IS-IS Routing with Reverse Metric
draft-ietf-isis-reverse-metric-08

Document Type Active Internet-Draft (isis WG)
Last updated 2018-01-09
Replaces draft-amante-isis-reverse-metric
Stream IETF
Intended RFC status Proposed Standard
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Stream WG state In WG Last Call
Document shepherd Christian Hopps
IESG IESG state I-D Exists
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Send notices to Christian Hopps <chopps@chopps.org>
Networking Working Group                                         N. Shen
Internet-Draft                                             Cisco Systems
Intended status: Standards Track                               S. Amante
Expires: July 12, 2018                                       Apple, Inc.
                                                          M. Abrahamsson
                                                        T-Systems Nordic
                                                         January 8, 2018

                   IS-IS Routing with Reverse Metric
                   draft-ietf-isis-reverse-metric-08

Abstract

   This document describes the mechanism to allow IS-IS routing to
   quickly and accurately shift traffic away from either a point-to-
   point or multi-access LAN interface by signaling to an adjacent IS-IS
   neighbor with the metric towards itself during network maintenance or
   other operational events.

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
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   This Internet-Draft will expire on July 12, 2018.

Copyright Notice

   Copyright (c) 2018 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

Shen, et al.              Expires July 12, 2018                 [Page 1]
Internet-Draft            IS-IS Reverse Metric              January 2018

   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
     1.1.  Node and Link Isolation . . . . . . . . . . . . . . . . .   2
     1.2.  Distributed Forwarding Planes . . . . . . . . . . . . . .   3
     1.3.  Spine-Leaf Applications . . . . . . . . . . . . . . . . .   3
     1.4.  LDP IGP Synchronization . . . . . . . . . . . . . . . . .   3
     1.5.  IS-IS Reverse Metric  . . . . . . . . . . . . . . . . . .   3
     1.6.  Specification of Requirements . . . . . . . . . . . . . .   4
   2.  IS-IS Reverse Metric TLV  . . . . . . . . . . . . . . . . . .   4
   3.  Elements of Procedure . . . . . . . . . . . . . . . . . . . .   6
     3.1.  Processing Changes to Default Metric  . . . . . . . . . .   6
     3.2.  Processing Changes to Default Metric for Multi-Topology
           IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . .   7
     3.3.  Multi-Access LAN Procedures . . . . . . . . . . . . . . .   7
     3.4.  Point-To-Point Link Procedures  . . . . . . . . . . . . .   8
     3.5.  LDP/IGP Synchronization on LANs . . . . . . . . . . . . .   8
     3.6.  Operational Guidelines  . . . . . . . . . . . . . . . . .   9
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  10
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  11
   Appendix A.  Node Isolation Challenges  . . . . . . . . . . . . .  11
   Appendix B.  Link Isolation Challenges  . . . . . . . . . . . . .  12
   Appendix C.  Contributors' Addresses  . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   The IS-IS [ISO10589] routing protocol has been widely used in
   Internet Service Provider IP/MPLS networks.  Operational experience
   with the protocol, combined with ever increasing requirements for
   lossless operations have demonstrated some operational issues.  This
   document describes the issues and a new mechanism for improving it.

1.1.  Node and Link Isolation

   IS-IS routing mechanism has the overload-bit, which can be used by
   operators to perform disruptive maintenance on the router.  But in
   many operational maintenance cases, it is not necessary to displace
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