11. Status Updates to CIDR Documents

11. Status Updates to CIDR Documents

This memo renders obsolete and requests re-classification as Historic

the following RFCs describing CIDR usage and deployment:

o RFC 1467: Status of CIDR Deployment in the Internet

This Informational RFC described the status of CIDR deployment in

1993. As of 2005, CIDR has been thoroughly deployed, so this

status note only provides a historical data point.

o RFC 1481: IAB Recommendation for an Intermediate Strategy to

Address the Issue of Scaling

This very short Informational RFC described the IAB's endorsement

of the use of CIDR to address scaling issues. Because the goal of

RFC 1481 has been achieved, it is now only of historical value.

o RFC 1482: Aggregation Support in the NSFNET Policy-Based Routing

Database

This Informational RFC describes plans for support of route

aggregation, as specified by CIDR, on the NSFNET. Because the

NSFNET has long since ceased to exist and CIDR has been

ubiquitously deployed, RFC 1482 now only has historical relevance.

o RFC 1517: Applicability Statement for the Implementation of

Classless Inter-Domain Routing (CIDR)



This Standards Track RFC described where CIDR was expected to be

required and where it was expected to be (strongly) recommended.

With the full deployment of CIDR on the Internet, situations where

CIDR is not required are of only historical interest.

o RFC 1518: An Architecture for IP Address Allocation with CIDR

This Standards Track RFC discussed routing and address aggregation

considerations at some length. Some of these issues are

summarized in this document in section Section 3.1. Because

address assignment policies and procedures now reside mainly with

the RIRs, it is not appropriate to try to document those practices

in a Standards Track RFC. In addition, [RFC3221] also describes

many of the same issues from point of view of the routing system.

o RFC 1520: Exchanging Routing Information Across Provider

Boundaries in the CIDR Environment

This Informational RFC described transition scenarios where CIDR

was not fully supported for exchanging route information between

providers. With the full deployment of CIDR on the Internet, such

scenarios are no longer operationally relevant.

o RFC 1817: CIDR and Classful Routing

This Informational RFC described the implications of CIDR

deployment in 1995; it notes that formerly-classful addresses were

to be allocated using CIDR mechanisms and describes the use of a

default route for non-CIDR-aware sites. With the full deployment

of CIDR on the Internet, such scenarios are no longer

operationally relevant.

o RFC 1878: Variable Length Subnet Table For IPv4

This Informational RFC provided a table of pre-calculated subnet

masks and address counts for each subnet size. With the

incorporation of a similar table into this document (see Section

3.1), it is no longer necessary to document it in a separate RFC.

o RFC 2036: Observations on the use of Components of the Class A

Address Space within the Internet

This Informational RFC described several operational issues

associated with the allocation of classless prefixes from

previously-classful address space. With the full deployment of

CIDR on the Internet and more than half a dozen years of

experience making classless prefix allocations out of historical

"Class A" address space, this RFC now has only historical value.

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