1. 简介 (Introduction)
本备忘录讨论了现有32位IPv4地址空间的地址分配策略，旨在节约地址空间并限制全局路由状态 (Global Routing State) 的增长率。本文档废除了RFC 1519中原始的无类别域间路由 (CIDR, Classless Inter-Domain Routing) 规范 [RFC1519]，并进行了修改，以澄清其引入的概念，并在十二年多之后，向互联网社区更新了所描述技术部署的结果。
This document obsoletes the original CIDR spec [RFC1519], with
changes made both to clarify the concepts it introduced and, after
more than twelve years, to update the Internet community on the
results of deploying the technology described.