rfc9884.original   rfc9884.txt 
MPLS Working Group X. Min Internet Engineering Task Force (IETF) X. Min
Internet-Draft S. Peng Request for Comments: 9884 S. Peng
Intended status: Standards Track ZTE Corp. Category: Standards Track ZTE Corp.
Expires: 8 December 2025 L. Gong ISSN: 2070-1721 L. Gong
China Mobile China Mobile
R. Gandhi R. Gandhi
Cisco Systems, Inc. Cisco Systems, Inc.
C. Pignataro C. Pignataro
Blue Fern Consulting Blue Fern Consulting
6 June 2025 October 2025
Label Switched Path Ping for Segment Routing Path Segment Identifier Label Switched Path Ping for Segment Routing Path Segment Identifier
with MPLS Data Plane with MPLS Data Plane
draft-ietf-mpls-spring-lsp-ping-path-sid-13
Abstract Abstract
Segment Routing (SR) leverages source routing to steer packets Segment Routing (SR) leverages source routing to steer packets
through an ordered list of instructions, called segments. SR can be through an ordered list of instructions called "segments". SR can be
instantiated over the MPLS data plane. Path Segment Identifiers instantiated over the MPLS data plane. Path Segment Identifiers
(PSIDs) are used to identify and correlate bidirectional or end-to- (PSIDs) are used to identify and correlate bidirectional or end-to-
end paths in Segment Routing networks. This document defines end paths in SR networks. This document defines procedures (i.e.,
procedures (i.e. six new Target forwarding Equivalence Class (FEC) six new Target Forwarding Equivalence Class (FEC) Stack sub-TLVs) for
Stack sub-TLVs) for the use of LSP Ping to support connectivity the use of LSP Ping to support connectivity verification and fault
verification and fault isolation for SR paths that include Path isolation for SR paths that include PSIDs. The mechanisms described
Segment Identifiers. The mechanisms described enable the validation enable the validation and tracing of SR paths with Path SIDs in MPLS
and tracing of SR paths with Path SIDs in MPLS networks, networks, complementing existing SR-MPLS Operations, Administration,
complementing existing SR-MPLS OAM capabilities. and Maintenance (OAM) capabilities.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
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 This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on 8 December 2025. 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/rfc9884.
Copyright Notice Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/ Provisions Relating to IETF Documents
license-info) in effect on the date of publication of this document. (https://trustee.ietf.org/license-info) in effect on the date of
Please review these documents carefully, as they describe your rights publication of this document. Please review these documents
and restrictions with respect to this document. Code Components carefully, as they describe your rights and restrictions with respect
extracted from this document must include Revised BSD License text as to this document. Code Components extracted from this document must
described in Section 4.e of the Trust Legal Provisions and are include Revised BSD License text as described in Section 4.e of the
provided without warranty as described in the Revised BSD License. Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2.1. Requirements Language
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Terminology
3. Path Segment ID Sub-TLVs . . . . . . . . . . . . . . . . . . 4 3. Path Segment ID Sub-TLVs
3.1. SR Policy Associated PSID - IPv4 Sub-TLV . . . . . . . . 5 3.1. SR Policy Associated PSID - IPv4 Sub-TLV
3.2. SR Candidate Path Associated PSID - IPv4 Sub-TLV . . . . 6 3.2. SR Candidate Path Associated PSID - IPv4 Sub-TLV
3.3. SR Segment List Associated PSID - IPv4 Sub-TLV . . . . . 8 3.3. SR Segment List Associated PSID - IPv4 Sub-TLV
3.4. SR Policy Associated PSID - IPv6 Sub-TLV . . . . . . . . 10 3.4. SR Policy Associated PSID - IPv6 Sub-TLV
3.5. SR Candidate Path Associated PSID - IPv6 Sub-TLV . . . . 11 3.5. SR Candidate Path Associated PSID - IPv6 Sub-TLV
3.6. SR Segment List Associated PSID - IPv6 Sub-TLV . . . . . 13 3.6. SR Segment List Associated PSID - IPv6 Sub-TLV
4. PSID FEC Validation . . . . . . . . . . . . . . . . . . . . . 15 4. PSID FEC Validation
4.1. PSID FEC Validation Rules . . . . . . . . . . . . . . . . 15 4.1. PSID FEC Validation Rules
5. Security Considerations . . . . . . . . . . . . . . . . . . . 19 5. Security Considerations
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 6. IANA Considerations
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20 7. References
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.1. Normative References
8.1. Normative References . . . . . . . . . . . . . . . . . . 20 7.2. Informative References
8.2. Informative References . . . . . . . . . . . . . . . . . 21 Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses
1. Introduction 1. Introduction
A Path Segment is a local segment [RFC9545] that uniquely identifies A Path Segment is a local segment [RFC9545] that uniquely identifies
an SR path on the egress node. A Path Segment Identifier (PSID) is a an SR path on the egress node. A Path Segment Identifier (PSID) is a
single label that is assigned from the Segment Routing Local Block single label that is assigned from the SR Local Block (SRLB)
(SRLB) [RFC8402] of the egress node of an SR path. [RFC8402] of the egress node of an SR path.
As specified in [RFC9545], PSID is a single label inserted by the As specified in [RFC9545], PSID is a single label inserted by the
ingress node of the SR path, and then processed by the egress node of ingress node of the SR path and then processed by the egress node of
the SR path. The PSID is placed within the MPLS label stack as a the SR path. The PSID is placed within the MPLS label stack as a
label immediately following the last label of the SR path. The label immediately following the last label of the SR path. The
egress node pops the PSID. egress node pops the PSID.
Procedure for LSP Ping [RFC8029] as defined in Section 7.4 of The procedure for LSP Ping [RFC8029] as defined in Section 7.4 of
[RFC8287] is also applicable to PSID, and this document appends [RFC8287] is also applicable to PSID; this document appends the
existing step 4a with a new step 4b specific to PSID. Concretely, existing step 4a with a new step 4b specific to PSID. Concretely,
LSP Ping can be used to check the correct operation of a PSID and LSP Ping can be used to check the correct operation of a PSID and
verify the PSID against the control plane. Checking correct verify the PSID against the control plane. Checking correct
operation means that an initiator can use LSP Ping to check whether a operation means that an initiator can use LSP Ping to check whether a
PSID reached the intended node and got processed by that node PSID reached the intended node and got processed by that node
correctly. Moreover, verifying a PSID against the control plane correctly. Moreover, verifying a PSID against the control plane
means that the initiator can use LSP Ping to verify the SR Path means that the initiator can use LSP Ping to verify the SR Path
context (segment-list, candidate path, or SR policy) associated with context (segment-list, candidate path, or SR policy) associated with
the PSID as signaled or provisioned at the egress node. To that end, the PSID as signaled or provisioned at the egress node. To that end,
this document specifies six new Target Forwarding Equivalence Class this document specifies six new Target Forwarding Equivalence Class
skipping to change at page 3, line 34 skipping to change at line 118
LSP Traceroute [RFC8287] is left out of this document because transit LSP Traceroute [RFC8287] is left out of this document because transit
nodes are not involved in PSID processing. nodes are not involved in PSID processing.
