A Simplified Scalable L3VPN Service Model with Segment Routing Underlay
draft-boutros-bess-l3vpn-services-over-sr-00
SPRING Workgroup S. Boutros, Ed.
Internet-Draft S. Sivabalan, Ed.
Intended status: Standards Track Ciena Corporation
Expires: May 6, 2021 J. Uttaro
AT&T
D. Voyer
Bell Canada
B. Wen
Comcast
L. Jalil
Verizon
November 2, 2020
A Simplified Scalable L3VPN Service Model with Segment Routing Underlay
draft-boutros-bess-l3vpn-services-over-sr-00
Abstract
This document proposes a new approach for realizing classical L3VPN
(vpnv4/vpnv6/6PE/6VPE) over Segment Routing (SR) networks. It
significantly improves scalability and convergence of the L3VPN
control plane. Furthermore, it naturally brings the benefits of All-
Active multi-homing support to the classical L3VPN.
Status of This Memo
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This Internet-Draft will expire on May 6, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
Boutros, et al. Expires May 6, 2021 [Page 1]
Internet-Draft L3VPN with Segment Routing November 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Control Plane Functionality . . . . . . . . . . . . . . . . . 5
4.1. Service discovery . . . . . . . . . . . . . . . . . . . . 5
5. Data Plane Behavior . . . . . . . . . . . . . . . . . . . . . 6
6. Service discovery . . . . . . . . . . . . . . . . . . . . . . 7
7. All-Active service Redundancy . . . . . . . . . . . . . . . . 7
8. Multi-pathing . . . . . . . . . . . . . . . . . . . . . . . . 7
9. Mass service withdrawal . . . . . . . . . . . . . . . . . . . 8
10. Benefits of L3VPN over SR . . . . . . . . . . . . . . . . . . 8
11. Security Considerations . . . . . . . . . . . . . . . . . . . 8
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
13. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 8
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
14.1. Normative References . . . . . . . . . . . . . . . . . . 8
14.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
Layer 3 VPN (L3VPN) enables a service provider to use an Internet
Protocol (IP) backbone to provide IP VPNs for customers. This
approach uses a peer model, in which the Customer Edge (CE) nodes
send their routes to the Service Provider Edge (PE) nodes. BGP is
used to exchange the routes of a particular VPN among the PE nodes
that are attached to that VPN. This is done in a way that ensures
that routes from different VPNs remain distinct and separate, even if
two VPNs have an overlapping address space. The PE nodes distribute
to the CE nodes in a particular VPN, the routes from other the CE
nodes in that VPN. The CE nodes do not peer with each other. Each
L3VPN route (v4/v6) advertisement is prepended with an 8-byte Route
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