SPF Back-off algorithm for link state IGPs
draft-ietf-rtgwg-backoff-algo-05

Document Type Active Internet-Draft (rtgwg WG)
Last updated 2017-10-16 (latest revision 2017-05-02)
Stream IETF
Intended RFC status (None)
Formats plain text xml pdf html bibtex
Reviews
Stream WG state WG Document
Doc Shepherd Follow-up Underway
Document shepherd Uma Chunduri
IESG IESG state I-D Exists
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to Uma Chunduri <uma.chunduri@huawei.com>
Network Working Group                                        B. Decraene
Internet-Draft                                                    Orange
Intended status: Standards Track                            S. Litkowski
Expires: November 1, 2017                        Orange Business Service
                                                              H. Gredler
                                                             RtBrick Inc
                                                               A. Lindem
                                                           Cisco Systems
                                                             P. Francois

                                                               C. Bowers
                                                  Juniper Networks, Inc.
                                                          April 30, 2017

               SPF Back-off algorithm for link state IGPs
                    draft-ietf-rtgwg-backoff-algo-05

Abstract

   This document defines a standard algorithm to back-off link-state IGP
   SPF computations.

   Having one standard algorithm improves interoperability by reducing
   the probability and/or duration of transient forwarding loops during
   the IGP convergence when the IGP reacts to multiple temporally close
   IGP events.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

Decraene, et al.        Expires November 1, 2017                [Page 1]
Internet-Draft           SPF back-off algorithm               April 2017

   This Internet-Draft will expire on November 1, 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  High level goals  . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Definitions and parameters  . . . . . . . . . . . . . . . . .   4
   4.  Principles of SPF delay algorithm . . . . . . . . . . . . . .   5
   5.  Specification of the SPF delay state machine  . . . . . . . .   5
     5.1.  States  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     5.2.  States Transitions  . . . . . . . . . . . . . . . . . . .   6
     5.3.  FSM Events  . . . . . . . . . . . . . . . . . . . . . . .   7
   6.  Parameters  . . . . . . . . . . . . . . . . . . . . . . . . .   9
   7.  Partial Deployment  . . . . . . . . . . . . . . . . . . . . .   9
   8.  Impact on micro-loops . . . . . . . . . . . . . . . . . . . .  10
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   10. Security considerations . . . . . . . . . . . . . . . . . . .  10
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  10
     12.2.  Informative References . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   Link state IGPs, such as IS-IS [ISO10589-Second-Edition] and OSPF
   [RFC2328], perform distributed route computation on all routers in
   the area/level.  In order to have consistent routing tables across
   the network, such distributed computation requires that all routers
Show full document text