2. Conventions 2. Conventions
2.1. Requirements Language 2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
2.2. Terminology 2.2. Terminology
This document uses the terminology defined in [RFC3031], [RFC8402], This document uses the terminology defined in [RFC3031], [RFC8402],
[RFC8029], and [RFC9545], readers are expected to be familiar with [RFC8029], and [RFC9545]; readers are expected to be familiar with
those terms. the terms in those documents.
This document introduces the following additional term:
Segment-List-ID Segment-List-ID
The Segment-List-ID field is a 4-octet identifier that uniquely The Segment-List-ID field is a 4-octet identifier that uniquely
identifies a segment list within the context of the candidate path identifies a segment list within the context of the candidate path
of an SR Policy. Although not defined in [RFC9256], the Segment- of an SR Policy. Although not defined in [RFC9256], the Segment-
List-ID is the same identifier as the one that can be signalled List-ID is the same identifier as the one that can be signaled
through control plane procotols including BGP (Section 2.1 of through control plane protocols including Border Gateway Protocol
[I-D.ietf-idr-sr-policy-seglist-id], PCEP (Section 5.2 of (BGP) (Section 2.1 of [SR-SEGLIST-ID], Path Computation Element
[I-D.ietf-pce-multipath]), and BGP-LS (Section 5.7.4 of Communication Protocol (PCEP) (Section 4.2 of [PCE-MULTIPATH]),
[I-D.ietf-idr-bgp-ls-sr-policy]). and Border Gateway Protocol - Link State (BGP-LS) (Section 5.7.4
of [RFC9857]).
3. Path Segment ID Sub-TLVs 3. Path Segment ID Sub-TLVs
Analogous to what's defined in Section 5 of [RFC8287] and Section 4 Analogous to what's defined in Section 5 of [RFC8287] and Section 4
of [RFC9703], six new sub-TLVs are defined for the Target FEC Stack of [RFC9703], six new sub-TLVs are defined for the Target FEC Stack
TLV (Type 1), the Reverse-Path Target FEC Stack TLV (Type 16), and TLV (Type 1), the Reverse-Path Target FEC Stack TLV (Type 16), and
the Reply Path TLV (Type 21). Note that the structures of the six the Reply Path TLV (Type 21). Note that the structures of the six
new sub-TLVs follow the TLV's structure defined in Section 3 of new sub-TLVs follow the TLV's structure defined in Section 3 of
[RFC8029]. [RFC8029].
+==========+==========================================+ +==========+==========================================+
| Sub-Type | Sub-TLV Name | | Sub-Type | Sub-TLV Name |
+==========+==========================================+ +==========+==========================================+
| TBD1 | SR Policy Associated PSID - IPv4 | | 49 | SR Policy Associated PSID - IPv4 |
+----------+------------------------------------------+ +----------+------------------------------------------+
| TBD2 | SR Candidate Path Associated PSID - IPv4 | | 50 | SR Candidate Path Associated PSID - IPv4 |
+----------+------------------------------------------+ +----------+------------------------------------------+
| TBD3 | SR Segment List Associated PSID - IPv4 | | 51 | SR Segment List Associated PSID - IPv4 |
+----------+------------------------------------------+ +----------+------------------------------------------+
| TBD4 | SR Policy Associated PSID - IPv6 | | 52 | SR Policy Associated PSID - IPv6 |
+----------+------------------------------------------+ +----------+------------------------------------------+
| TBD5 | SR Candidate Path Associated PSID - IPv6 | | 53 | SR Candidate Path Associated PSID - IPv6 |
+----------+------------------------------------------+ +----------+------------------------------------------+
| TBD6 | SR Segment List Associated PSID - IPv6 | | 54 | SR Segment List Associated PSID - IPv6 |
+----------+------------------------------------------+ +----------+------------------------------------------+
Table 1: Sub-TLVs for PSID Checks Table 1: Sub-TLVs for PSID Checks
As specified in Section 2 of [RFC9545], a PSID is used to identify a As specified in Section 2 of [RFC9545], a PSID is used to identify
segment list, some or all segment lists in a Candidate path or an SR the following:
policy, so six different Target FEC Stack sub-TLVs need to be defined
* a single segment list, some segment lists, or all segment lists in
a candidate path of an SR policy,
* some segment lists across multiple candidate paths of an SR
policy, or
* all segment lists in all candidate paths of an SR policy.
Therefore, six different Target FEC Stack sub-TLVs need to be defined
for PSID. The ordered list of selection rules for the six Target FEC for PSID. The ordered list of selection rules for the six Target FEC
Stack sub-TLVs are defined as follows: Stack sub-TLVs are defined as follows:
* When a PSID is used to identify all segment lists in an SR Policy, * When a PSID is used to identify all segment lists in an SR Policy,
the Target FEC Stack sub-TLV of the type "SR Policy Associated the Target FEC Stack sub-TLV of the type "SR Policy Associated
PSID" (for IPv4 or IPv6) MUST be used for PSID checks. PSID" (for IPv4 or IPv6) MUST be used for PSID checks.
* When a PSID is used to identify all segment lists in an SR * When a PSID is used to identify all segment lists in an SR
Candidate Path, the Target FEC Stack sub-TLV of the type "SR Candidate Path, the Target FEC Stack sub-TLV of the type "SR
Candidate Path Associated PSID" (for IPv4 or IPv6) MUST be used Candidate Path Associated PSID" (for IPv4 or IPv6) MUST be used
skipping to change at page 5, line 24 skipping to change at line 206
* When a PSID is used to identify some segment lists in a Candidate * When a PSID is used to identify some segment lists in a Candidate
path or an SR policy, the Target FEC Stack sub-TLV of the type "SR path or an SR policy, the Target FEC Stack sub-TLV of the type "SR
Segment List Associated PSID" (for IPv4 or IPv6) MUST be used for Segment List Associated PSID" (for IPv4 or IPv6) MUST be used for
PSID checks. In this case, multiple LSP Ping messages MUST be PSID checks. In this case, multiple LSP Ping messages MUST be
sent, and one Target FEC Stack sub-TLV of the type "SR Segment sent, and one Target FEC Stack sub-TLV of the type "SR Segment
List Associated PSID" (for IPv4 or IPv6) MUST be carried in each List Associated PSID" (for IPv4 or IPv6) MUST be carried in each
LSP Ping message. LSP Ping message.
These six new Target FEC Stack sub-TLVs are not expected to be These six new Target FEC Stack sub-TLVs are not expected to be
present in the same message. If more than one of these sub-TLVs are present in the same message. If more than one of these sub-TLVs are
present in a message, only the first sub-TLV will be processed per present in a message, only the first sub-TLV will be processed, per
the validation rules in Section 4. the validation rules in Section 4.
3.1. SR Policy Associated PSID - IPv4 Sub-TLV 3.1. SR Policy Associated PSID - IPv4 Sub-TLV
The SR Policy Associated PSID - IPv4 sub-TLV is defined as follows: The SR Policy Associated PSID - IPv4 sub-TLV is defined as follows:
0 1 2 3 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 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 | | Type = 49 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Headend (4 octets) | | Headend (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Color (4 octets) | | Color (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Endpoint (4 octets) | | Endpoint (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: SR Policy Associated PSID - IPv4 sub-TLV Format Figure 1: SR Policy Associated PSID - IPv4 Sub-TLV Format
Type (length: 2 octets) Type (length: 2 octets)
The Type field identifies the sub-TLV as an SR Policy Associated The Type field identifies the sub-TLV as an SR Policy Associated
PSID - IPv4 Sub-TLV. The value is set to (TBD1) and is to be PSID - IPv4 sub-TLV. The value is set to 49.
assigned by IANA.
