Remote-LFA Node Protection and Manageability
RFC 8102
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Type |
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RFC - Proposed Standard
(March 2017; No errata)
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Last updated |
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2018-12-20
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Replaces |
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draft-psarkar-rtgwg-rlfa-node-protection
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Stream |
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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
(wg milestone:
Jul 2015 - Submit Remote LFA (n...
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Document shepherd |
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Jon Mitchell
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Shepherd write-up |
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Show
(last changed 2016-11-17)
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| IESG |
IESG state |
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RFC 8102 (Proposed Standard)
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Consensus Boilerplate |
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Yes
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Telechat date |
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Responsible AD |
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Alia Atlas
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Send notices to |
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"Jon Mitchell" <jrmitche@puck.nether.net>
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| IANA |
IANA review state |
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Version Changed - Review Needed
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IANA action state |
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No IANA Actions
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Internet Engineering Task Force (IETF) P. Sarkar, Ed.
Request for Comments: 8102 Arrcus, Inc.
Category: Standards Track S. Hegde
ISSN: 2070-1721 C. Bowers
Juniper Networks, Inc.
H. Gredler
RtBrick, Inc.
S. Litkowski
Orange
March 2017
Remote-LFA Node Protection and Manageability
Abstract
The loop-free alternates (LFAs) computed following the current
remote-LFA specification guarantees only link protection. The
resulting remote-LFA next hops (also called "PQ-nodes") may not
guarantee node protection for all destinations being protected by it.
This document describes an extension to the remote-loop-free-based IP
fast reroute mechanisms that specifies procedures for determining
whether or not a given PQ-node provides node protection for a
specific destination. The document also shows how the same procedure
can be utilized for the collection of complete characteristics for
alternate paths. Knowledge about the characteristics of all
alternate paths is a precursor to applying the operator-defined
policy for eliminating paths not fitting the constraints.
Status of This Memo
This is an Internet Standards Track document.
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). Further information on
Internet Standards is available in Section 2 of RFC 7841.
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/rfc8102.
Sarkar, et al. Standards Track [Page 1]
RFC 8102 R-LFA Node Protection and Manageability March 2017
Copyright Notice
Copyright (c) 2017 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.
Sarkar, et al. Standards Track [Page 2]
RFC 8102 R-LFA Node Protection and Manageability March 2017
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Node Protection with Remote-LFA . . . . . . . . . . . . . . . 5
2.1. The Problem . . . . . . . . . . . . . . . . . . . . . . . 5
2.2. Additional Definitions . . . . . . . . . . . . . . . . . 7
2.2.1. Link-Protecting Extended P-Space . . . . . . . . . . 7
2.2.2. Node-Protecting Extended P-Space . . . . . . . . . . 7
2.2.3. Q-Space . . . . . . . . . . . . . . . . . . . . . . . 8
2.2.4. Link-Protecting PQ-Space . . . . . . . . . . . . . . 8
2.2.5. Candidate Node-Protecting PQ-Space . . . . . . . . . 8
2.2.6. Cost-Based Definitions . . . . . . . . . . . . . . . 8
2.2.6.1. Link-Protecting Extended P-Space . . . . . . . . 9
2.2.6.2. Node-Protecting Extended P-Space . . . . . . . . 9
2.2.6.3. Q-Space . . . . . . . . . . . . . . . . . . . . . 10
2.3. Computing Node-Protecting R-LFA Path . . . . . . . . . . 10
2.3.1. Computing Candidate Node-Protecting PQ-Nodes for
Primary Next Hops . . . . . . . . . . . . . . . . . . 10
2.3.2. Computing Node-Protecting Paths from PQ-Nodes to
Destinations . . . . . . . . . . . . . . . . . . . . 12
2.3.3. Computing Node-Protecting R-LFA Paths for
Destinations with Multiple Primary Next-Hop Nodes . . 14
2.3.4. Limiting Extra Computational Overhead . . . . . . . . 18
3. Manageability of Remote-LFA Alternate Paths . . . . . . . . . 19
3.1. The Problem . . . . . . . . . . . . . . . . . . . . . . . 19
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