A Border Gateway Protocol 4 (BGP-4)#

Yakov Rekhter (independent), Tony Li (HPE), Susan Hares (Huawei), John Scudder, Ed. (HPE) — IDR WG document

• Why: The once-in-a-generation rewrite of the BGP base specification — the document every BGP implementation will eventually be coded and tested against.
• What: draft-ietf-idr-bgp4-rfc4271bis-03 obsoletes RFC 4271 along with RFC 6286, 6608, 8212, and 9687, and subsumes the core of RFC 7606 (treat-as-withdraw error handling) into the base. Consolidation, not new machinery: restructured per-message and per-attribute error handling, the send-hold timer, typed NLRI parsing rules, an explicit route-resolvability condition in the decision process, and a roadmap distinguishing the "core extensions" (RFC 4760 multiprotocol, RFC 8654 extended messages) from the wider extension ecosystem.
• How: Full re-edit of RFC 4271 with a version-by-version change appendix and GitHub issue tracking; IDR milestone targets submission to the IESG as an Internet Standard by May 2027.
• Where applicable: All BGP implementations globally. Mature WG document in active revision; read it as the consolidation of two decades of errata and error-handling practice into one standard.