IS-IS Routing for Spine-Leaf Topology
draft-ietf-lsr-isis-spine-leaf-ext-00

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Networking Working Group                                         N. Shen
Internet-Draft                                               L. Ginsberg
Intended status: Standards Track                           Cisco Systems
Expires: June 21, 2019                                  S. Thyamagundalu
                                                       December 18, 2018

                 IS-IS Routing for Spine-Leaf Topology
                 draft-ietf-lsr-isis-spine-leaf-ext-00

Abstract

   This document describes a mechanism for routers and switches in a
   Spine-Leaf type topology to have non-reciprocal Intermediate System
   to Intermediate System (IS-IS) routing relationships between the
   leafs and spines.  The leaf nodes do not need to have the topology
   information of other nodes and exact prefixes in the network.  This
   extension also has application in the Internet of Things (IoT).

Status of This Memo

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

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   This Internet-Draft will expire on June 21, 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
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   (http://trustee.ietf.org/license-info) in effect on the date of
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   include Simplified BSD License text as described in Section 4.e of

Shen, et al.              Expires June 21, 2019                 [Page 1]
Internet-Draft             IS-IS SL Extension              December 2018

   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  Motivations . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Spine-Leaf (SL) Extension . . . . . . . . . . . . . . . . . .   4
     3.1.  Topology Examples . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Applicability Statement . . . . . . . . . . . . . . . . .   5
     3.3.  Spine-Leaf TLV  . . . . . . . . . . . . . . . . . . . . .   6
       3.3.1.  Spine-Leaf Sub-TLVs . . . . . . . . . . . . . . . . .   7
         3.3.1.1.  Leaf-Set Sub-TLV  . . . . . . . . . . . . . . . .   7
         3.3.1.2.  Info-Req Sub-TLV  . . . . . . . . . . . . . . . .   8
       3.3.2.  Advertising IPv4/IPv6 Reachability  . . . . . . . . .   8
       3.3.3.  Advertising Connection to RF-Leaf Node  . . . . . . .   8
     3.4.  Mechanism . . . . . . . . . . . . . . . . . . . . . . . .   8
       3.4.1.  Pure CLOS Topology  . . . . . . . . . . . . . . . . .  10
     3.5.  Implementation and Operation  . . . . . . . . . . . . . .  11
       3.5.1.  CSNP PDU  . . . . . . . . . . . . . . . . . . . . . .  11
       3.5.2.  Overload Bit  . . . . . . . . . . . . . . . . . . . .  11
       3.5.3.  Spine Node Hostname . . . . . . . . . . . . . . . . .  11
       3.5.4.  IS-IS Reverse Metric  . . . . . . . . . . . . . . . .  11
       3.5.5.  Spine-Leaf Traffic Engineering  . . . . . . . . . . .  12
       3.5.6.  Other End-to-End Services . . . . . . . . . . . . . .  12
       3.5.7.  Address Family and Topology . . . . . . . . . . . . .  12
       3.5.8.  Migration . . . . . . . . . . . . . . . . . . . . . .  13
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  14
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  16

1.  Introduction

   The IS-IS routing protocol defined by [ISO10589] has been widely
   deployed in provider networks, data centers and enterprise campus
   environments.  In the data center and enterprise switching networks,
   a Spine-Leaf topology is commonly used.  This document describes a
   mechanism where IS-IS routing can be optimized for a Spine-Leaf