Length (length: 2 octets) Length (length: 2 octets)
The Length field indicates the length of the sub-TLV in octets, The Length field indicates the length of the sub-TLV in octets,
excluding the first 4 octets (Type and Length fields). The value excluding the first 4 octets (Type and Length fields). The value
MUST be set to 12. MUST be set to 12.
Headend (length: 4 octets) Headend (length: 4 octets)
The Headend field encodes the headend IPv4 address of the SR The Headend field encodes the headend IPv4 address of the SR
Policy. This field is defined in Section 2.1 of [RFC9256]. Policy. This field is defined in Section 2.1 of [RFC9256].
Color (length: 4 octets) Color (length: 4 octets)
The Color field identifies the color (i.e., policy identifier) of The Color field identifies the color (i.e., policy identifier) of
the SR Policy and is encoded as defined in Section 2.1 of the SR Policy and is encoded as defined in Section 2.1 of
[RFC9256]. [RFC9256].
Endpoint (length: 4 octets) Endpoint (length: 4 octets)
The Endpoint field encodes the endpoint IPv4 address of the SR The Endpoint field encodes the endpoint IPv4 address of the SR
Policy. This field is defined in Section 2.1 of [RFC9256]. Policy. This field is defined in Section 2.1 of [RFC9256].
3.2. SR Candidate Path Associated PSID - IPv4 Sub-TLV 3.2. SR Candidate Path Associated PSID - IPv4 Sub-TLV
The SR Candidate Path Associated PSID - IPv4 sub-TLV is defined as The SR Candidate Path Associated PSID - IPv4 sub-TLV is defined as
follows: follows:
0 1 2 3 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 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 | | Type = 50 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Headend (4 octets) | | Headend (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Color (4 octets) | | Color (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Endpoint (4 octets) | | Endpoint (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Protocol-Origin| Reserved | |Protocol-Origin| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
| Originator (20 octets) | | Originator (20 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Discriminator (4 octets) | | Discriminator (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: SR Candidate Path Associated PSID - IPv4 sub-TLV Format
Type (length: 2 octets) Figure 2: SR Candidate Path Associated PSID - IPv4 Sub-TLV Format
Type (length: 2 octets)
The Type field identifies the sub-TLV as an SR Candidate Path The Type field identifies the sub-TLV as an SR Candidate Path
Associated PSID - IPv4 sub-TLV. The value is set to (TBD2) and is Associated PSID - IPv4 sub-TLV. The value is set to 50.
to be assigned by IANA.
Length (length: 2 octets) Length (length: 2 octets)
The Length field indicates the length of the sub-TLV in octets, The Length field indicates the length of the sub-TLV in octets,
excluding the first 4 octets (Type and Length fields). The value excluding the first 4 octets (Type and Length fields). The value
MUST be set to 40. MUST be set to 40.
Headend (length: 4 octets) Headend (length: 4 octets)
The Headend field encodes the headend IPv4 address of the SR The Headend field encodes the headend IPv4 address of the SR
Candidate Path. This field is defined in Section 2.1 of Candidate Path. This field is defined in Section 2.1 of
[RFC9256]. [RFC9256].
Color (length: 4 octets) Color (length: 4 octets)
The Color field identifies the policy color and is defined in The Color field identifies the policy color and is defined in
Section 2.1 of [RFC9256]. Section 2.1 of [RFC9256].
Endpoint (length: 4 octets) Endpoint (length: 4 octets)
The Endpoint field encodes the endpoint IPv4 address of the SR The Endpoint field encodes the endpoint IPv4 address of the SR
Candidate Path. This field is defined in Section 2.1 of Candidate Path. This field is defined in Section 2.1 of
[RFC9256]. [RFC9256].
Protocol-Origin (length: 1 octet) Protocol-Origin (length: 1 octet)
The Protocol-Origin field indicates the protocol that originated The Protocol-Origin field indicates the protocol that originated
the SR Candidate Path. It is defined in Section 2.3 of [RFC9256] the SR Candidate Path. It is defined in Section 2.3 of [RFC9256]
and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an
unsupported value is used, validation at the responder MUST fail. unsupported value is used, validation at the responder MUST fail.
Reserved (length: 3 octets) Reserved (length: 3 octets)
The Reserved field is reserved for future use. It MUST be set to The Reserved field is reserved for future use. It MUST be set to
zero when sent and MUST be ignored upon receipt. zero when sent and MUST be ignored upon receipt.
Originator (length: 20 octets) Originator (length: 20 octets)
The Originator field identifies the originator of the SR Candidate The Originator field identifies the originator of the SR Candidate
Path and is encoded as defined in Section 2.4 of [RFC9256]. Path and is encoded as defined in Section 2.4 of [RFC9256].
Discriminator (length: 4 octets) Discriminator (length: 4 octets)
The Discriminator field uniquely identifies the SR Candidate Path The Discriminator field uniquely identifies the SR Candidate Path
within the context of the Headend, Color, and Endpoint. This within the context of the Headend, Color, and Endpoint fields.
field is defined in Section 2.5 of [RFC9256]. This field is defined in Section 2.5 of [RFC9256].
3.3. SR Segment List Associated PSID - IPv4 Sub-TLV 3.3. SR Segment List Associated PSID - IPv4 Sub-TLV
The SR Segment List Associated PSID - IPv4 sub-TLV is used to The SR Segment List Associated PSID - IPv4 sub-TLV is used to
identify a specific segment list within the context of a candidate identify a specific segment list within the context of a candidate
path of an SR Policy. The format of this sub-TLV is shown in path of an SR Policy. The format of this sub-TLV is shown in
Figure 3. Figure 3.
0 1 2 3 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 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 = TBD3 | Length | | Type = 51 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Headend (4 octets) | | Headend (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Color (4 octets) | | Color (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Endpoint (4 octets) | | Endpoint (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Protocol-Origin| Reserved | |Protocol-Origin| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
| Originator (20 octets) | | Originator (20 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Discriminator (4 octets) | | Discriminator (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment-List-ID (4 octets) | | Segment-List-ID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: SR Segment List Associated PSID - IPv4 sub-TLV Format Figure 3: SR Segment List Associated PSID - IPv4 Sub-TLV Format
Type (length: 2 octets) Type (length: 2 octets)
The Type field identifies the sub-TLV as an SR Segment List The Type field identifies the sub-TLV as an SR Segment List
Associated PSID - IPv4 sub-TLV. The value is set to (TBD3) and is Associated PSID - IPv4 sub-TLV. The value is set to 51.
to be assigned by IANA.
Length (length: 2 octets) Length (length: 2 octets)
The Length field indicates the length of the sub-TLV in octets, The Length field indicates the length of the sub-TLV in octets,
excluding the first 4 octets (Type and Length fields). The value excluding the first 4 octets (Type and Length fields). The value
MUST be set to 44. MUST be set to 44.
Headend (length: 4 octets) Headend (length: 4 octets)
The Headend field encodes the headend IPv4 address of the SR The Headend field encodes the headend IPv4 address of the SR
Policy. This field is defined in Section 2.1 of [RFC9256]. Policy. This field is defined in Section 2.1 of [RFC9256].
