Loop-Free Alternate (LFA) Applicability in Service Provider (SP) Networks
RFC 6571
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RFC - Informational
(June 2012; Errata)
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Last updated |
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2015-10-14
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Replaces |
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draft-filsfils-rtgwg-lfa-applicability
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IETF
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plain text
pdf
html
bibtex
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WG state
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Submitted to IESG for Publication
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Document shepherd |
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Alvaro Retana
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Shepherd write-up |
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Show
(last changed 2011-09-27)
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IESG state |
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RFC 6571 (Informational)
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Consensus Boilerplate |
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Unknown
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Telechat date |
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Responsible AD |
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Stewart Bryant
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IESG note |
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Alvaro Retana (alvaro.retana@hp.com) is the document shepherd.
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Send notices to |
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(None)
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Internet Engineering Task Force (IETF) C. Filsfils, Ed.
Request for Comments: 6571 Cisco Systems
Category: Informational P. Francois, Ed.
ISSN: 2070-1721 Institute IMDEA Networks
M. Shand
B. Decraene
France Telecom
J. Uttaro
AT&T
N. Leymann
M. Horneffer
Deutsche Telekom
June 2012
Loop-Free Alternate (LFA) Applicability
in Service Provider (SP) Networks
Abstract
In this document, we analyze the applicability of the Loop-Free
Alternate (LFA) method of providing IP fast reroute in both the core
and access parts of Service Provider networks. We consider both the
link and node failure cases, and provide guidance on the
applicability of LFAs to different network topologies, with special
emphasis on the access parts of the network.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6571.
Filsfils, et al. Informational [Page 1]
RFC 6571 LFA Applicability in SP Networks June 2012
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................3
2. Terminology .....................................................4
3. Access Network ..................................................6
3.1. Triangle ...................................................8
3.1.1. E1C1 Failure ........................................8
3.1.2. C1E1 Failure ........................................9
3.1.3. uLoop ...............................................9
3.1.4. Conclusion .........................................10
3.2. Full Mesh .................................................10
3.2.1. E1A1 Failure .......................................10
3.2.2. A1E1 Failure .......................................11
3.2.3. A1C1 Failure .......................................11
3.2.4. C1A1 Failure .......................................12
3.2.5. uLoop ..............................................12
3.2.6. Conclusion .........................................12
3.3. Square ....................................................13
3.3.1. E1A1 Failure .......................................13
3.3.2. A1E1 Failure .......................................14
3.3.3. A1C1 Failure .......................................15
3.3.4. C1A1 Failure .......................................15
3.3.5. Conclusion .........................................17
3.3.6. A Square Might Become a Full Mesh ..................17
3.3.7. A Full Mesh Might Be More Economical Than a
Square .............................................17
3.4. Extended U ................................................18
3.4.1. E1A1 Failure .......................................19
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