This document describes a Cisco Systems protocol that can be used to
detect and disable unidirectional Ethernet fiber or copper links
caused for instance by mis-wiring of fiber strands, interface
malfunctions, media converters' faults, etc. It operates at Layer 2
in conjunction with IEEE 802.3's existing Layer 1 fault detection
This document explains the protocol objectives and applications,
illustrates the specific premises the protocol was based upon and
describes the protocol architecture and related deployment issues, to
serve as a possible base for future standardization.
Working Group Summary
This document is not the product of any IETF Working Group. It was
submitted directly to the RFC Editor by the authors.
This document was reviewed by Joel Halpern and by the RFC Editor.
At the request of the RFC Editor, the author changed the title and
Abstract to make clear that this is a Cisco protocol, not an IETF
This RFC is not a candidate for any level of Internet Standard.
The IETF disclaims any knowledge of the fitness of this RFC for
any purpose and in particular notes that the decision to publish
is not based on IETF review for such things as security,
congestion control, or inappropriate interaction with deployed
protocols. The RFC Editor has chosen to publish this document at
its discretion. Readers of this document should exercise caution
in evaluating its value for implementation and deployment. See
RFC 3932 for more information.