Color (length: 4 octets) Color (length: 4 octets)
The Color field identifies the color of the SR Policy and is The Color field identifies the color of the SR Policy and is
encoded as specified in Section 2.1 of [RFC9256]. encoded as specified in Section 2.1 of [RFC9256].
Endpoint (length: 4 octets) Endpoint (length: 4 octets)
The Endpoint field specifies the endpoint IPv4 address of the SR The Endpoint field specifies the endpoint IPv4 address of the SR
Policy, as defined in Section 2.1 of [RFC9256]. Policy, as defined in Section 2.1 of [RFC9256].
Protocol-Origin (length: 1 octet) Protocol-Origin (length: 1 octet)
The Protocol-Origin field indicates the protocol that originated The Protocol-Origin field indicates the protocol that originated
the SR Candidate Path. It is defined in Section 2.3 of [RFC9256] the SR Candidate Path. It is defined in Section 2.3 of [RFC9256]
and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an
unsupported value is used, validation at the responder MUST fail. unsupported value is used, validation at the responder MUST fail.
Reserved (length: 3 octets) Reserved (length: 3 octets)
The Reserved field is reserved for future use. It MUST be set to The Reserved field is reserved for future use. It MUST be set to
zero when transmitted and MUST be ignored upon receipt. zero when transmitted and MUST be ignored upon receipt.
Originator (length: 20 octets) Originator (length: 20 octets)
The Originator field identifies the originator of the SR Candidate The Originator field identifies the originator of the SR Candidate
Path and is defined in Section 2.4 of [RFC9256]. Path and is defined in Section 2.4 of [RFC9256].
Discriminator (length: 4 octets) Discriminator (length: 4 octets)
The Discriminator field uniquely identifies the SR Candidate Path The Discriminator field uniquely identifies the SR Candidate Path
within the context of the Headend, Color, and Endpoint. This within the context of the Headend, Color, and Endpoint fields.
field is defined in Section 2.5 of [RFC9256]. This field is defined in Section 2.5 of [RFC9256].
Segment-List-ID (length: 4 octets) Segment-List-ID (length: 4 octets)
The Segment-List-ID field is a 4-octet identifier that uniquely The Segment-List-ID field is a 4-octet identifier that uniquely
identifies a segment list within the context of the candidate path identifies a segment list within the context of the candidate path
of an SR Policy. This field is defined in terminology of of an SR Policy. This field is defined in Section 2.2.
Section 2.2.
3.4. SR Policy Associated PSID - IPv6 Sub-TLV 3.4. SR Policy Associated PSID - IPv6 Sub-TLV
The SR Policy Associated PSID - IPv6 sub-TLV is defined as follows: The SR Policy Associated PSID - IPv6 sub-TLV is defined as follows:
0 1 2 3 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 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 = TBD4 | Length | | Type = 52 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Headend (16 octets) | | Headend (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Color (4 octets) | | Color (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Endpoint (16 octets) | | Endpoint (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: SR Policy Associated PSID - IPv6 sub-TLV Format Figure 4: SR Policy Associated PSID - IPv6 Sub-TLV Format
Type (length: 2 octets) Type (length: 2 octets)
The Type field identifies the sub-TLV as an SR Policy Associated The Type field identifies the sub-TLV as an SR Policy Associated
PSID - IPv6 Sub-TLV. The value is set to (TBD4) and is to be PSID - IPv6 sub-TLV. The value is set to 52.
assigned by IANA.
Length (length: 2 octets) Length (length: 2 octets)
The Length field indicates the length of the sub-TLV in octets, The Length field indicates the length of the sub-TLV in octets,
excluding the first 4 octets (Type and Length fields). The value excluding the first 4 octets (Type and Length fields). The value
MUST be set to 36. MUST be set to 36.
Headend (length: 16 octets) Headend (length: 16 octets)
The Headend field encodes the headend IPv6 address of the SR The Headend field encodes the headend IPv6 address of the SR
Policy. This field is defined in Section 2.1 of [RFC9256]. Policy. This field is defined in Section 2.1 of [RFC9256].
Color (length: 4 octets) Color (length: 4 octets)
The Color field identifies the color (i.e., policy identifier) of The Color field identifies the color (i.e., policy identifier) of
the SR Policy and is encoded as defined in Section 2.1 of the SR Policy and is encoded as defined in Section 2.1 of
[RFC9256]. [RFC9256].
Endpoint (length: 16 octets) Endpoint (length: 16 octets)
The Endpoint field encodes the endpoint IPv6 address of the SR The Endpoint field encodes the endpoint IPv6 address of the SR
Policy. This field is defined in Section 2.1 of [RFC9256]. Policy. This field is defined in Section 2.1 of [RFC9256].
3.5. SR Candidate Path Associated PSID - IPv6 Sub-TLV 3.5. SR Candidate Path Associated PSID - IPv6 Sub-TLV
The SR Candidate Path Associated PSID - IPv6 sub-TLV is defined as The SR Candidate Path Associated PSID - IPv6 sub-TLV is defined as
follows: follows:
0 1 2 3 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 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 = TBD5 | Length | | Type = 53 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Headend (16 octets) | | Headend (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Color (4 octets) | | Color (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Endpoint (16 octets) | | Endpoint (16 octets) |
skipping to change at page 11, line 43 skipping to change at line 477
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
| Originator (20 octets) | | Originator (20 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Discriminator (4 octets) | | Discriminator (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: SR Candidate Path Associated PSID - IPv6 sub-TLV Format Figure 5: SR Candidate Path Associated PSID - IPv6 Sub-TLV Format
Type (length: 2 octets) Type (length: 2 octets)
The Type field identifies the sub-TLV as an SR Candidate Path The Type field identifies the sub-TLV as an SR Candidate Path
Associated PSID - IPv6 sub-TLV. The value is set to (TBD5) and is Associated PSID - IPv6 sub-TLV. The value is set to 53.
to be assigned by IANA.
Length (length: 2 octets) Length (length: 2 octets)
The Length field indicates the length of the sub-TLV in octets, The Length field indicates the length of the sub-TLV in octets,
excluding the first 4 octets (Type and Length fields). The value excluding the first 4 octets (Type and Length fields). The value
MUST be set to 64. MUST be set to 64.
Headend (length: 16 octets) Headend (length: 16 octets)
The Headend field encodes the headend IPv6 address of the SR The Headend field encodes the headend IPv6 address of the SR
Candidate Path. This field is defined in Section 2.1 of Candidate Path. This field is defined in Section 2.1 of
[RFC9256]. [RFC9256].
Color (length: 4 octets) Color (length: 4 octets)
The Color field identifies the policy color and is defined in The Color field identifies the policy color and is defined in
Section 2.1 of [RFC9256]. Section 2.1 of [RFC9256].
Endpoint (length: 16 octets) Endpoint (length: 16 octets)
The Endpoint field encodes the endpoint IPv6 address of the SR The Endpoint field encodes the endpoint IPv6 address of the SR
Candidate Path. This field is defined in Section 2.1 of Candidate Path. This field is defined in Section 2.1 of
[RFC9256]. [RFC9256].
Protocol-Origin (length: 1 octet) Protocol-Origin (length: 1 octet)
The Protocol-Origin field indicates the protocol that originated The Protocol-Origin field indicates the protocol that originated
the SR Candidate Path. It is defined in Section 2.3 of [RFC9256] the SR Candidate Path. It is defined in Section 2.3 of [RFC9256]
and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an
unsupported value is used, validation at the responder MUST fail. unsupported value is used, validation at the responder MUST fail.
