Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan

This specification has been revised 2 times since RFC 1338 (1992). Each document below formally obsoleted the one before it; the versions still in force are listed first.

Revision timeline

  1. RFC 1338 (1992)
  2. RFC 1519 (1993)
  3. RFC 4632 (2006)

Current version — implement against this

Superseded versions — historical reference only

This lineage is derived automatically from the “obsoletes” relationships recorded in the public RFC Editor index — no editorial judgement is applied to the ordering. The most recent document in the chain is RFC 4632 (August 2006).