MPLS Segment Routing over IP
RFC 8663
Document | Type | RFC - Proposed Standard (December 2019; No errata) | |
---|---|---|---|
Authors | Xiaohu Xu , Stewart Bryant , Adrian Farrel , Syed Hassan , Wim Henderickx , Zhenbin Li | ||
Last updated | 2019-12-06 | ||
Replaces | draft-xu-mpls-sr-over-ip | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Loa Andersson | ||
Shepherd write-up | Show (last changed 2019-01-09) | ||
IESG | IESG state | RFC 8663 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Deborah Brungard | ||
Send notices to | Loa Andersson <loa@pi.nu> | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) X. Xu Request for Comments: 8663 Alibaba, Inc Category: Standards Track S. Bryant ISSN: 2070-1721 Futurewei Technologies A. Farrel Old Dog Consulting S. Hassan Cisco W. Henderickx Nokia Z. Li Huawei December 2019 MPLS Segment Routing over IP Abstract MPLS Segment Routing (SR-MPLS) is a method of source routing a packet through an MPLS data plane by imposing a stack of MPLS labels on the packet to specify the path together with any packet-specific instructions to be executed on it. SR-MPLS can be leveraged to realize a source-routing mechanism across MPLS, IPv4, and IPv6 data planes by using an MPLS label stack as a source-routing instruction set while making no changes to SR-MPLS specifications and interworking with SR-MPLS implementations. This document describes how SR-MPLS-capable routers and IP-only routers can seamlessly coexist and interoperate through the use of SR-MPLS label stacks and IP encapsulation/tunneling such as MPLS- over-UDP as defined in RFC 7510. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8663. 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 (https://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 1.1. Terminology 2. Use Cases 3. Procedures of SR-MPLS-over-IP 3.1. Forwarding Entry Construction 3.1.1. FIB Construction Example 3.2. Packet-Forwarding Procedures 3.2.1. Packet Forwarding with Penultimate Hop Popping 3.2.2. Packet Forwarding without Penultimate Hop Popping 3.2.3. Additional Forwarding Procedures 4. IANA Considerations 5. Security Considerations 6. References 6.1. Normative References 6.2. Informative References Acknowledgements Contributors Authors' Addresses 1. Introduction MPLS Segment Routing (SR-MPLS) [RFC8660] is a method of source routing a packet through an MPLS data plane. This is achieved by the sender imposing a stack of MPLS labels that partially or completely specify the path that the packet is to take and any instructions to be executed on the packet as it passes through the network. SR-MPLS uses an MPLS label stack to encode a sequence of source-routing instructions. This can be used to realize a source-routing mechanism that can operate across MPLS, IPv4, and IPv6 data planes. This approach makes no changes to SR-MPLS specifications and allows interworking with SR-MPLS implementations. More specifically, the source-routing instructions in a source-routed packet could be uniformly encoded as an MPLS label stack regardless of whether the underlay is IPv4, IPv6 (including Segment Routing for IPv6 (SRv6) [RFC8354]), or MPLS. This document describes how SR-MPLS-capable routers and IP-only routers can seamlessly coexist and interoperate through the use of SR-MPLS label stacks and IP encapsulation/tunneling such as MPLS- over-UDP [RFC7510]. Section 2 describes various use cases for tunneling SR-MPLS over IP. Section 3 describes a typical application scenario and how the packet forwarding happens.Show full document text