Segment Routing with MPLS data plane
draft-ietf-spring-segment-routing-mpls-19
The information below is for an old version of the document | |||
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Document | Type | Active Internet-Draft (spring WG) | |
Authors | Ahmed Bashandy , Clarence Filsfils , Stefano Previdi , Bruno Decraene , Stephane Litkowski , Rob Shakir | ||
Last updated | 2019-04-11 (latest revision 2019-03-28) | ||
Replaces | draft-filsfils-spring-segment-routing-mpls | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication (wg milestone: Oct 2018 - SR-MPLS sent to IESG... ) | |
Document shepherd | Shraddha Hegde | ||
Shepherd write-up | Show (last changed 2018-12-03) | ||
IESG | IESG state | IESG Evaluation::Revised I-D Needed | |
Consensus Boilerplate | Yes | ||
Telechat date |
Needs 4 more YES or NO OBJECTION positions to pass. |
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Responsible AD | Martin Vigoureux | ||
Send notices to | Shraddha Hegde <shraddha@juniper.net> | ||
IANA | IANA review state | IANA OK - No Actions Needed |
Network Working Group A. Bashandy, Ed. Internet Draft Arrcus Intended status: Standards Track C. Filsfils, Ed. Expires: September 2019 S. Previdi, Cisco Systems, Inc. B. Decraene S. Litkowski Orange R. Shakir Google March 28, 2019 Segment Routing with MPLS data plane draft-ietf-spring-segment-routing-mpls-19 Abstract Segment Routing (SR) leverages the source routing paradigm. A node steers a packet through a controlled set of instructions, called segments, by prepending the packet with an SR header. In the MPLS dataplane, the SR header is instantiated through a label stack. This document specifies the forwarding behavior to allow instantiating SR over the MPLS dataplane. 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 http://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 September 28, 2019. Filsfils, et al. Expires September 28, 2019 [Page 1] Internet-Draft Segment Routing with MPLS March 2019 Copyright Notice Copyright (c) 2019 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction...................................................3 1.1. Requirements Language.....................................4 2. MPLS Instantiation of Segment Routing..........................4 2.1. Multiple Forwarding Behaviors for the Same Prefix.........5 2.2. SID Representation in the MPLS Forwarding Plane...........5 2.3. Segment Routing Global Block and Local Block..............6 2.4. Mapping a SID Index to an MPLS label......................6 2.5. Incoming Label Collision..................................7 2.5.1. Tie-breaking Rules..................................10 2.5.2. Redistribution between Routing Protocol Instances...13 2.5.2.1. Illustration...................................13 2.5.2.2. Illustration 2.................................13 2.6. Effect of Incoming Label Collision on Outgoing Label Programming...................................................14 2.7. PUSH, CONTINUE, and NEXT.................................14 2.7.1. PUSH................................................14 2.7.2. CONTINUE............................................15 2.7.3. NEXT................................................15 2.7.3.1. Mirror SID.....................................15 2.8. MPLS Label Downloaded to FIB for Global and Local SIDs...15 2.9. Active Segment...........................................16 2.10. Forwarding behavior for Global SIDs.....................16 2.10.1. Forwarding for PUSH and CONTINUE of Global SIDs....16 2.10.2. Forwarding for NEXT Operation for Global SIDs......18 2.11. Forwarding Behavior for Local SIDs......................18 2.11.1. Forwarding for PUSH Operation on Local SIDs........18 2.11.2. Forwarding for CONTINUE Operation for Local SIDs...19 2.11.3. Outgoing label for NEXT Operation for Local SIDs...19 3. IANA Considerations...........................................19 Filsfils, et al. Expires September 28, 2019 [Page 2]Show full document text