RIFT: Routing in Fat Trees
draft-ietf-rift-rift-12

Document Type Active Internet-Draft (rift WG)
Last updated 2020-06-02 (latest revision 2020-05-26)
Replaces draft-przygienda-rift
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Stream WG state Submitted to IESG for Publication (wg milestones: Mar 2018 - Adopt a protocol spe..., Apr 2020 - Submit protocol spec... )
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RIFT Working Group                                    A. Przygienda, Ed.
Internet-Draft                                                   Juniper
Intended status: Standards Track                               A. Sharma
Expires: November 27, 2020                                       Comcast
                                                              P. Thubert
                                                                   Cisco
                                                          Bruno. Rijsman
                                                              Individual
                                                       Dmitry. Afanasiev
                                                                  Yandex
                                                            May 26, 2020

                       RIFT: Routing in Fat Trees
                        draft-ietf-rift-rift-12

Abstract

   This document defines a specialized, dynamic routing protocol for
   Clos and fat-tree network topologies optimized towards minimization
   of configuration and operational complexity.  The protocol

   o  deals with no configuration, fully automated construction of fat-
      tree topologies based on detection of links,

   o  minimizes the amount of routing state held at each level,

   o  automatically prunes and load balances topology flooding exchanges
      over a sufficient subset of links,

   o  supports automatic disaggregation of prefixes on link and node
      failures to prevent black-holing and suboptimal routing,

   o  allows traffic steering and re-routing policies,

   o  allows loop-free non-ECMP forwarding,

   o  automatically re-balances traffic towards the spines based on
      bandwidth available and finally

   o  provides mechanisms to synchronize a limited key-value data-store
      that can be used after protocol convergence to e.g.  bootstrap
      higher levels of functionality on nodes.

Przygienda, et al.      Expires November 27, 2020               [Page 1]
Internet-Draft                    RIFT                          May 2020

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on November 27, 2020.

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   Copyright (c) 2020 IETF Trust and the persons identified as the
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Table of Contents

   1.  Authors . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   6
     2.1.  Requirements Language . . . . . . . . . . . . . . . . . .   8
   3.  Reference Frame . . . . . . . . . . . . . . . . . . . . . . .   8
     3.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   8
     3.2.  Topology  . . . . . . . . . . . . . . . . . . . . . . . .  13
   4.  RIFT: Routing in Fat Trees  . . . . . . . . . . . . . . . . .  15
     4.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .  16
       4.1.1.  Properties  . . . . . . . . . . . . . . . . . . . . .  16
       4.1.2.  Generalized Topology View . . . . . . . . . . . . . .  17
         4.1.2.1.  Terminology . . . . . . . . . . . . . . . . . . .  17
         4.1.2.2.  Clos as Crossed Crossbars . . . . . . . . . . . .  18
       4.1.3.  Fallen Leaf Problem . . . . . . . . . . . . . . . . .  28
       4.1.4.  Discovering Fallen Leaves . . . . . . . . . . . . . .  30

Przygienda, et al.      Expires November 27, 2020               [Page 2]
Internet-Draft                    RIFT                          May 2020

       4.1.5.  Addressing the Fallen Leaves Problem  . . . . . . . .  31
     4.2.  Specification . . . . . . . . . . . . . . . . . . . . . .  32
       4.2.1.  Transport . . . . . . . . . . . . . . . . . . . . . .  33
       4.2.2.  Link (Neighbor) Discovery (LIE Exchange)  . . . . . .  33
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