MPLS Working Group X. Min Internet-Draft P. Shaofu Intended status: Standards Track ZTE Corp. Expires: May 3, 2021 October 30, 2020 Label Switched Path (LSP) Ping/Traceroute for Segment Routing (SR) Path Segment Identifiers (SIDs) with MPLS Data Planes draft-xp-mpls-spring-lsp-ping-path-sid-00 Abstract Path Segment is a type of SR segment, which is used to identify an SR path. This document provides Target Forwarding Equivalence Class (FEC) stack TLV definitions for Path Segment Identifiers. 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 May 3, 2021. Copyright Notice Copyright (c) 2020 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. Min & Shaofu Expires May 3, 2021 [Page 1] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 3. Path Segment ID Sub-TLV . . . . . . . . . . . . . . . . . . . 3 3.1. SR Candidate Path's Path SID . . . . . . . . . . . . . . 3 3.2. SR Segment List's Path SID . . . . . . . . . . . . . . . 6 4. Path-SID FEC Validation . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1. Normative References . . . . . . . . . . . . . . . . . . 15 8.2. Informative References . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction Path Segment is a type of SR segment, which is used to identify an SR path. Path Segment in MPLS based segment routing network is defined in [I-D.ietf-spring-mpls-path-segment]. When Path Segment is used, it's inserted by the ingress node of the SR path, and then processed by the egress node of the SR path. The position of Path Segment Label within the MPLS label stack is immediately following the segment list of the SR path. Note that the Path Segment would not be popped up until it reaches the egress node. This document provides Target Forwarding Equivalence Class (FEC) stack TLV definitions for Path-SIDs. Procedures for LSP Ping and Traceroute as defined in [RFC8287] and [RFC8690] are applicable to Path-SIDs as well. 2. Conventions 2.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. Min & Shaofu Expires May 3, 2021 [Page 2] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 2.2. Terminology This document uses the terminology defined in [RFC8402] and [RFC8029], readers are expected to be familiar with those terms. 3. Path Segment ID Sub-TLV Analogous to what's defined in Section 5 of [RFC8287] and Section 4 of [I-D.ietf-mpls-sr-epe-oam], two new sub-TLVs are defined for the Target FEC Stack TLV (Type 1), the Reverse-Path Target FEC Stack TLV (Type 16), and the Reply Path TLV (Type 21). Sub-Type Sub-TLV Name -------- ----------------------------- TBD1 SR Candidate Path's Path SID TBD2 SR Segment List's Path SID As specified in Section 3 of [I-D.ietf-idr-sr-policy-path-segment], the Path Segment can be used to identify an SR path (specified by SID list) or an SR candidate path, so two different Target FEC sub-TLVs need to be defined for Path Segment ID. When a Path Segment is used to identify an SR path, then the Target FEC sub-TLV of SR Segment List's Path SID would be used to validate the control plane to forwarding plane synchronization for this Path-SID; When a Path Segment is used to identify an SR candidate path, then the Target FEC sub-TLV of SR Candidate Path's Path SID would be used to validate the control plane to forwarding plane synchronization for this Path-SID. 3.1. SR Candidate Path's Path SID The format of SR Candidate Path's Path SID sub-TLV is as specified below: Min & Shaofu Expires May 3, 2021 [Page 3] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = TBD1 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Headend (4/16 octets) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Color (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Endpoint (4/16 octets) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Protocol-Origin| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | | | Originator (20 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Discriminator (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: SR Candidate Path's Path SID sub-TLV Type This field is set to the value (TBD1) which indicates that it's a SR Candidate Path's Path SID sub-TLV. Length This field is set to the length of the sub-TLV's Value field in octets. If Headend and Endpoint fields are in IPv4 address format which is 4 octets long, it MUST be set to 40; If Headend and Endpoint fields are in IPv6 address format which is 16 octets long, it MUST be set to 64. Headend This field identifies the headend of an SR Policy, the same as defined in Section 2.1 of [I-D.ietf-spring-segment-routing-policy]. The headend is a 4-octet IPv4 address or a 16-octet IPv6 address. Color Min & Shaofu Expires May 3, 2021 [Page 4] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 This field associates the SR Policy with an intent, the same as defined in Section 2.1 of [I-D.ietf-spring-segment-routing-policy]. The color is a 4-octet numerical value. Endpoint This field identifies the endpoint of an SR Policy, the same as defined in Section 2.1 of [I-D.ietf-spring-segment-routing-policy]. The endpoint is a 4-octet IPv4 address or a 16-octet IPv6 address. Protocol-Origin This field identifies the component or protocol that originates or signals the candidate path for an SR Policy, the same as defined in Section 2.3 of [I-D.ietf-spring-segment-routing-policy]. The protocol-origin is a 1-octet value that follows the recommendation from Table 1 of Section 2.3 of [I-D.ietf-spring-segment-routing-policy], which specifies value 10 for "PCEP", value 20 for "BGP SR Policy" and value 30 for "Via Configuration". Originator This field identifies the node which provisioned or signaled the candidate path for an SR Policy, the same as defined in Section 2.4 of [I-D.ietf-spring-segment-routing-policy]. The originator is a 20-octet numerical value formed by the concatenation of the fields of the tuple , among which ASN is a 4-octet number and node address is a 16-octet value (an IPv6 address or an IPv4 address encoded in the lowest 4 octets). When Procotol-Origin is respectively "Via Configuration", or "PCEP", or "BGP SR Policy", the values of ASN and node address follow the specification in Section 2.4 of [I-D.ietf-spring-segment-routing-policy]. Discriminator This field uniquely identifies a candidate path within the context of an SR policy, the same as defined in Section 2.5 of [I-D.ietf-spring-segment-routing-policy]. The discriminator is a 4-octet value. When Protocol-Origin is respectively "Via Configuration", or "PCEP", or "BGP SR Policy", the value of discriminator follows the specification in Section 2.5 of [I-D.ietf-spring-segment-routing-policy]. Min & Shaofu Expires May 3, 2021 [Page 5] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 3.2. SR Segment List's Path SID The format of SR Segment List's Path SID sub-TLV is as specified below: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = TBD2 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Headend (4/16 octets) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Color (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Endpoint (4/16 octets) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Protocol-Origin| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | | | Originator (20 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Discriminator (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment-List-ID (4 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: SR Segment List's Path SID sub-TLV Type This field is set to the value (TBD2) which indicates that it's a SR Segment List's Path SID sub-TLV. Length This field is set to the length of the sub-TLV's Value field in octets. If Headend and Endpoint fields are in IPv4 address format which is 4 octets long, it MUST be set to 44; If Headend and Endpoint fields are in IPv6 address format which is 16 octets long, it MUST be set to 68. Min & Shaofu Expires May 3, 2021 [Page 6] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 Headend This field identifies the headend of an SR Policy, the same as defined in Section 2.1 of [I-D.ietf-spring-segment-routing-policy]. The headend is a 4-octet IPv4 address or a 16-octet IPv6 address. Color This field associates the SR Policy with an intent, the same as defined in Section 2.1 of [I-D.ietf-spring-segment-routing-policy]. The color is a 4-octet numerical value. Endpoint This field identifies the endpoint of an SR Policy, the same as defined in Section 2.1 of [I-D.ietf-spring-segment-routing-policy]. The endpoint is a 4-octet IPv4 address or a 16-octet IPv6 address. Protocol-Origin This field identifies the component or protocol that originates or signals the candidate path for an SR Policy, the same as defined in Section 2.3 of [I-D.ietf-spring-segment-routing-policy]. The protocol-origin is a 1-octet value that follows the recommendation from Table 1 of Section 2.3 of [I-D.ietf-spring-segment-routing-policy], which specifies value 10 for "PCEP", value 20 for "BGP SR Policy" and value 30 for "Via Configuration". Originator This field identifies the node which provisioned or signaled the candidate path for an SR Policy, the same as defined in Section 2.4 of [I-D.ietf-spring-segment-routing-policy]. The originator is a 20-octet numerical value formed by the concatenation of the fields of the tuple , among which ASN is a 4-octet number and node address is a 16-octet value (an IPv6 address or an IPv4 address encoded in the lowest 4 octets). When Procotol-Origin is respectively "Via Configuration", or "PCEP", or "BGP SR Policy", the values of ASN and node address follow the specification in Section 2.4 of [I-D.ietf-spring-segment-routing-policy]. Discriminator Min & Shaofu