RFC 9855: Topology Independent Fast Reroute Using Segment Routing
In plain English — editorial summary, not part of the RFC
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.
Document record
- Document ID
- RFC9855
- Published
- October 2025
- Authors
- A. Bashandy; S. Litkowski; C. Filsfils; P. Francois; B. Decraene; D. Voyer
- Status
- PROPOSED STANDARD
- Stream
- IETF
- Area
- rtg
- Pages
- 23
- Also known as
- —
Topics
Related documents
Ranked automatically by shared keywords, IETF area and stream — not by editorial selection.
- RFC 7916Operational Management of Loop-Free AlternatesCurrent
July 2016
- RFC 7812An Architecture for IP/LDP Fast Reroute Using Maximally Redundant Trees (MRT-FRR)Current
June 2016
- RFC 7811An Algorithm for Computing IP/LDP Fast Reroute Using Maximally Redundant Trees (MRT-FRR)Current
June 2016
- RFC 5286Basic Specification for IP Fast Reroute: Loop-Free AlternatesUpdated
September 2008
- RFC 9722Fast Recovery for EVPN Designated Forwarder ElectionCurrent
May 2025
- RFC 8400Extensions to RSVP-TE for Label Switched Path (LSP) Egress ProtectionCurrent
June 2018
- RFC 8355Resiliency Use Cases in Source Packet Routing in Networking (SPRING) NetworksCurrent
March 2018
- RFC 8104Pseudowire (PW) Endpoint Fast Failure ProtectionCurrent
March 2017
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