Hi Robert and Gyan, Thanks for your feedback! Your observation is correct that IGP Flex Algo could achieve the same. BGP DPF can be though as a BGP counterpart of IGP Flex Algo to some extent (though not precisely).
As explained in the “Introduction” section of this draft, BGP DPF is designed for the current IP fabric environment where EBGP is usually the only protocol used for routing. Section 5 of RFC 7938 explains why DC fabrics use EBGP as the sole routing protocol. Thanks, Kevin From: Gyan Mishra <[email protected]> Date: Tuesday, December 2, 2025 at 7:43 AM To: Robert Raszuk <[email protected]> Cc: idr@ietf. org <[email protected]>, lsr <[email protected]> Subject: [Idr] Re: Fwd: I-D Action: draft-wang-idr-dpf-00.txt I agree with Robert that you could use RFC 9502 IGP Flex Algo in IP networks to build disjoint planes as desired. You could also use SRv6 with IGP Flex Algo with SR RFC 9350 which uses IPv6 data plane and build your disjoint planes. Thanks Gyan On Tue, Dec 2, 2025 at 6:32 AM Robert Raszuk <[email protected]<mailto:[email protected]>> wrote: Hi, In respect to the subject draft ... why would you not use IGP Flexible Algorithm for it ? Are you going to port now years of work from IGP to BGP to achieve the same ? Besides, in a non-blocking fabric latency is really not a factor. So you want to logically partition it to make it blocking them worry about what travels on which such logical plane ? Is this a reasonable direction ? Thx, R. ---------- Forwarded message --------- From: <[email protected]<mailto:[email protected]>> Date: Mon, Dec 1, 2025 at 10:49 PM Subject: I-D Action: draft-wang-idr-dpf-00.txt To: <[email protected]<mailto:[email protected]>> Internet-Draft draft-wang-idr-dpf-00.txt is now available. Title: BGP Deterministic Path Forwarding (DPF) Authors: Kevin Wang Michal Styszynski Wen Lin Mahesh Subramaniam Thomas Kampa Diptanshu Singh Name: draft-wang-idr-dpf-00.txt Pages: 18 Dates: 2025-12-01 Abstract: Modern data center (DC) fabrics typically employ Clos topologies with External BGP (EBGP) for plain IPv4/IPv6 routing. While hop-by-hop EBGP routing is simple and scalable, it provides only a single best- effort forwarding service for all types of traffic. This single best-effort service might be insufficient for increasingly diverse traffic requirements in modern DC environments. For example, loss and latency sensitive AI/ML flows may demand stronger Service Level Agreements (SLA) than general purpose traffic. Duplication schemes which are standardized through protocols such as Parallel Redundancy Protocol (PRP) require disjoint forwarding paths to avoid single points of failure. Congestion avoidance may require more deterministic forwarding behavior. This document introduces BGP Deterministic Path Forwarding (DPF), a mechanism that partitions the physical fabric into multiple logical fabrics. Flows can be mapped to different logical fabrics based on their specific requirements, enabling deterministic forwarding behavior within the data center. The IETF datatracker status page for this Internet-Draft is: https://datatracker.ietf.org/doc/draft-wang-idr-dpf/<https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-wang-idr-dpf/__;!!NEt6yMaO-gk!EP_lEYmqbOUApQqqOz-ZuP9CsojS2gbvLvgQfxoYTXPXtS-0yjfv8ElqZwJBCRfOLFY6nymWoR5eJlshPeG9$> There is also an HTML version available at: https://www.ietf.org/archive/id/draft-wang-idr-dpf-00.html<https://urldefense.com/v3/__https://www.ietf.org/archive/id/draft-wang-idr-dpf-00.html__;!!NEt6yMaO-gk!EP_lEYmqbOUApQqqOz-ZuP9CsojS2gbvLvgQfxoYTXPXtS-0yjfv8ElqZwJBCRfOLFY6nymWoR5eJjgsy_TY$> Internet-Drafts are also available by rsync at: rsync.ietf.org::internet-drafts _______________________________________________ I-D-Announce mailing list -- [email protected]<mailto:[email protected]> To unsubscribe send an email to [email protected]<mailto:[email protected]> _______________________________________________ Idr mailing list -- [email protected]<mailto:[email protected]> To unsubscribe send an email to [email protected]<mailto:[email protected]>
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