RFC 2036 (rfc2036) - Page 1 of 9

Observations on the use of Components of the Class A Address Space within the Internet

Network Working Group                                          G. Huston
Request for Comments: 2036                              Telstra Internet
Category: Informational                                     October 1996


          Observations on the use of Components of the Class A
                   Address Space within the Internet

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.

Abstract

   This document is a commentary on the recommendation that IANA
   commence allocation of the presently unallocated components of the
   Class A address space to registries, for deployment within the
   Internet as class-less address blocks.

   The document examines the implications for service providers and end
   clients within this environment. The document notes the major
   conclusion that widespread adoption of class-less routing protocols
   is required, within a relatively rapid timeframe for this
   recommendation to be effective.

Introduction

   The Address Lifetime Expectancy (ALE) Working Group of the IETF has
   recorded the allocation of Internet addresses from the unallocated
   address pool. ALE has noted that the existing practice of drawing
   addresses from the Class C space (192/3 address prefix) will result
   in near to medium term exhaustion of this section of the unallocated
   address pool. The largest remaining pool is in the Class A space,
   where some 25% of Internet addresses (the upper half of the Class A
   space) remain, to date, unallocated.

   This document is a commentary on the potential recommendation that
   the Internet Assigned Numbers Authority (IANA), through delegated
   registries, commence allocation of the presently unallocated
   components of the Class A  address space to registries, for
   deployment within the Internet through the mechanism of allocation of
   class-less address prefixes.

   The deployment of class-less address prefixes from the Class A space
   within the Internet will require some changes to the routing
   structure within Internet component network domains. The motivation



Huston                       Informational