Topology Independent Fast Reroute Using Segment Routing

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Publisher: IETF
Doc Type: Standard
Pages: 23
Abstract: This document presents Topology Independent Loop-Free Alternate (TI-LFA) Fast Reroute (FRR), which is aimed at providing protection of node and Adjacency segments within the Segment Routing (SR) framework. This FRR behavior builds on proven IP FRR concepts being LFAs, Remote LFAs (RLFAs), and Directed Loop-Free Alternates (DLFAs). It extends these concepts to provide guaranteed coverage in any two-connected networks using a link-state IGP. An important aspect of TI-LFA is the FRR path selection approach establishing protection over the expected post-convergence paths from the Point of Local Repair (PLR), reducing the operational need to control the tie-breaks among various FRR options.
Publication Date: 2025-10-01
Status Note: Proposed Standard
DOI: 10.17487/RFC9855
Link: https://doi.org/10.17487/RFC9855
Author(s): Ahmed Bashandy
Stephane Litkowski
Clarence Filsfils
Pierre Francois
Bruno Decraene
Daniel Voyer
Keyword(s): TI-LFA, LFA, FRR, Recovery, Segment Routing, Convergence

Latest version of IETF RFC 9855

Document Versions — IETF RFC 9855

▶ IETF RFC 9855 (2025-10-01)

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Normative Reference(s)

IETF RFC 2119 [Active*]
IETF RFC 7916 [Active*]
IETF RFC 8174 [Active*]
IETF RFC 8402 [Active*]
IETF RFC 8660 [Active*]
IETF RFC 8754 [Active*]
IETF RFC 8986 [Active*]

Bibliographic Reference(s)

IETF.draft-bashandy-rtgwg-segment-routing-uloop-17 — I-D.bashandy-rtgwg-segment-routing-uloop EXTERNAL
IETF draft-bryant-ipfrr-tunnels-03 [Active*]
IETF RFC 5286 [Active*]
IETF RFC 5714 [Active*]
IETF RFC 5715 [Active*]
IETF RFC 6571 [Active*]
IETF RFC 6976 [Active*]
IETF RFC 7490 [Active*]
IETF RFC 8333 [Active*]
IETF RFC 8665 [Active*]
IETF RFC 8667 [Active*]
IETF RFC 9256 [Active*]
IETF RFC 9350 [Active*]

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IETF RFC 9855, Topology Independent Fast Reroute Using Segment Routing
doi: 10.17487/RFC9855
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Referenced By

IETF RFC 9960 [Active*]