IETF RFC 5737 PDF

Introduction

This document describes three IPv4 address blocks that are provided for use in documentation. The use of designated address ranges for documentation and examples reduces the likelihood of conflicts and confusion arising from the use of addresses assigned for some other purpose.

[RFC1166] reserves the first of the three address blocks, 192.0.2.0/24. The other two address blocks have recently been allocated for this purpose, primarily to ease the writing of examples involving addresses from multiple networks.

Other documentation ranges have been defined in the IETF, including the IPv6 documentation prefix [RFC3849] and example domain names [RFC2606]. Documentation also makes use of the ranges reserved in [RFC1918].