SR-TE Path Midpoint Protection
draft-hu-spring-segment-routing-proxy-forwarding-12

Document Type Active Internet-Draft (individual)
Authors Zhibo Hu , Huaimo Chen  , Junda Yao  , Chris Bowers  , Yongqing Zhu 
Last updated 2020-10-23
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Network Working Group                                              Z. Hu
Internet-Draft                                       Huawei Technologies
Intended status: Standards Track                                 H. Chen
Expires: April 26, 2021                                        Futurewei
                                                                  J. Yao
                                                     Huawei Technologies
                                                               C. Bowers
                                                        Juniper Networks
                                                                  Y. Zhu
                                                           China Telecom
                                                        October 23, 2020

                     SR-TE Path Midpoint Protection
          draft-hu-spring-segment-routing-proxy-forwarding-12

Abstract

   Segment Routing Traffic Engineering (SR-TE) supports explicit paths
   using segment lists containing adjacency-SIDs, node-SIDs and binding-
   SIDs.  The current SR FRR such as TI-LFA provides fast re-route
   protection for the failure of a node along a SR-TE path by the direct
   neighbor or say point of local repair (PLR) to the failure.  However,
   once the IGP converges, the SR FRR is no longer sufficient to forward
   traffic of the path around the failure, since the non-neighbors of
   the failure will no longer have a route to the failed node.  This
   document describes a mechanism for fast re-route protection against
   the failure of a SR-TE path after the IGP converges.  It provides
   fast re-route protection for an adjacency segment, a node segment and
   a binding segment of the path.

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.

   Internet-Drafts are working documents of the Internet Engineering
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Hu, et al.               Expires April 26, 2021                 [Page 1]
Internet-Draft          SR-TE Midpoint Protection           October 2020

   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on April 26, 2021.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Proxy Forwarding  . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Extensions to IGP for Proxy Forwarding  . . . . . . . . . . .   4
     3.1.  Extensions to OSPF  . . . . . . . . . . . . . . . . . . .   4
       3.1.1.  Advertising Proxy Forwarding  . . . . . . . . . . . .   4
       3.1.2.  Advertising Binding Segment . . . . . . . . . . . . .   7
     3.2.  Extensions to IS-IS . . . . . . . . . . . . . . . . . . .  10
       3.2.1.  Advertising Proxy Forwarding  . . . . . . . . . . . .  10
       3.2.2.  Advertising Binding Segment . . . . . . . . . . . . .  12
   4.  Building Proxy Forwarding Table . . . . . . . . . . . . . . .  13
     4.1.  Advertising Proxy Forwarding  . . . . . . . . . . . . . .  15
     4.2.  Building Proxy Forwarding Table . . . . . . . . . . . . .  15
   5.  Node Protection for Segment List  . . . . . . . . . . . . . .  15
     5.1.  Next Segment is an Adjacency Segment  . . . . . . . . . .  16
     5.2.  Next Segment is a Node Segment  . . . . . . . . . . . . .  16
     5.3.  Next Segment is a Binding Segment . . . . . . . . . . . .  17
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  18
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
     7.1.  OSPFv2  . . . . . . . . . . . . . . . . . . . . . . . . .  18
     7.2.  OSPFv3  . . . . . . . . . . . . . . . . . . . . . . . . .  19
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