Reserved (length: 3 octets) Reserved (length: 3 octets)
The Reserved field is reserved for future use. It MUST be set to The Reserved field is reserved for future use. It MUST be set to
zero when sent and MUST be ignored upon receipt. zero when sent and MUST be ignored upon receipt.
Originator (length: 20 octets) Originator (length: 20 octets)
The Originator field identifies the originator of the SR Candidate The Originator field identifies the originator of the SR Candidate
Path and is encoded as defined in Section 2.4 of [RFC9256]. Path and is encoded as defined in Section 2.4 of [RFC9256].
Discriminator (length: 4 octets) Discriminator (length: 4 octets)
The Discriminator field uniquely identifies the SR Candidate Path The Discriminator field uniquely identifies the SR Candidate Path
within the context of the Headend, Color, and Endpoint. This within the context of the Headend, Color, and Endpoint fields.
field is defined in Section 2.5 of [RFC9256]. This field is defined in Section 2.5 of [RFC9256].
3.6. SR Segment List Associated PSID - IPv6 Sub-TLV 3.6. SR Segment List Associated PSID - IPv6 Sub-TLV
The SR Segment List Associated PSID - IPv6 sub-TLV is used to The SR Segment List Associated PSID - IPv6 sub-TLV is used to
identify a specific segment list within the context of a candidate identify a specific segment list within the context of a candidate
path of an SR Policy. The format of this sub-TLV is shown in path of an SR Policy. The format of this sub-TLV is shown in
Figure 6. Figure 6.
0 1 2 3 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 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 = TBD6 | Length | | Type = 54 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Headend (16 octets) | | Headend (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Color (4 octets) | | Color (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Endpoint (16 octets) | | Endpoint (16 octets) |
skipping to change at page 13, line 42 skipping to change at line 558
| | | |
| Originator (20 octets) | | Originator (20 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Discriminator (4 octets) | | Discriminator (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment-List-ID (4 octets) | | Segment-List-ID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: SR Segment List Associated PSID - IPv6 sub-TLV Format Figure 6: SR Segment List Associated PSID - IPv6 Sub-TLV Format
Type (length: 2 octets) Type (length: 2 octets)
The Type field identifies the sub-TLV as an SR Segment List The Type field identifies the sub-TLV as an SR Segment List
Associated PSID - IPv6 sub-TLV. The value is set to (TBD6) and is Associated PSID - IPv6 sub-TLV. The value is set to 54.
to be assigned by IANA.
Length (length: 2 octets) Length (length: 2 octets)
The Length field indicates the length of the sub-TLV in octets, The Length field indicates the length of the sub-TLV in octets,
excluding the first 4 octets (Type and Length fields). The value excluding the first 4 octets (Type and Length fields). The value
MUST be set to 68. MUST be set to 68.
Headend (length: 16 octets) Headend (length: 16 octets)
The Headend field encodes the headend IPv6 address of the SR The Headend field encodes the headend IPv6 address of the SR
Policy. This field is defined in Section 2.1 of [RFC9256]. Policy. This field is defined in Section 2.1 of [RFC9256].
Color (length: 4 octets) Color (length: 4 octets)
The Color field identifies the color of the SR Policy and is The Color field identifies the color of the SR Policy and is
encoded as specified in Section 2.1 of [RFC9256]. encoded as specified in Section 2.1 of [RFC9256].
Endpoint (length: 16 octets) Endpoint (length: 16 octets)
The Endpoint field specifies the endpoint IPv6 address of the SR The Endpoint field specifies the endpoint IPv6 address of the SR
Policy, as defined in Section 2.1 of [RFC9256]. Policy, as defined in Section 2.1 of [RFC9256].
Protocol-Origin (length: 1 octet) Protocol-Origin (length: 1 octet)
The Protocol-Origin field indicates the protocol that originated The Protocol-Origin field indicates the protocol that originated
the SR Candidate Path. It is defined in Section 2.3 of [RFC9256] the SR Candidate Path. It is defined in Section 2.3 of [RFC9256]
and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an and takes values from the IANA registry [PROTOCOL-ORIGIN]. If an
unsupported value is used, validation at the responder MUST fail. unsupported value is used, validation at the responder MUST fail.
Reserved (length: 3 octets) Reserved (length: 3 octets)
The Reserved field is reserved for future use. It MUST be set to The Reserved field is reserved for future use. It MUST be set to
zero when transmitted and MUST be ignored upon receipt. zero when transmitted and MUST be ignored upon receipt.
Originator (length: 20 octets) Originator (length: 20 octets)
The Originator field identifies the originator of the SR Candidate The Originator field identifies the originator of the SR Candidate
Path and is defined in Section 2.4 of [RFC9256]. Path and is defined in Section 2.4 of [RFC9256].
Discriminator (length: 4 octets) Discriminator (length: 4 octets)
The Discriminator field uniquely identifies the SR Candidate Path The Discriminator field uniquely identifies the SR Candidate Path
within the context of the Headend, Color, and Endpoint. This within the context of the Headend, Color, and Endpoint fields.
field is defined in Section 2.5 of [RFC9256]. This field is defined in Section 2.5 of [RFC9256].
Segment-List-ID (length: 4 octets) Segment-List-ID (length: 4 octets)
The Segment-List-ID field is a 4-octet identifier that uniquely The Segment-List-ID field is a 4-octet identifier that uniquely
identifies a segment list within the context of the candidate path identifies a segment list within the context of the candidate path
of an SR Policy. This field is defined in terminology of of an SR Policy. This field is defined in Section 2.2.
Section 2.2.
4. PSID FEC Validation 4. PSID FEC Validation
The MPLS LSP Ping procedures may be initiated by the headend of the The MPLS LSP Ping procedures may be initiated by the headend of the
Segment Routing path or a centralized topology-aware data plane SR path or a centralized topology-aware data plane monitoring system
monitoring system as described in [RFC8403]. For the PSID, the as described in [RFC8403]. For the PSID, the responder nodes that
responder nodes that receive echo request and send echo reply MUST be receive an echo request and send an echo reply MUST be the endpoint
the endpoint of the SR path. of the SR path.
When an endpoint receives the LSP echo request packet with top FEC When an endpoint receives the LSP echo request packet with the top
being the PSID, it MUST perform validity checks on the content of the FEC being the PSID, it MUST perform validity checks on the content of
PSID FEC Stack sub-TLV. the PSID Target FEC Stack sub-TLV.
If a malformed FEC Stack sub-TLV is received, then a return code of If a malformed Target FEC Stack sub-TLV is received, then a return
1, "Malformed echo request received" as defined in [RFC8029] MUST be code of 1, "Malformed echo request received" as defined in [RFC8029]
sent. The section below is appended to step 4a of Section 7.4 of MUST be sent. The section below is appended to step 4a of
[RFC8287]. Section 7.4 of [RFC8287].
