BGP Link State Shortest Path First Routing
RFC 9815, “BGP Link State Shortest Path First Routing”, is a Proposed Standard document published in July 2025 by K. Patel, A. Lindem, S. Zandi, W. Henderickx. The canonical text is published by the RFC Editor.
Abstract
Many Massively Scaled Data Centers (MSDCs) have converged on simplified Layer 3 (L3) routing. Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for both fabric routing and Data Center Interconnect (DCI) routing. This document describes extensions to BGP for use with BGP Link State (BGP-LS) distribution and the Shortest Path First (SPF) algorithm. In doing this, it allows BGP to be efficiently used as both the underlay protocol and the overlay protocol in MSDCs.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 9815 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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