RIFT: Routing in Fat Trees
RFC 9692, “RIFT: Routing in Fat Trees”, is a Proposed Standard document published in April 2025 by T. Przygienda, J. Head, A. Sharma, P. Thubert, B. Rijsman, D. Afanasiev. The canonical text is published by the RFC Editor.
Abstract
This document defines a specialized, dynamic routing protocol for Clos, fat tree, and variants thereof. These topologies were initially used within crossbar interconnects and consequently router and switch backplanes, but their characteristics make them ideal for constructing IP fabrics as well. The protocol specified by this document is optimized towards the minimization of control plane state to support very large substrates as well as the minimization of configuration and operational complexity to allow for a simplified deployment of said topologies.
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 9692 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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