Dynamic Flooding on Dense Graphs
draft-ietf-lsr-dynamic-flooding-04
Internet Engineering Task Force T. Li, Ed.
Internet-Draft Arista Networks
Intended status: Standards Track P. Psenak, Ed.
Expires: May 29, 2020 L. Ginsberg
Cisco Systems, Inc.
H. Chen
Futurewei
T. Przygienda
Juniper Networks, Inc.
D. Cooper
CenturyLink
L. Jalil
Verizon
S. Dontula
ATT
November 26, 2019
Dynamic Flooding on Dense Graphs
draft-ietf-lsr-dynamic-flooding-04
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
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provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 29, 2020.
Li, et al. Expires May 29, 2020 [Page 1]
Internet-Draft Dynamic Flooding November 2019
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 5
3. Solution Requirements . . . . . . . . . . . . . . . . . . . . 5
4. Dynamic Flooding . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Applicability . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Leader election . . . . . . . . . . . . . . . . . . . . . 8
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 . . . . . . . . . . . . . . . . . . . 10
4.4.3. Optimization . . . . . . . . . . . . . . . . . . . . 11
4.5. Encoding the Flooding Topology . . . . . . . . . . . . . 11
4.6. Advertising the Local Edges Enabled for Flooding . . . . 11
5. Protocol Elements . . . . . . . . . . . . . . . . . . . . . . 12
5.1. IS-IS TLVs . . . . . . . . . . . . . . . . . . . . . . . 12
5.1.1. IS-IS Area Leader Sub-TLV . . . . . . . . . . . . . . 12
5.1.2. IS-IS Dynamic Flooding Sub-TLV . . . . . . . . . . . 13
5.1.3. IS-IS Area Node IDs TLV . . . . . . . . . . . . . . . 14
5.1.4. IS-IS Flooding Path TLV . . . . . . . . . . . . . . . 15
5.1.5. IS-IS Flooding Request TLV . . . . . . . . . . . . . 16
5.1.6. IS-IS LEEF Advertisement . . . . . . . . . . . . . . 18
5.2. OSPF LSAs and TLVs . . . . . . . . . . . . . . . . . . . 18
5.2.1. OSPF Area Leader Sub-TLV . . . . . . . . . . . . . . 18
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