Dynamic Flooding on Dense Graphs
draft-li-lsr-dynamic-flooding-02

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Internet Engineering Task Force                               T. Li, Ed.
Internet-Draft                                           Arista Networks
Intended status: Standards Track                          P. Psenak, Ed.
Expires: June 6, 2019                                        L. Ginsberg
                                                     Cisco Systems, Inc.
                                                           T. Przygienda
                                                  Juniper Networks, Inc.
                                                               D. Cooper
                                                             CenturyLink
                                                                L. Jalil
                                                                 Verizon
                                                              S. Dontula
                                                                     ATT
                                                        December 3, 2018

                    Dynamic Flooding on Dense Graphs
                    draft-li-lsr-dynamic-flooding-02

Abstract

   Routing with link state protocols in dense network topologies can
   result in sub-optimal convergence times due to the overhead
   associated with flooding.  This can be addressed by decreasing the
   flooding topology so that it is less dense.

   This document discusses the problem in some depth and an
   architectural solution.  Specific protocol changes for IS-IS, OSPFv2,
   and OSPFv3 are described in this document.

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
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   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on June 6, 2019.

Li, et al.                Expires June 6, 2019                  [Page 1]
Internet-Draft              Dynamic Flooding               December 2018

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   2.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Solution Requirements . . . . . . . . . . . . . . . . . . . .   5
   4.  Dynamic Flooding  . . . . . . . . . . . . . . . . . . . . . .   5
     4.1.  Applicability . . . . . . . . . . . . . . . . . . . . . .   7
     4.2.  Leader election . . . . . . . . . . . . . . . . . . . . .   7
     4.3.  Computing the Flooding Topology . . . . . . . . . . . . .   8
     4.4.  Topologies on Complete Bipartite Graphs . . . . . . . . .   9
       4.4.1.  A Minimal Flooding Topology . . . . . . . . . . . . .   9
       4.4.2.  Xia Topologies  . . . . . . . . . . . . . . . . . . .   9
       4.4.3.  Optimization  . . . . . . . . . . . . . . . . . . . .  10
     4.5.  Encoding the Flooding Topology  . . . . . . . . . . . . .  11
   5.  Protocol Elements . . . . . . . . . . . . . . . . . . . . . .  11
     5.1.  IS-IS TLVs  . . . . . . . . . . . . . . . . . . . . . . .  11
       5.1.1.  IS-IS Area Leader Sub-TLV . . . . . . . . . . . . . .  11
       5.1.2.  IS-IS Dynamic Flooding Sub-TLV  . . . . . . . . . . .  12
       5.1.3.  IS-IS Area System IDs TLV . . . . . . . . . . . . . .  13
       5.1.4.  IS-IS Flooding Path TLV . . . . . . . . . . . . . . .  14
       5.1.5.  IS-IS Flooding Request TLV  . . . . . . . . . . . . .  15
     5.2.  OSPF LSAs and TLVs  . . . . . . . . . . . . . . . . . . .  16
       5.2.1.  OSPF Area Leader Sub-TLV  . . . . . . . . . . . . . .  17
       5.2.2.  OSPF Dynamic Flooding Sub-TLV . . . . . . . . . . . .  17
       5.2.3.  OSPFv2 Dynamic Flooding Opaque LSA  . . . . . . . . .  18
       5.2.4.  OSPFv3 Dynamic Flooding LSA . . . . . . . . . . . . .  19
       5.2.5.  OSPF Area Router IDs TLV  . . . . . . . . . . . . . .  20