4.1. PSID FEC Validation Rules 4.1. PSID FEC Validation Rules
4b. Segment Routing PSID Validation: 4b. Segment Routing PSID Validation:
If the Label-stack-depth is 1 and the Target FEC Stack sub-TLV at If the Label-stack-depth is 1 and the Target FEC Stack sub-TLV at
FEC-stack-depth is TBD1 (SR Policy Associated PSID - IPv4 sub-TLV), { FEC-stack-depth is 49 (SR Policy Associated PSID - IPv4 sub-TLV), {
Set the Best-return-code to 10, "Mapping for this FEC is not the Set the Best-return-code to 10 "Mapping for this FEC is not the
given label at stack-depth <RSC>" if any below conditions fail given label at stack-depth <RSC>" if any below conditions fail
(the notation <RSC> refers to the Return Subcode): (the notation <RSC> refers to the Return Subcode):
- Validate that the PSID is signaled or provisioned for the SR - Validate that the PSID is signaled or provisioned for the SR
Policy { Policy {
o Validate that the signaled or provisioned headend, color, * Validate that the signaled or provisioned headend, color,
and endpoint, for the PSID, matches with the corresponding and endpoint for the PSID match with the corresponding
fields in the received SR Policy Associated PSID - IPv4 sub- fields in the received SR Policy Associated PSID - IPv4
TLV. sub-TLV.
} }
} }
If all the above validations have passed, set the return code to 3 If all the above validations have passed, set the return code to 3
"Replying router is an egress for the FEC at stack-depth <RSC>". "Replying router is an egress for the FEC at stack-depth <RSC>".
Set FEC-Status to 1 and return. Set the FEC-Status to 1 and return.
} }
Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV
at FEC-stack-depth is TBD2 (SR Candidate Path Associated PSID - IPv4 at FEC-stack-depth is 50 (SR Candidate Path Associated PSID - IPv4
sub-TLV), { sub-TLV), {
Set the Best-return-code to 10, "Mapping for this FEC is not the Set the Best-return-code to 10 "Mapping for this FEC is not the
given label at stack-depth <RSC>" if any below conditions fail: given label at stack-depth <RSC>" if any below conditions fail:
- Validate that the PSID is signaled or provisioned for the SR - Validate that the PSID is signaled or provisioned for the SR
Candidate Path { Candidate Path {
o Validate that the signaled or provisioned headend, color, * Validate that the signaled or provisioned headend, color,
endpoint, originator, and discriminator, for the PSID, endpoint, originator, and discriminator for the PSID
matches with the corresponding fields in the received SR match with the corresponding fields in the received SR
Candidate Path Associated PSID - IPv4 sub-TLV. Candidate Path Associated PSID - IPv4 sub-TLV.
} }
} }
If all the above validations have passed, set the return code to 3 If all the above validations have passed, set the return code to 3
"Replying router is an egress for the FEC at stack-depth <RSC>". "Replying router is an egress for the FEC at stack-depth <RSC>".
Set FEC-Status to 1 and return. Set the FEC-Status to 1 and return.
} }
Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV
at FEC-stack-depth is TBD3 (SR Segment List Associated PSID - IPv4 at FEC-stack-depth is 51 (SR Segment List Associated PSID - IPv4
sub-TLV), { sub-TLV), {
Set the Best-return-code to 10, "Mapping for this FEC is not the Set the Best-return-code to 10 "Mapping for this FEC is not the
given label at stack-depth <RSC>" if any below conditions fail: given label at stack-depth <RSC>" if any below conditions fail:
- Validate that the PSID is signaled or provisioned for the SR - Validate that the PSID is signaled or provisioned for the SR
Segment List { Segment List {
o Validate that the signaled or provisioned headend, color, * Validate that the signaled or provisioned headend, color,
endpoint, originator, discriminator, and segment-list-id, endpoint, originator, discriminator, and segment-list-id
for the PSID, matches with the corresponding fields in the for the PSID match with the corresponding fields in the
received SR Segment List Associated PSID - IPv4 sub-TLV. received SR Segment List Associated PSID - IPv4 sub-TLV.
} }
} }
If all the above validations have passed, set the return code to 3 If all the above validations have passed, set the return code to 3,
"Replying router is an egress for the FEC at stack-depth <RSC>". "Replying router is an egress for the FEC at stack-depth <RSC>".
Set FEC-Status to 1 and return. Set the FEC-Status to 1 and return.
} }
Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV
at FEC-stack-depth is TBD4 (SR Policy Associated PSID - IPv6 sub- at FEC-stack-depth is 52 (SR Policy Associated PSID - IPv6
TLV), { sub-TLV), {
Set the Best-return-code to 10, "Mapping for this FEC is not the Set the Best-return-code to 10 "Mapping for this FEC is not the
given label at stack-depth <RSC>" if any below conditions fail given label at stack-depth <RSC>" if any below conditions fail
(the notation <RSC> refers to the Return Subcode):
- Validate that the PSID is signaled or provisioned for the SR - Validate that the PSID is signaled or provisioned for the SR
Policy { Policy {
o Validate that the signaled or provisioned headend, color, * Validate that the signaled or provisioned headend, color,
and endpoint, for the PSID, matches with the corresponding and endpoint for the PSID match with the corresponding
fields in the received SR Policy Associated PSID - IPv6 sub- fields in the received SR Policy Associated PSID - IPv6 sub-
TLV. TLV.
} }
} }
If all the above validations have passed, set the return code to 3 If all the above validations have passed, set the return code to 3
"Replying router is an egress for the FEC at stack-depth <RSC>". "Replying router is an egress for the FEC at stack-depth <RSC>".
Set FEC-Status to 1 and return. Set the FEC-Status to 1 and return.
} }
Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV
at FEC-stack-depth is TBD5 (SR Candidate Path Associated PSID - IPv6 at FEC-stack-depth is 53 (SR Candidate Path Associated PSID - IPv6
sub-TLV), { sub-TLV), {
Set the Best-return-code to 10, "Mapping for this FEC is not the Set the Best-return-code to 10 "Mapping for this FEC is not the
given label at stack-depth <RSC>" if any below conditions fail: given label at stack-depth <RSC>" if any below conditions fail:
- Validate that the PSID is signaled or provisioned for the SR - Validate that the PSID is signaled or provisioned for the SR
Candidate Path { Candidate Path {
o Validate that the signaled or provisioned headend, color, * Validate that the signaled or provisioned headend, color,
endpoint, originator, and discriminator, for the PSID, endpoint, originator, and discriminator for the PSID
matches with the corresponding fields in the received SR match with the corresponding fields in the received SR
Candidate Path Associated PSID - IPv6 sub-TLV. Candidate Path Associated PSID - IPv6 sub-TLV.
} }
} }
If all the above validations have passed, set the return code to 3 If all the above validations have passed, set the return code to 3
"Replying router is an egress for the FEC at stack-depth <RSC>". "Replying router is an egress for the FEC at stack-depth <RSC>".
Set FEC-Status to 1 and return. Set the FEC-Status to 1 and return.
} }
Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV Else, if the Label-stack-depth is 1 and the Target FEC Stack sub-TLV
at FEC-stack-depth is TBD6 (SR Segment List Associated PSID - IPv6 at FEC-stack-depth is 54 (SR Segment List Associated PSID - IPv6
sub-TLV), { sub-TLV), {
Set the Best-return-code to 10, "Mapping for this FEC is not the Set the Best-return-code to 10 "Mapping for this FEC is not the
given label at stack-depth <RSC>" if any below conditions fail: given label at stack-depth <RSC>" if any below conditions fail:
- Validate that the PSID is signaled or provisioned for the SR - Validate that the PSID is signaled or provisioned for the SR
Segment List { Segment List {
o Validate that the signaled or provisioned headend, color, * Validate that the signaled or provisioned headend, color,
endpoint, originator, discriminator, and segment-list-id, endpoint, originator, discriminator, and segment-list-id
for the PSID, matches with the corresponding fields in the for the PSID match with the corresponding fields in the
received SR Segment List Associated PSID - IPv6 sub-TLV. received SR Segment List Associated PSID - IPv6 sub-TLV.
