Multiple Algorithm support for IS-IS Prefixes
draft-chunduri-lsr-isis-prefix-multi-algo-01

Document Type Active Internet-Draft (individual)
Last updated 2018-10-22
Stream (None)
Intended RFC status (None)
Formats plain text pdf html bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
LSR Working Group                                            U. Chunduri
Internet-Draft                                                     Y. Qu
Intended status: Standards Track                              Huawei USA
Expires: April 25, 2019                                 October 22, 2018

             Multiple Algorithm support for IS-IS Prefixes
              draft-chunduri-lsr-isis-prefix-multi-algo-01

Abstract

   This document specifies an extension to Intermediate System to
   Intermediate System (IS-IS) protocol by adding an Algorithm support
   for prefixes advertised.  This allows multiple independent algorithm
   usage for computing the reachability of nodes and prefixes as opposed
   to only one algorithm.

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 [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 https://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 April 25, 2019.

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
   (https://trustee.ietf.org/license-info) in effect on the date of

Chunduri & Qu            Expires April 25, 2019                 [Page 1]
Internet-DraftMultiple Algorithm support for IS-IS Prefixes October 2018

   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
     1.1.  Acronyms  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  IS-IS Route Computation Algorithm sub-TLV in prefixes . . . .   3
   3.  Elements of Procedure . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Single Topology or Multi-Topology Mode  . . . . . . . . .   4
   4.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   5
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Reachability of various nodes or prefixes attached to these nodes is
   done through Shortest Path First (SPF) algorithm as defined in
   [ISO10589].  This is done today with in a single topology [RFC5305]
   [RFC5308] or in multi-topology (MT) routing [RFC5120] and with out
   any explicit advertisement of computation algorithm that is being
   used.

   IS-IS Segment Routing (SR) extensions
   [I-D.ietf-isis-segment-routing-extensions], extended the support for
   reachability computation for other algorithms other than SPF.  This
   is done by advertising the computation algorithms supported at node
   level and also by advertising the algorithm being supported by Prefix
   Segment Identifier (SID) sub-TLV advertised in reachability prefixes.

   While the above would give the flexibility to use different
   reachability computation algorithm than the SPF, it is restricted to
   one particular data plane as opposed to the prefix itself.  This
   document removes that restriction and advertises the algorithm to be
   used for reachability computation in the prefix itself, thus applying
   the same to any underlying data plane (E.g.  SR-MPLS, SRH, IPv6,
   IPv4).

   Section 2 details the details of the sub-TLV and Section 3 talks
   about how to use te same and restrictions around it.

Chunduri & Qu            Expires April 25, 2019                 [Page 2]
Internet-DraftMultiple Algorithm support for IS-IS Prefixes October 2018
Show full document text