PCE R. Chen Internet-Draft ZTE Corporation Intended status: Standards Track S. Sidor Expires: 28 January 2023 Cisco Systems, Inc. C. Zhu ZTE Corporation A. Tokar M. Koldychev Cisco Systems, Inc. 27 July 2022 PCEP Extensions for sid verification for SR-MPLS draft-chen-pce-sr-mpls-sid-verification-05 Abstract This document defines a new flag for indicating the headend is explicitly requested to verify SID(s) by the PCE. 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 https://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 28 January 2023. Copyright Notice Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved. Chen, et al. Expires 28 January 2023 [Page 1] Internet-Draft SID Verification for SR-MPLS July 2022 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2 3. SID verification flag(V-Flag) . . . . . . . . . . . . . . . . 3 3.1. V-Flag in SR-ERO Subobject . . . . . . . . . . . . . . . 3 3.2. V-Flag in SR-RRO Subobject . . . . . . . . . . . . . . . 3 3.3. SID verification Processing . . . . . . . . . . . . . . . 3 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 5.1. SR-ERO Subobject . . . . . . . . . . . . . . . . . . . . 3 5.2. LSP-ERROR-CODE TLV . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. Normative References . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction [I-D.ietf-spring-segment-routing-policy] describes the "SID verification" bit usage. SID verification is performed when the headend is explicitly requested to verify SID(s) by the controller via the signaling protocol used. Implementations MAY provide a local configuration option to enable verification on a global or per policy or per candidate path basis. [RFC8664] specifies extensions to the Path Computation Element Communication Protocol (PCEP) that allow a stateful PCE to compute and initiate Traffic-Engineering (TE) paths, as well as a Path Computation Client (PCC) to request a path subject to certain constraints and optimization criteria in SR networks. This document defines a new flag for indicating the headend is explicitly requested to verify SID(s) by the PCE. 2. 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]. Chen, et al. Expires 28 January 2023 [Page 2] Internet-Draft SID Verification for SR-MPLS July 2022 3. SID verification flag(V-Flag) 3.1. V-Flag in SR-ERO Subobject Section 4.3.1 in Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing [RFC8664] describes a new ERO subobject referred to as the "SR-ERO subobject" to carry a SID and/or NAI information. A new flag is proposed in this doucument in the SR- ERO Subobject [RFC8664] for indicating the pcc is explicitly requested to verify SID(s) by the PCE. V(1bit,TBD1): When the V-Flag is set then PCC MUST consider the "SID verification". 3.2. V-Flag in SR-RRO Subobject The format of the SR-RRO subobject is the same as that of the SR-ERO subobject, but without the L-Flag, per [RFC8664]. The V flag has no meaning in the SR-RRO and is ignored on receipt at the PCE. 3.3. SID verification Processing On receiving an SRv6-ERO with the V-flag is set, a PCC MUST verify SID(s) as described in Section 5.1 in [I-D.ietf-spring-segment-routing-policy]. If a PCC "Verification fails" for a SID, it MUST report this error by including the LSP-ERROR-CODE TLV with LSP error-value "SID Verification fails" in the LSP object in the PCRpt message to the PCE. 4. Acknowledgements We would like to thank Dhruv Dhody and John Scudder for their useful comments and suggestions. 5. IANA Considerations 5.1. SR-ERO Subobject This document defines a new bit value in the sub-registry "SR-ERO Flag Field" in the "Path Computation Element Protocol (PCEP) Numbers" registry. Chen, et al. Expires 28 January 2023 [Page 3] Internet-Draft SID Verification for SR-MPLS July 2022 Bit Name Reference --- ----------------------- -------------- TBD1 SID verification(V) This document Figure 1 5.2. LSP-ERROR-CODE TLV This document defines a new value in the sub-registry "LSP-ERROR-CODE TLV Error Code Field" in the "Path Computation Element Protocol (PCEP) Numbers" registry. Value Meaning Reference --- ----------------------- ----------- TBD2 SID Verification fails This document Figure 2 6. Security Considerations TBD. 7. Normative References [I-D.ietf-spring-segment-routing-policy] Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and P. Mattes, "Segment Routing Policy Architecture", Work in Progress, Internet-Draft, draft-ietf-spring-segment- routing-policy-22, 22 March 2022, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., and J. Hardwick, "Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing", RFC 8664, DOI 10.17487/RFC8664, December 2019, . Authors' Addresses Chen, et al. Expires 28 January 2023 [Page 4] Internet-Draft SID Verification for SR-MPLS July 2022 Ran Chen ZTE Corporation Nanjing China Email: chen.ran@zte.com.cn Samuel Sidor Cisco Systems, Inc. Email: ssidor@cisco.com Chun Zhu ZTE Corporation Nanjing China Email: zhu.chun1@zte.com.cn Alex Tokar Cisco Systems, Inc. Email: atokar@cisco.com Mike Koldychev Cisco Systems, Inc. Email: mkoldych@cisco.com Chen, et al. Expires 28 January 2023 [Page 5]