} }
} }
If all the above validations have passed, set the return code to 3 If all the above validations have passed, set the return code to 3
"Replying router is an egress for the FEC at stack-depth <RSC>". "Replying router is an egress for the FEC at stack-depth <RSC>".
Set FEC-Status to 1 and return. Set the FEC-Status to 1 and return.
} }
When an SR Policy Associated PSID - IPv4 sub-TLV, or an SR Candidate When any of the following is carried in a Reverse-Path Target FEC
Path Associated PSID - IPv4 sub-TLV, or an SR Segment List Associated Stack TLV (Type 16) or Reply Path TLV (Type 21), it MUST be sent by
PSID - IPv4 sub-TLV, or an SR Policy Associated PSID - IPv6 sub-TLV, an endpoint in an echo reply.
or an SR Candidate Path Associated PSID - IPv6 sub-TLV, or an SR
Segment List Associated PSID - IPv6 sub-TLV is carried in Reverse- * SR Policy Associated PSID - IPv4 sub-TLV,
Path Target FEC Stack TLV (Type 16) or Reply Path TLV (Type 21), it
MUST be sent by an endpoint in an echo reply. The headend MUST * SR Candidate Path Associated PSID - IPv4 sub-TLV,
perform validity checks as described above without setting the return
code. If any of the validations fail, then the headend MUST drop the * SR Segment List Associated PSID - IPv4 sub-TLV,
echo reply and SHOULD log and/or report an error.
* SR Policy Associated PSID - IPv6 sub-TLV,
* SR Candidate Path Associated PSID - IPv6 sub-TLV, or
* SR Segment List Associated PSID - IPv6 sub-TLV
The headend MUST perform validity checks as described above without
setting the return code. If any of the validations fail, then the
headend MUST drop the echo reply and SHOULD log and/or report an
error.
5. Security Considerations 5. Security Considerations
This document defines additional MPLS LSP Ping sub-TLVs and follows This document defines additional MPLS LSP Ping sub-TLVs and follows
the mechanisms defined in [RFC8029]. All the security considerations the mechanisms defined in [RFC8029]. All the security considerations
defined in Section 5 of [RFC8029] apply to this document. The MPLS defined in Section 5 of [RFC8029] apply to this document. The MPLS
LSP Ping sub-TLVs defined in this document do not impose any LSP Ping sub-TLVs defined in this document do not impose any
additional security challenges to be considered. additional security challenges to be considered.
6. IANA Considerations 6. IANA Considerations
IANA is requested to assign six new Target FEC Stack sub-TLVs from IANA has assigned six Target FEC Stack sub-TLVs from the "Sub-TLVs
the "Sub-TLVs for TLV Types 1, 16, and 21" registry [MPLS-LSP-PING] for TLV Types 1, 16, and 21" registry [MPLS-LSP-PING] within the
within the "TLVs" registry of the "Multiprotocol Label Switching "TLVs" registry of the "Multiprotocol Label Switching (MPLS) Label
(MPLS) Label Switched Paths (LSPs) Ping Parameters" registry group. Switched Paths (LSPs) Ping Parameters" registry group. The Standards
The Standards Action range that requires an error message to be Action [RFC8126] range that requires an error message to be returned
returned if the sub-TLV is not recognized (range 0-16383) should be if the sub-TLV is not recognized (range 0-16383) should be used.
used.
+==========+==================================+================+
| Sub-Type | Sub-TLV Name | Reference |
+==========+==================================+================+
| TBD1 | SR Policy Associated PSID - IPv4 | Section 3.1 of |
| | | THIS_DOCUMENT |
+----------+----------------------------------+----------------+
| TBD2 | SR Candidate Path Associated | Section 3.2 of |
| | PSID - IPv4 | THIS_DOCUMENT |
+----------+----------------------------------+----------------+
| TBD3 | SR Segment List Associated PSID | Section 3.3 of |
| | - IPv4 | THIS_DOCUMENT |
+----------+----------------------------------+----------------+
| TBD4 | SR Policy Associated PSID - IPv6 | Section 3.4 of |
| | | THIS_DOCUMENT |
+----------+----------------------------------+----------------+
| TBD5 | SR Candidate Path Associated | Section 3.5 of |
| | PSID - IPv6 | THIS_DOCUMENT |
+----------+----------------------------------+----------------+
| TBD6 | SR Segment List Associated PSID | Section 3.6 of |
| | - IPv6 | THIS_DOCUMENT |
+----------+----------------------------------+----------------+
Table 2: Sub-TLVs for TLV Types 1, 16, and 21 Registry
7. Acknowledgements
The authors would like to acknowledge Loa Andersson, Detao Zhao, Ben +==========+==================================+=============+
Niven-Jenkins, Greg Mirsky, Ketan Talaulikar, James Guichard, Jon | Sub-Type | Sub-TLV Name | Reference |
Geater, Gorry Fairhurst, Bing Liu, Mohamed Boucadair, Eric Vyncke, +==========+==================================+=============+
Gunter Van de Velde, Mahesh Jethanandani, and Andy Smith for their | 49 | SR Policy Associated PSID - IPv4 | Section 3.1 |
thorough review and very helpful comments. | | | of RFC 9884 |
+----------+----------------------------------+-------------+
| 50 | SR Candidate Path Associated | Section 3.2 |
| | PSID - IPv4 | of RFC 9884 |
+----------+----------------------------------+-------------+
| 51 | SR Segment List Associated PSID | Section 3.3 |
| | - IPv4 | of RFC 9884 |
+----------+----------------------------------+-------------+
| 52 | SR Policy Associated PSID - IPv6 | Section 3.4 |
| | | of RFC 9884 |
+----------+----------------------------------+-------------+
| 53 | SR Candidate Path Associated | Section 3.5 |
| | PSID - IPv6 | of RFC 9884 |
+----------+----------------------------------+-------------+
| 54 | SR Segment List Associated PSID | Section 3.6 |
| | - IPv6 | of RFC 9884 |
+----------+----------------------------------+-------------+
The authors would like to acknowledge Yao Liu and Quan Xiong for the Table 2: Sub-TLVs for TLV Types 1, 16, and 21 Registry
very helpful face to face discussion.
8. References 7. References
8.1. Normative References 7.1. Normative References
[MPLS-LSP-PING] [MPLS-LSP-PING]
"Multi-Protocol Label Switching (MPLS) Label Switched IANA, "Multiprotocol Label Switching (MPLS) Label Switched
Paths (LSPs) Ping Parameters", Paths (LSPs) Ping Parameters",
<http://www.iana.org/assignments/mpls-lsp-ping- <http://www.iana.org/assignments/mpls-lsp-ping-
parameters>. parameters>.
