Observations on the Management of the Internet Address Space
RFC 1744

Document Type RFC - Informational (December 1994; No errata)
Author Geoff Huston 
Last updated 2013-03-02
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Network Working Group                                          G. Huston
Request for Comments: 1744                                        AARNet
Category: Informational                                    December 1994

                   Observations on the Management of
                       the Internet Address Space

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.


   This memo examines some of the issues associated with the current
   management practices of the Internet IPv4 address space, and examines
   the potential outcomes of these practices as the unallocated address
   pool shrinks in size.  Possible modifications to the management
   practices are examined, and potential outcomes considered.  Some
   general conclusions are drawn, and the relevance of these conclusions
   to the matter of formulation of address management policies for IPv6
   are noted.

1.  Introduction

   The area explicitly examined here is the allocatable globally unique
   IPv4 address space.  Explicitly this includes those address groups
   uniquely assigned from a single comprehensive address pool to
   specific entities which are then at liberty to assign individual
   address values within the address group to individual hosts.  The
   address group is handled by the technology as a single network

   At present these addresses are allocated to entities on a freely
   available, first-come, first-served allocation basis, within the
   scope of a number of administrative grounds which attempt to direct
   the allocation process to result in rational use of the space, and
   attempt to achieve a result of a level of equity of availability that
   is expressed in a sense of multi-national "regions" [1].

   In examining the current management policies in further detail it is
   useful to note that the IPv4 address space presents a number of
   attributes in common with other public space resources, and there are
   parallels in an economic analysis of this resource which include:

Huston                                                          [Page 1]
RFC 1744          Management of Internet Address Space     December 1994

    - the finite nature of the resource

      This attribute is a consequence of the underlying technology
      which has defined addressed entities in terms of a 32 bit address
      value.  The total pool is composed of 2**32 distinct values (not
      all of which are assignable to end systems).

    - the address space has considerable market value

      This valuation is a consequence of the availability and extensive
      deployment of the underlying Internet technology that allows
      uniquely addressed entities the capability to conduct direct end-
      to-end transactions with peer entities via the Internet.  The
      parameters of this valuation are also influenced by considerations
      of efficiency of use of the allocated space, availability of end
      system based internet technologies, the availability of Internet-
      based service providers and the resultant Internet market size.

    - address space management is a necessary activity

      Management processes are requires to ensure unique allocation and
      fair access to the resource, as well as the activity of continuing
      maintenance of allocation record databases.

   Increasing rates of Internet address allocation in recent years imply
   that the IPv4 address space is now a visibly finite resource, and
   current projections, assuming a continuation of existing demand for
   addresses predict unallocated address space exhaustion in the next 6
   - 12 years (rephrasing current interim projections from the IETF
   Address Lifetime Expectancy Working Group).  There are two derivative
   questions that arise from this prediction.  Firstly what is the
   likely outcome of unallocated address space exhaustion if it does
   occur, and secondly, are there corrective processes that may be
   applied to the current address management mechanisms that could allow
   both more equitable allocation and potentially extend the lifetime of
   the unallocated address space pool.  These two issues are considered
   in the following sections.

2. Outcomes of Unallocated Address Space Exhaustion - No change in
   current Address Management Policies

   As the pool of available addresses for allocation depletes, the
   initial anticipated outcome will be the inability of the available
   address pool to service large block address allocation requests.
   Such requests have already been phrased from various utility
   operators, and the demand for very large address blocks is likely to
   be a continuing feature of address pool management.  It is noted that
   the overall majority of the allocated address space is very

Huston                                                          [Page 2]
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