RE: Reserved Network Numbers

Geoff White [] writes:

Now for a brief excursion into the totally mundane.
Can anyone point me to the internet-draft/RFC that
specifies the "reserverd networks" (i.e. the class A,B, & C [sic]
network numbers that are considered "safe" (no-one should be routing them)
to use as test/intranet/private IP networks?

I believe you're looking for RFC 1918. Here's the header; document available at:

---document header---

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

   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.

James R. Saker Jr.
Network Media Division voice: 402.333.6233
Intellitek Corporation fax: 402.333.6432