RFC 1918 (rfc1918) - Page 1 of 9


Address Allocation for Private Internets



Alternative Format: Original Text Document



Network Working Group                                         Y. Rekhter
Request for Comments: 1918                                 Cisco Systems
Obsoletes: 1627, 1597                                       B. Moskowitz
BCP: 5                                                    Chrysler Corp.
Category: Best Current Practice                            D. Karrenberg
                                                                RIPE NCC
                                                          G. J. de Groot
                                                                RIPE NCC
                                                                 E. Lear
                                                  Silicon Graphics, Inc.
                                                           February 1996


                Address Allocation for Private Internets

Status of this Memo

   This document specifies an Internet Best Current Practices for the
   Internet Community, and requests discussion and suggestions for
   improvements.  Distribution of this memo is unlimited.

1. Introduction

   For the purposes of this document, an enterprise is an entity
   autonomously operating a network using TCP/IP and in particular
   determining the addressing plan and address assignments within that
   network.

   This document describes address allocation for private internets. The
   allocation permits full network layer connectivity among all hosts
   inside an enterprise as well as among all public hosts of different
   enterprises. The cost of using private internet address space is the
   potentially costly effort to renumber hosts and networks between
   public and private.

2. Motivation

   With the proliferation of TCP/IP technology worldwide, including
   outside the Internet itself, an increasing number of non-connected
   enterprises use this technology and its addressing capabilities for
   sole intra-enterprise communications, without any intention to ever
   directly connect to other enterprises or the Internet itself.

   The Internet has grown beyond anyone's expectations. Sustained
   exponential growth continues to introduce new challenges.  One
   challenge is a concern within the community that globally unique
   address space will be exhausted. A separate and far more pressing
   concern is that the amount of routing overhead will grow beyond the



Rekhter, et al           Best Current Practice