Issues Associated with Designating Additional Private IPv4 Address Space

When a private network or internetwork grows very large, it is sometimes not possible to address all interfaces using private IPv4 address space because there are not enough addresses. This document describes the problems faced by those networks, the available options, and the issues involved in assigning a new block of private IPv4 address space. While this informational document does not make a recommendation for action, it documents the issues surrounding the various options that have been considered. This document is not an Internet Standards Track specification; it is published for informational purposes.