Egress Protection for Segment Routing (SR) networks
draft-hegde-rtgwg-egress-protection-sr-networks-00

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Routing area                                                    S. Hegde
Internet-Draft                                                    W. Lin
Intended status: Standards Track                   Juniper Networks Inc.
Expires: September 9, 2020                                 March 8, 2020

          Egress Protection for Segment Routing (SR) networks
           draft-hegde-rtgwg-egress-protection-sr-networks-00

Abstract

   This document specifies a Fast Reroute(FRR) mechanism for protecting
   IP/MPLS services that use Segment Routing (SR) paths for transport
   against egress node and egress link failures.  The mechanism is based
   on egress protection framework described in
   [I-D.ietf-mpls-egress-protection-framework].  The egress protection
   mechanism can be further simplified in Segment Routing networks with
   anycast SIDs and anycast Locators.  This document addresses all kinds
   of networks that use Segment Routing transport such as SR-MPLS over
   IPv4, SR-MPLS over IPv6, SRv6 and SRm6.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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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   This Internet-Draft will expire on September 9, 2020.

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Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Egress Node Protection  . . . . . . . . . . . . . . . . . . .   3
     2.1.  SR-MPLS Networks  . . . . . . . . . . . . . . . . . . . .   4
     2.2.  SRm6 Networks . . . . . . . . . . . . . . . . . . . . . .   5
     2.3.  SRv6 Networks . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Egress Link Protection  . . . . . . . . . . . . . . . . . . .   6
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   7
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   Segment Routing Architecture as defined in [RFC8401] provides a
   simple and scalable MPLS control plane that removes state from
   transit nodes in the network.  SRm6 as defined in
   [I-D.bonica-spring-sr-mapped-six] and SRv6 as defined in
   [I-D.ietf-spring-srv6-network-programming] provide Segment Routing
   transport in pure IPv6 networks where MPLS data plane is not used.
   End-to-End resiliency is very important to satisfy Service Level
   Agreements (SLA) such as 50ms convergence.  The transport resiliency
   and fast rerouting are described
   in[I-D.ietf-rtgwg-segment-routing-ti-lfa] and
   [I-D.hegde-spring-node-protection-for-sr-te-paths].  Egress node and
   egress link failures are not covered by these protection mechanisms.
   Egress node and link failures need to address moving the services to
   other nodes where the customer services are multi-homed.  In
   traditional MPLS networks service labels (ex: L3VPN) are assigned

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   dynamically.  The protector nodes need to learn the service labels