RFC 1627 (rfc1627) - Page 1 of 8
Network 10 Considered Harmful (Some Practices Shouldn't be Codified)
Alternative Format: Original Text Document
Network Working Group E. Lear
Request for Comments: 1627 Silicon Graphics, Inc.
Category: Informational E. Fair
Apple Computer, Inc.
D. Crocker
Silicon Graphics, Inc.
T. Kessler
Sun Microsystems, Inc.
July 1994
Network 10 Considered Harmful
(Some Practices Shouldn't be Codified)
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
SUMMARY
Re-use of Internet addresses for private IP networks is the topic of
the recent RFC 1597 [1]. It reserves a set of IP network numbers,
for (re-)use by any number of organizations, so long as those
networks are not routed outside any single, private IP network. RFC
1597 departs from the basic architectural rule that IP addresses must
be globally unique, and it does so without having had the benefit of
the usual, public review and approval by the IETF or IAB. This
document restates the arguments for maintaining a unique address
space. Concerns for Internet architecture and operations, as well as
IETF procedure, are explored.
INTRODUCTION
Growth in use of Internet technology and in attachments to the
Internet have taken us to the point that we now are in danger of
running out of unassigned IP network numbers. Initially, numbers
were formally assigned only when a network was about to be attached
to the Internet. This caused difficulties when initial use of IP
substantially preceded the decision and permission to attach to the
Internet. In particular, re-numbering was painful. The lesson that
we learned was that every IP address ought to be globally unique,
independent of its attachment to the Internet. This makes it
possible for any two network entities to communicate, no matter where
either might be located. This model is the result of a decades-long
evolution, through which the community realized how painful it can be
to convert a network of computers to use an assigned number after
Lear, Fair, Crocker & Kessler