LSP Ping/Traceroute for Enabled In-situ OAM Capabilities
draft-ietf-mpls-lsp-ping-ioam-conf-state-01
| Document | Type | Active Internet-Draft (mpls WG) | |
|---|---|---|---|
| Authors | Xiao Min , Greg Mirsky , Loa Andersson | ||
| Last updated | 2026-01-23 | ||
| Replaces | draft-xiao-mpls-lsp-ping-ioam-conf-state | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-mpls-lsp-ping-ioam-conf-state-01
MPLS Working Group X. Min
Internet-Draft ZTE Corp.
Intended status: Standards Track G. Mirsky
Expires: 27 July 2026 Ericsson
L. Andersson
Bronze Dragon Consulting
23 January 2026
LSP Ping/Traceroute for Enabled In-situ OAM Capabilities
draft-ietf-mpls-lsp-ping-ioam-conf-state-01
Abstract
This document describes the application of the mechanism of
discovering In-situ OAM (IOAM) capabilities, described in RFC 9359
"Echo Request/Reply for Enabled In Situ OAM (IOAM) Capabilities", in
MPLS networks. The MPLS Node IOAM Information Query functionality
uses the MPLS echo request/reply messages, allowing the IOAM
encapsulating node to discover the enabled IOAM capabilities of each
IOAM transit and IOAM decapsulating node.
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
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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 27 July 2026.
Copyright Notice
Copyright (c) 2026 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
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and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. IOAM Capabilities Query TLV . . . . . . . . . . . . . . . . . 3
3.1. Examples of the IOAM Capabilities Query . . . . . . . . . 4
4. IOAM Capabilities Response TLV . . . . . . . . . . . . . . . 4
4.1. IOAM Capabilities Sub-TLVs . . . . . . . . . . . . . . . 5
4.2. Examples of IOAM Capabilities Response TLV . . . . . . . 6
5. Return Code Field Processing . . . . . . . . . . . . . . . . 8
6. Operational Considerations . . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7.1. TLV assigments . . . . . . . . . . . . . . . . . . . . . 9
7.2. New Sub-TLV registry . . . . . . . . . . . . . . . . . . 10
7.3. Return Code assignment . . . . . . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
10.1. Normative References . . . . . . . . . . . . . . . . . . 12
10.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
MPLS encapsulation for In-situ OAM (IOAM) data is defined in
[I-D.ietf-mpls-mna-ioam], which utilizes MPLS Network Actions (MNA)
techniques ([RFC9789]) to carry IOAM data fields ([RFC9197],
[RFC9326]) in MPLS packets.
As specified in [RFC9359], the echo request/reply can be used by the
IOAM encapsulating node to discover the enabled IOAM capabilities at
IOAM transit and decapsulating nodes.
[RFC8029] defines a probe message called "MPLS echo request", and a
response message called "MPLS echo reply" for returning the result of
the probe.
This document describes the MPLS Node IOAM Information Query
functionality, which uses the MPLS echo request/reply messages,
allowing the IOAM encapsulating node to discover the enabled IOAM
capabilities of each IOAM transit and IOAM decapsulating node.
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[RFC8029] specifies "ping" and "traceroute" modes. In "ping" mode,
the ingress LSR sends a single MPLS echo request with the TTL in the
outermost label stack entry set to 255. The MPLS echo request is
intended to reach the end of the path and only the egress LSR is
expected to respond with the MPLS echo reply. In "traceroute" mode,
the ingress LSR transmits a sequence of MPLS echo requests with the
TTL value being set in successive probe packets to 1, 2, and so on.
Using TTL expiration as the exception mechanism, each LSR is expected
to respond by transmitting an MPLS echo reply.
In an MPLS network, the ingress LSR may also act as the IOAM
encapsulating node. In such a case, a transit LSR acts as the IOAM
transit node, and the egress LSR acts as the IOAM decapsulating node.
Usually, the trace option of IOAM data is needed, the IOAM
encapsulating node requires to query the enabled IOAM capabilities of
each IOAM transit and decapsulating node, then the "traceroute" mode
can be used. In case that only the edge to edge option of IOAM data
is needed, the IOAM encapsulating node requires to query the enabled
IOAM Capabilities of only the IOAM decapsulating node, then the
"ping" mode can be used.
The mechanism specified in this document applies to both point-to-
point (P2P) MPLS LSP and point-to-multipoint (P2MP) MPLS LSP.
