNIC to be redistributed throughout the Asia Pacific region.

APNIC allocates address space to IRs and also delegates to them the authority to make assignments and allocations. In some cases APNIC assigns address space to end users. National and Local IRs allocate and assign address space to their members and customer under the guidance of APNIC and according to various relevant policies and procedures.


Portable allocation

Allocated address space is address space that is distributed to IRs or other organizations for the purpose of subsequent distribution by them.

IRs include:

  • APNIC and other Regional Registries (RIRs);
    • RIRs are established under the authority of IANA to serve and represent large geographical regions. Their primary goal is to manage, distribute, and register public Internet address space within their respective regions. Current RIRs include: APNIC, RIPE, ARIN, LACNIC, AfriNIC.
  • National Internet Registries (NIRs);
    • A NIR primarily allocates address space to its members or constituents, which are generally organized at a national level. NIRs are expected to apply their policies and procedures fairly and equitably to all members of their constituency.
  • Local Internet Registries (LIRs)
    • A LIR is generally an ISP and may assign address space to its own network infrastructure and to users of its network services. LIR customers may be other downstream ISPs who further assign address space to their own customers.
Sub-allocations by LIRs

LIRs may sub-allocate address space to their downstream customers which are operating networks such as ISPs subject to the following conditions:

  • Sub-allocations are non-portable and must be returned to the LIR if the downstream customer ceases to receive connectivity from the LIR.
  • Sub-allocations are subject to the LIRs assignment window. Requests for sub-allocations that exceed the LIRs assignment window must first be referred to APNIC for second opinion approval.
  • The downstream customer that receives a sub-allocation from an LIR is not permitted to further sub-allocate the address space.
Portable assignments

Assigned address space is address space that is delegated to an ISP or end-user for specific use within the Internet infrastructure they operate. Assignments must only be made for specific documented purposes and may not be sub-assigned.


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