Networking Working Group Ran. Chen Internet-Draft ZTE Corporation Intended status: Standards Track Samuel. Sidor Expires: August 26, 2021 Cisco Systems, Inc. Zhu. Chun ZTE Corporation Alex. Tokar Mike. Koldychev Cisco Systems, Inc. February 22, 2021 PCEP Extensions for sid verification for SR-MPLS draft-chen-pce-sr-mpls-sid-verification-01 Abstract This document updates [RFC8664] to clarify usage of "SID verification" bit signalled in Path Computation Element Protocol (PCEP), and this document proposes to define 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 August 26, 2021. Copyright Notice Copyright (c) 2021 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 Chen, et al. Expires August 26, 2021 [Page 1] Internet-Draft PCEP Ext for sid verification for SR-MPLS February 2021 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 2 3. SID verification flag(V-Flag) . . . . . . . . . . . . . . . . 3 3.1. Extended V-Flag in SR-ERO Subobject . . . . . . . . . . . 3 3.2. Extended V-Flag in SR-RRO Subobject . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 5.1. SR-ERO Subobject . . . . . . . . . . . . . . . . . . . . 4 6. 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 updates [RFC8664] to clarify usage of "SID verification" bit signalled in Path Computation Element Protocol (PCEP), and this document proposes to define a new flag for indicating the headend is explicitly requested to verify SID(s) by the PCE. 2. Conventions used in this document 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 RFC2119. Chen, et al. Expires August 26, 2021 [Page 2] Internet-Draft PCEP Ext for sid verification for SR-MPLS February 2021 3. SID verification flag(V-Flag) 3.1. Extended 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 for indicating the pcc is explicitly requested to verify SID(s) by the PCE. The format of the SR-ERO subobject as defined in [RFC8664] is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |L| Type=36 | Length | NT | Flags |V|F|S|C|M| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (optional) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // NAI (variable, optional) // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1 SR-ERO Subobject Format of extended V-Flag V: When the V-Flag is set then PCC MUST consider the "SID verification" as described in Section 5.1 in [I-D.ietf-spring-segment-routing-policy] . 3.2. Extended 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. 4. Security Considerations TBD. 5. IANA Considerations Chen, et al. Expires August 26, 2021 [Page 3] Internet-Draft PCEP Ext for sid verification for SR-MPLS February 2021 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. Bit Name Reference 7 SID verification(V) This document 6. Normative references [I-D.ietf-spring-segment-routing-policy] Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and P. Mattes, "Segment Routing Policy Architecture", draft- ietf-spring-segment-routing-policy-09 (work in progress), November 2020. [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 Ran Chen ZTE Corporation Email: chen.ran@zte.com.cn Samuel Sidor Cisco Systems, Inc. Email: ssidor@cisco.com Chun Zhu ZTE Corporation Email: zhu.chun1@zte.com.cn Alex Tokar Cisco Systems, Inc. Email: atokar@cisco.com Chen, et al. Expires August 26, 2021 [Page 4] Internet-Draft PCEP Ext for sid verification for SR-MPLS February 2021 Mike Koldychev Cisco Systems, Inc. Email: mkoldych@cisco.com Chen, et al. Expires August 26, 2021 [Page 5]