OSPF Bidirectional Forwarding Detection Strict-Mode
RFC 9355, “OSPF Bidirectional Forwarding Detection Strict-Mode”, is a Proposed Standard document published in February 2023 by K. Talaulikar, P. Psenak, A. Fu, M. Rajesh. It updates RFC 2328. The canonical text is published by the RFC Editor.
Abstract
This document specifies the extensions to OSPF that enable an OSPF router to signal the requirement for a Bidirectional Forwarding Detection (BFD) session prior to adjacency formation. Link-Local Signaling (LLS) is used to advertise the requirement for strict-mode BFD session establishment for an OSPF adjacency. If both OSPF neighbors advertise BFD strict-mode, adjacency formation will be blocked until a BFD session has been successfully established.
This document updates RFC 2328 by augmenting the OSPF neighbor state machine with a check for BFD session up before progression from Init to 2-Way state when operating in OSPF BFD strict-mode.
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 9355 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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