Expires May 3, 2021 [Page 7] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 This field uniquely identifies a candidate path within the context of an SR policy, the same as defined in Section 2.5 of [I-D.ietf-spring-segment-routing-policy]. The discriminator is a 4-octet value. When Protocol-Origin is respectively "Via Configuration", or "PCEP", or "BGP SR Policy", the value of discriminator follows the specification in Section 2.5 of [I-D.ietf-spring-segment-routing-policy]. Segment-List-ID This field identifies an SR path within the context of a candidate path of an SR Policy, the same as "List Identifier" defined in Section 2.2 of [I-D.lp-idr-sr-path-protection]. The segment-list- ID is a 4-octet identifier of the corresponding segment list. 4. Path-SID FEC Validation The MPLS LSP Ping/Traceroute procedures MAY be initiated by the headend of the Segment Routing path or a centralized topology-aware data plane monitoring system as described in [RFC8403]. For the Path-SID, the responder nodes that receive echo request and send echo reply MUST be the endpoint of the Segment Routing path. When an endpoint receives the LSP echo request packet with top FEC being the Path-SID, it SHOULD perform validity checks on the content of the Path-SID FEC sub-TLV. The basic length check should be performed on the received FEC. SR Candidate Path's Path SID ------------------ Length = 40 or 64 SR Segment List's Path SID ------------------ Length = 44 or 68 If a malformed FEC sub-TLV is received, then a return code of 1, "Malformed echo request received" as defined in [RFC8029] SHOULD be sent. The below section augments the section 7.4 of [RFC8287]. 4a. Segment Routing Path-SID Validation: If the Label-stack-depth is 0 and the Target FEC Stack sub-TLV at FEC-stack-depth is TBD1 (SR Candidate Path's Path SID sub-TLV), { Min & Shaofu Expires May 3, 2021 [Page 8] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 Set the Best-return-code to 10, "Mapping for this FEC is not the given label at stack-depth " if any below conditions fail: + Validate that the Path Segment ID is signaled or provisioned for the SR Candidate Path { - When the Protocol-Origin field in the received SR Candidate Path's Path SID sub-TLV is 10, "PCEP" is used as the signaling protocol. And then validate that the Path Segment ID matches with the tuples identifying the SR Candidate Path within PCEP { o Validate that the signaled headend defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the headend field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled color defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the color field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled end-point defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the endpoint field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled both originator ASN and originator address defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the originator field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled discriminator defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the discriminator field in the received SR Candidate Path's Path SID sub-TLV. } - When the Protocol-Origin field in the received SR Candidate Path's Path SID sub-TLV is 20, "BGP SR Policy" Min & Shaofu Expires May 3, 2021 [Page 9] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 is used as the signaling protocol. And then validate that the Path Segment ID matches with the tuples identifying the SR Candidate Path within BGP SR Policy { o Validate that the signaled headend defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the headend field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled policy color defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the color field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled endpoint defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the endpoint field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled both ASN and BGP Router-ID defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the originator field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the signaled distinguisher defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the discriminator field in the received SR Candidate Path's Path SID sub-TLV. } - When the Protocol-Origin field in the received SR Candidate Path's Path SID sub-TLV is 30, "Via Configuration" is used. And then validate that the Path Segment ID matches with the tuples identifying the SR Candidate Path within Configuration { o Validate that the provisioned headend defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the headend field in the received SR Candidate Path's Path SID sub-TLV. Min & Shaofu Expires May 3, 2021 [Page 10] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 o Validate that the provisioned color defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the color field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the provisioned endpoint defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the endpoint field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the provisioned originator defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the originator field in the received SR Candidate Path's Path SID sub-TLV. o Validate that the provisioned discriminator defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the discriminator field in the received SR Candidate Path's Path SID sub-TLV. } } If all the above validations have passed, set the return code to 3 "Replying router is an egress for the FEC at stack-depth ". Set FEC-Status to 1 and return. } Else, if the Label-stack-depth is 0 and the Target FEC Stack sub- TLV at FEC-stack-depth is TBD2 (SR Segment List's Path SID sub- TLV), { Set the Best-return-code to 10, "Mapping for this FEC is not the given label at stack-depth " if any below conditions fail: + Validate that the Path Segment ID is signaled or provisioned for the SR Segment List { - When the Protocol-Origin field in the received SR Segment List's Path SID sub-TLV is 10, "PCEP" is used as the signaling protocol. And then validate that the Path Segment ID matches with the tuples identifying the SR Segment List within PCEP { Min & Shaofu Expires May 3, 2021 [Page 11] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 o Validate that the signaled headend defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the headend field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled color defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the color field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled end-point defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the endpoint field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled both originator ASN and originator address defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the originator field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled discriminator defined in [I-D.ietf-pce-segment-routing-policy-cp] and [I-D.ietf-pce-sr-path-segment], for the Path SID, matches with the discriminator field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled Segment-List-ID by PCEP, for the Path SID, matches with the Segment-List-ID field in the received SR Segment List's Path SID sub- TLV. } - When the Protocol-Origin field in the received SR Segment List's Path SID sub-TLV is 20, "BGP SR Policy" is used as the signaling protocol. And then validate that the Path Segment ID matches with the tuples identifying the SR Segment List within BGP SR Policy { o Validate that the signaled headend defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path Min & Shaofu Expires May 3, 2021 [Page 12] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 SID, matches with the headend field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled policy color defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the color field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled endpoint defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the endpoint field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled both ASN and BGP Router-ID defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the originator field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled distinguisher defined in [I-D.ietf-idr-segment-routing-te-policy] and [I-D.ietf-idr-sr-policy-path-segment], for the Path SID, matches with the discriminator field in the received SR Segment List's Path SID sub-TLV. o Validate that the signaled List Identifier defined in [I-D.lp-idr-sr-path-protection], for the Path SID, matches with the Segment-List-ID field in the received SR Segment List's Path SID sub-TLV. } - When the Protocol-Origin field in the received SR Segment List's Path SID sub-TLV is 30, "Via Configuration" is used. And then validate that the Path Segment ID matches with the tuples identifying the SR Segment List within Configuration { o Validate that the provisioned headend defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the headend field in the received SR Segment List's Path SID sub-TLV. o Validate that the provisioned color defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, Min & Shaofu Expires May 3, 2021 [Page 13] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 matches with the color field in the received SR Segment List's Path SID sub-TLV. o Validate that the provisioned endpoint defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the endpoint field in the received SR Segment List's Path SID sub-TLV. o Validate that the provisioned originator defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the originator field in the