Dynamic Flooding on Dense Graphs
draft-ietf-lsr-dynamic-flooding-00
Internet Engineering Task Force T. Li, Ed.
Internet-Draft Arista Networks
Intended status: Standards Track P. Psenak, Ed.
Expires: August 29, 2019 L. Ginsberg
Cisco Systems, Inc.
T. Przygienda
Juniper Networks, Inc.
D. Cooper
CenturyLink
L. Jalil
Verizon
S. Dontula
ATT
February 25, 2019
Dynamic Flooding on Dense Graphs
draft-ietf-lsr-dynamic-flooding-00
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.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 29, 2019.
Li, et al. Expires August 29, 2019 [Page 1]
Internet-Draft Dynamic Flooding February 2019
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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
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