Segment Routing MPLS Conflict Resolution
draft-ietf-spring-conflict-resolution-04

Document Type Active Internet-Draft (spring WG)
Last updated 2017-05-24
Replaces draft-ginsberg-spring-conflict-resolution
Stream IETF
Intended RFC status Proposed Standard
Formats plain text xml pdf html bibtex
Stream WG state WG Document
Document shepherd Martin Vigoureux
IESG IESG state I-D Exists
Consensus Boilerplate Yes
Telechat date
Responsible AD (None)
Send notices to (None)
Networking Working Group                                     L. Ginsberg
Internet-Draft                                                 P. Psenak
Intended status: Standards Track                              S. Previdi
Expires: November 25, 2017                                 Cisco Systems
                                                                M. Pilka
                                                            May 24, 2017

                Segment Routing MPLS Conflict Resolution
              draft-ietf-spring-conflict-resolution-04.txt

Abstract

   In support of Segment Routing (SR) for an MPLS data plane routing
   protocols advertise a variety of identifiers used to define the
   segments which direct forwarding of packets.  In cases where the
   information advertised by a given protocol instance is either
   internally inconsistent or conflicts with advertisements from another
   protocol instance a means of achieving consistent forwarding behavior
   in the network is required.  This document defines the policies used
   to resolve these occurrences.

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 RFC 2119 [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."

   This Internet-Draft will expire on November 25, 2017.

Ginsberg, et al.        Expires November 25, 2017               [Page 1]
Internet-Draft           sr-conflict-resolution                 May 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  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  SR Global Block Inconsistency . . . . . . . . . . . . . . . .   3
   3.  SR-MPLS Segment Identifier Conflicts  . . . . . . . . . . . .   5
     3.1.  SID Preference  . . . . . . . . . . . . . . . . . . . . .   6
     3.2.  Conflict Types  . . . . . . . . . . . . . . . . . . . . .   6
       3.2.1.  Prefix Conflict . . . . . . . . . . . . . . . . . . .   7
       3.2.2.  SID Conflict  . . . . . . . . . . . . . . . . . . . .   8
     3.3.  Preference rule for resolving conflicts . . . . . . . . .  10
     3.4.  Conflict Resolution Algorithm . . . . . . . . . . . . . .  11
     3.5.  Example Behavior - Single Topology/Address
           Family/Algorithm  . . . . . . . . . . . . . . . . . . . .  13
     3.6.  Example Behavior - Multiple Topologies  . . . . . . . . .  13
     3.7.  Guaranteeing Database Consistency . . . . . . . . . . . .  14
     3.8.  Minimizing the occurence of conflicts . . . . . . . . . .  14
   4.  Scope of SR-MPLS SID Conflicts  . . . . . . . . . . . . . . .  15
   5.  Conflict Resolution and non-forwarding nodes  . . . . . . . .  16
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  16
   7.  IANA Consideration  . . . . . . . . . . . . . . . . . . . . .  16
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  16
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  16
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  16
     9.2.  Informational References  . . . . . . . . . . . . . . . .  17
   Appendix A.  Alternative SID Conflict Resolution Policy
                Discussion . . . . . . . . . . . . . . . . . . . . .  17
     A.1.  Policy: Ignore conflicting entries  . . . . . . . . . . .  17
     A.2.  Policy: Preference Algorithm/Quarantine . . . . . . . . .  18
Show full document text