received SR Segment List's Path SID sub-TLV. o Validate that the provisioned discriminator defined in [I-D.ietf-spring-sr-policy-yang], for the Path SID, matches with the discriminator field in the received SR Segment List's Path SID sub-TLV. o Validate that the provisioned Segment-List-ID through Yang Model, for the Path SID, matches with the Segment-List-ID field in the received SR Segment List's Path SID sub-TLV. } } If all the above validations have passed, set the return code to 3 "Replying router is an egress for the FEC at stack-depth ". Set FEC-Status to 1 and return. } 5. Security Considerations This document does not raise any additional security issues beyond those of the specifications referred to in the list of normative references. 6. IANA Considerations IANA is requested to assign two new sub-TLVs from the "sub-TLVs for TLV Types 1, 16, and 21" subregistry of the "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry [IANA]. Min & Shaofu Expires May 3, 2021 [Page 14] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 Sub-Type Sub-TLV Name Reference -------- ----------------------------- ------------ TBD1 SR Candidate Path's Path SID Section 3.1 TBD2 SR Segment List's Path SID Section 3.2 7. Acknowledgements The authors would like to acknowledge Zhao Detao for his thorough review and very helpful comments. 8. References 8.1. Normative References [I-D.ietf-spring-mpls-path-segment] Cheng, W., Li, H., Chen, M., Gandhi, R., and R. Zigler, "Path Segment in MPLS Based Segment Routing Network", draft-ietf-spring-mpls-path-segment-03 (work in progress), September 2020. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., Aldrin, S., and M. Chen, "Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures", RFC 8029, DOI 10.17487/RFC8029, March 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8287] Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya, N., Kini, S., and M. Chen, "Label Switched Path (LSP) Ping/Traceroute for Segment Routing (SR) IGP-Prefix and IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017, . [RFC8690] Nainar, N., Pignataro, C., Iqbal, F., and A. Vainshtein, "Clarification of Segment ID Sub-TLV Length for RFC 8287", RFC 8690, DOI 10.17487/RFC8690, December 2019, . Min & Shaofu Expires May 3, 2021 [Page 15] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 8.2. Informative References [I-D.ietf-idr-segment-routing-te-policy] Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., Rosen, E., Jain, D., and S. Lin, "Advertising Segment Routing Policies in BGP", draft-ietf-idr-segment-routing- te-policy-09 (work in progress), May 2020. [I-D.ietf-idr-sr-policy-path-segment] Li, C., Li, Z., Telecom, C., Cheng, W., and K. Talaulikar, "SR Policy Extensions for Path Segment and Bidirectional Path", draft-ietf-idr-sr-policy-path-segment-01 (work in progress), August 2020. [I-D.ietf-mpls-sr-epe-oam] Hegde, S., Arora, K., Srivastava, M., Ninan, S., and X. Xu, "Label Switched Path (LSP) Ping/Traceroute for Segment Routing (SR) Egress Peer Engineering Segment Identifiers (SIDs) with MPLS Data Planes", draft-ietf-mpls-sr-epe- oam-00 (work in progress), June 2020. [I-D.ietf-pce-segment-routing-policy-cp] Koldychev, M., Sivabalan, S., Barth, C., Peng, S., and H. Bidgoli, "PCEP extension to support Segment Routing Policy Candidate Paths", draft-ietf-pce-segment-routing-policy- cp-01 (work in progress), October 2020. [I-D.ietf-pce-sr-path-segment] Li, C., Chen, M., Cheng, W., Gandhi, R., and Q. Xiong, "Path Computation Element Communication Protocol (PCEP) Extension for Path Segment in Segment Routing (SR)", draft-ietf-pce-sr-path-segment-01 (work in progress), May 2020. [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-08 (work in progress), July 2020. [I-D.ietf-spring-sr-policy-yang] Raza, K., Sawaya, R., Shunwan, Z., Voyer, D., Durrani, M., Matsushima, S., and V. Beeram, "YANG Data Model for Segment Routing Policy", draft-ietf-spring-sr-policy- yang-00 (work in progress), September 2020. Min & Shaofu Expires May 3, 2021 [Page 16] Internet-Draft LSP Ping/Trace for SR Path SID October 2020 [I-D.lp-idr-sr-path-protection] Yao, L. and S. Peng, "BGP extensions of SR policy for path protection", draft-lp-idr-sr-path-protection-00 (work in progress), October 2020. [IANA] Internet Assigned Numbers Authority (IANA), "Multi- Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters", . [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, July 2018, . [RFC8403] Geib, R., Ed., Filsfils, C., Pignataro, C., Ed., and N. Kumar, "A Scalable and Topology-Aware MPLS Data-Plane Monitoring System", RFC 8403, DOI 10.17487/RFC8403, July 2018, . Authors' Addresses Xiao Min ZTE Corp. Nanjing China Email: xiao.min2@zte.com.cn Peng Shaofu ZTE Corp. Nanjing China Email: peng.shaofu@zte.com.cn Min & Shaofu Expires May 3, 2021 [Page 17]