BGP Link-State Extensions for BGP-only Fabric
draft-ketant-idr-bgp-ls-bgp-only-fabric-05
Inter-Domain Routing K. Talaulikar
Internet-Draft C. Filsfils
Intended status: Standards Track K. Swamy
Expires: March 12, 2021 Cisco Systems
S. Zandi
G. Dawra
LinkedIn
M. Durrani
Equinix
September 8, 2020
BGP Link-State Extensions for BGP-only Fabric
draft-ketant-idr-bgp-ls-bgp-only-fabric-05
Abstract
BGP is used as the only routing protocol in some networks today. In
such networks, it is useful to get a detailed view of the nodes and
underlying links in the topology along with their attributes similar
to one available when using link state routing protocols. Such a
view of a BGP-only fabric enables use cases like traffic engineering
and forwarding of services along paths other than the BGP best path
selection.
This document defines extensions to the BGP Link-state address-family
(BGP-LS) and the procedures for advertisement of the topology in a
BGP-only network. It also describes a specific use-case for traffic
engineering based on Segment Routing.
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 12, 2021.
Talaulikar, et al. Expires March 12, 2021 [Page 1]
Internet-Draft BGP LS for BGP-only Fabric September 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. BGP Routing in the Fabric . . . . . . . . . . . . . . . . . . 3
3. Topology Collection Mechanism . . . . . . . . . . . . . . . . 4
3.1. Peering Models . . . . . . . . . . . . . . . . . . . . . 5
4. Advertising BGP-only Network Topology . . . . . . . . . . . . 6
4.1. Node Advertisements . . . . . . . . . . . . . . . . . . . 6
4.2. Link Advertisements . . . . . . . . . . . . . . . . . . . 7
4.3. Prefix Advertisements . . . . . . . . . . . . . . . . . . 10
4.4. TE Policy Advertisements . . . . . . . . . . . . . . . . 12
5. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1. Advertisement of Router's Node Attributes . . . . . . . . 13
5.2. Advertisement of Router's Local Links Attributes . . . . 15
5.3. Advertisement of Router's Prefix Attributes . . . . . . . 17
5.4. Advertisement of Router's TE Policy Attributes . . . . . 17
6. Usage of BGP Topology . . . . . . . . . . . . . . . . . . . . 18
6.1. Topology View for Monitoring . . . . . . . . . . . . . . 18
6.2. SR-TE in BGP Networks . . . . . . . . . . . . . . . . . . 18
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
8. Manageability Considerations . . . . . . . . . . . . . . . . 21
8.1. Operational Considerations . . . . . . . . . . . . . . . 21
8.1.1. Operations . . . . . . . . . . . . . . . . . . . . . 21
9. Security Considerations . . . . . . . . . . . . . . . . . . . 21
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
11.1. Normative References . . . . . . . . . . . . . . . . . . 21
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