[PROTOCOL-ORIGIN] [PROTOCOL-ORIGIN]
"SR Policy Protocol Origin", IANA, "SR Policy Protocol Origin",
<https://www.iana.org/assignments/segment-routing/segment- <https://www.iana.org/assignments/segment-routing>.
routing.xhtml#sr-policy-protocol-origin>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
Aldrin, S., and M. Chen, "Detecting Multiprotocol Label Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
Switched (MPLS) Data-Plane Failures", RFC 8029, Switched (MPLS) Data-Plane Failures", RFC 8029,
DOI 10.17487/RFC8029, March 2017, DOI 10.17487/RFC8029, March 2017,
skipping to change at page 21, line 15 skipping to change at line 890
[RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov, [RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov,
A., and P. Mattes, "Segment Routing Policy Architecture", A., and P. Mattes, "Segment Routing Policy Architecture",
RFC 9256, DOI 10.17487/RFC9256, July 2022, RFC 9256, DOI 10.17487/RFC9256, July 2022,
<https://www.rfc-editor.org/info/rfc9256>. <https://www.rfc-editor.org/info/rfc9256>.
[RFC9545] Cheng, W., Ed., Li, H., Li, C., Ed., Gandhi, R., and R. [RFC9545] Cheng, W., Ed., Li, H., Li, C., Ed., Gandhi, R., and R.
Zigler, "Path Segment Identifier in MPLS-Based Segment Zigler, "Path Segment Identifier in MPLS-Based Segment
Routing Networks", RFC 9545, DOI 10.17487/RFC9545, Routing Networks", RFC 9545, DOI 10.17487/RFC9545,
February 2024, <https://www.rfc-editor.org/info/rfc9545>. February 2024, <https://www.rfc-editor.org/info/rfc9545>.
8.2. Informative References 7.2. Informative References
[I-D.ietf-idr-bgp-ls-sr-policy]
Previdi, S., Talaulikar, K., Dong, J., Gredler, H., and J.
Tantsura, "Advertisement of Segment Routing Policies using
BGP Link-State", Work in Progress, Internet-Draft, draft-
ietf-idr-bgp-ls-sr-policy-17, 6 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-bgp-
ls-sr-policy-17>.
[I-D.ietf-idr-sr-policy-seglist-id]
Lin, C., Cheng, W., Liu, Y., Talaulikar, K., and M. Chen,
"BGP SR Policy Extensions for Segment List Identifier",
Work in Progress, Internet-Draft, draft-ietf-idr-sr-
policy-seglist-id-04, 27 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-sr-
policy-seglist-id-04>.
[I-D.ietf-pce-multipath] [PCE-MULTIPATH]
Koldychev, M., Sivabalan, S., Saad, T., Beeram, V. P., Koldychev, M., Sivabalan, S., Saad, T., Beeram, V. P.,
Bidgoli, H., Yadav, B., Peng, S., and G. S. Mishra, "PCEP Bidgoli, H., Yadav, B., Peng, S., Mishra, G. S., and S.
Extensions for Signaling Multipath Information", Work in Sidor, "Path Computation Element Communication Protocol
Progress, Internet-Draft, draft-ietf-pce-multipath-13, 9 (PCEP) Extensions for Signaling Multipath Information",
April 2025, <https://datatracker.ietf.org/doc/html/draft- Work in Progress, Internet-Draft, draft-ietf-pce-
ietf-pce-multipath-13>. multipath-16, 17 October 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-pce-
multipath-16>.
[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031, Label Switching Architecture", RFC 3031,
DOI 10.17487/RFC3031, January 2001, DOI 10.17487/RFC3031, January 2001,
<https://www.rfc-editor.org/info/rfc3031>. <https://www.rfc-editor.org/info/rfc3031>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>. July 2018, <https://www.rfc-editor.org/info/rfc8402>.
[RFC8403] Geib, R., Ed., Filsfils, C., Pignataro, C., Ed., and N. [RFC8403] Geib, R., Ed., Filsfils, C., Pignataro, C., Ed., and N.
Kumar, "A Scalable and Topology-Aware MPLS Data-Plane Kumar, "A Scalable and Topology-Aware MPLS Data-Plane
Monitoring System", RFC 8403, DOI 10.17487/RFC8403, July Monitoring System", RFC 8403, DOI 10.17487/RFC8403, July
2018, <https://www.rfc-editor.org/info/rfc8403>. 2018, <https://www.rfc-editor.org/info/rfc8403>.
[RFC9703] Hegde, S., Srivastava, M., Arora, K., Ninan, S., and X. [RFC9703] Hegde, S., Srivastava, M., Arora, K., Ninan, S., and X.
Xu, "Label Switched Path (LSP) Ping/Traceroute for Segment Xu, "Label Switched Path (LSP) Ping/Traceroute for Segment
Routing (SR) Egress Peer Engineering (EPE) Segment Routing (SR) Egress Peer Engineering (EPE) Segment
Identifiers (SIDs) with MPLS Data Plane", RFC 9703, Identifiers (SIDs) with MPLS Data Plane", RFC 9703,
DOI 10.17487/RFC9703, December 2024, DOI 10.17487/RFC9703, December 2024,
<https://www.rfc-editor.org/info/rfc9703>. <https://www.rfc-editor.org/info/rfc9703>.
[RFC9857] Previdi, S., Talaulikar, K., Ed., Dong, J., Gredler, H.,
and J. Tantsura, "Advertisement of Segment Routing
Policies Using BGP Link State", RFC 9857,
DOI 10.17487/RFC9857, October 2025,
<https://www.rfc-editor.org/info/rfc9857>.
[SR-SEGLIST-ID]
Lin, C., Cheng, W., Liu, Y., Talaulikar, K., and M. Chen,
"BGP SR Policy Extensions for Segment List Identifier",
Work in Progress, Internet-Draft, draft-ietf-idr-sr-
policy-seglist-id-06, 24 September 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-sr-
policy-seglist-id-06>.
Acknowledgements
The authors would like to acknowledge Loa Andersson, Detao Zhao, Ben
Niven-Jenkins, Greg Mirsky, Ketan Talaulikar, James Guichard, Jon
Geater, Gorry Fairhurst, Bing Liu, Mohamed Boucadair, Éric Vyncke,
Gunter Van de Velde, Mahesh Jethanandani, and Andy Smith for their
thorough review and very helpful comments.
The authors would like to acknowledge Yao Liu and Quan Xiong for the
very helpful face to face discussion.
Authors' Addresses Authors' Addresses
Xiao Min Xiao Min
ZTE Corp. ZTE Corp.
Nanjing Nanjing
China China
Phone: +86 18061680168 Phone: +86 18061680168
Email: xiao.min2@zte.com.cn Email: xiao.min2@zte.com.cn
Shaofu Peng Shaofu Peng
skipping to change at page 22, line 46 skipping to change at line 983
Email: gongliyan@chinamobile.com Email: gongliyan@chinamobile.com
Rakesh Gandhi Rakesh Gandhi
Cisco Systems, Inc. Cisco Systems, Inc.
Canada Canada
Email: rgandhi@cisco.com Email: rgandhi@cisco.com
Carlos Pignataro Carlos Pignataro
Blue Fern Consulting Blue Fern Consulting
United States of America United States of America
Email: carlos@bluefern.consulting, cpignata@gmail.com Email: carlos@bluefern.consulting
 End of changes. 138 change blocks. 
288 lines changed or deleted 259 lines changed or added

This html diff was produced by rfcdiff 1.48.