2. Conventions Used in This Document
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.
3. IOAM Capabilities Query TLV
The IOAM Capabilities Query TLV presented in Figure 1 is carried as a
TLV of the MPLS Echo Request message:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Query Type (TBA1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. List of IOAM Namespace-IDs .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: IOAM Capabilities Query TLV
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Type: Indicates the IOAM Capabilities Query TLV. The value is TBA1.
Length: The length of the TLV's Value field in octets.
The Value field is a List of IOAM Namespace-IDs, which is also called
IOAM Capabilities Query Container Payload in Section 3.1 of
[RFC9359].
3.1. Examples of the IOAM Capabilities Query
The format of an IOAM Capabilities Query can vary from deployment to
deployment.
In a deployment where only the default Namespace-ID is used, the IOAM
Capabilities Query is depicted as the following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Query Type (TBA1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Zero-padded |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: IOAM Capabilities Query of the Default IOAM Namespace
In a deployment where two Namespace-IDs (Namespace-ID1 and Namespace-
ID2) are used, the IOAM Capabilities Query is depicted as the
following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Query Type (TBA1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID1 | Namespace-ID2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: IOAM Capabilities Query of the Two IOAM Namespaces
4. IOAM Capabilities Response TLV
The IOAM Capabilities Response TLV presented in Figure 4 is carried
as a TLV of the MPLS Echo Reply message:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|IOAM Capa. Response Type (TBA2)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. List of IOAM Capabilities Sub-TLVs .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: IOAM Capabilities Response TLV
Type: Indicates the IOAM Capabilities Response TLV. The value is
TBA2.
Length: The length of the TLV's Value field in octets.
The Value field is a List of IOAM Capabilities Objects, which is also
called IOAM Capabilities Response Container Payload in Section 3.2 of
[RFC9359]. Each IOAM Capabilities Object is encoded in a sub-TLV
format.
4.1. IOAM Capabilities Sub-TLVs
All IOAM Capabilities sub-TLVs (aka Objects) are encapsulated in an
IOAM Capabilities Response TLV of an MPLS Echo Reply message.
Each IOAM Capabilities sub-TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. IOAM Capabilities Object Payload .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: IOAM Capabilities Sub-TLV
Sub-type: Indicates the IOAM Capabilities sub-TLVs. The values are
listed as the following:
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Value Sub-type Name
----- -----------
1 IOAM Pre-allocated Tracing Capabilities Object
2 IOAM Proof of Transit Capabilities Object
3 IOAM Edge-to-Edge Capabilities Object
4 IOAM DEX Capabilities Object
5 IOAM End-of-Domain Object
Length: The length of the sub-TLV's Value field in octets.
The Value field of the IOAM Capabilities sub-TLV is the IOAM
Capabilities Object Payload, which is defined in Sections 3.2.1,
3.2.3, 3.2.4, 3.2.5, and 3.2.6 of [RFC9359].
4.2. Examples of IOAM Capabilities Response TLV
The format of an IOAM Capabilities Response can vary from deployment
to deployment.
In a deployment where only the default Namespace-ID is used, the IOAM
Pre-allocated Tracing Capabilities and IOAM Proof of Transit
Capabilities are enabled at an IOAM transit node, if that IOAM
transit node received an MPLS echo request containing IOAM
Capabilities Query TLV, then the IOAM Capabilities Response TLV
contained in an MPLS echo reply is depicted as the following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|IOAM Capa. Response Type (TBA2)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |W|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Ingress_MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress_if_id (short or wide format) ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | IOAM-POT-Type |SoP| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Example 1 of IOAM Capabilities Response TLV
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In a deployment where two Namespace-IDs (Namespace-ID1 and Namespace-
ID2) are used, for both Namespace-ID1 and Namespace-ID2 the IOAM Pre-
allocated Tracing Capabilities and IOAM Proof of Transit Capabilities
are enabled at an IOAM transit node, if that IOAM transit node
received an MPLS echo request containing IOAM Capabilities Query TLV,
then the IOAM Capabilities Response TLV contained in an MPLS echo
reply is depicted as the following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|IOAM Capa. Response Type (TBA2)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |W|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID1 | Ingress_MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress_if_id (short or wide format) ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID1 | IOAM-POT-Type |SoP| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |W|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID2 | Ingress_MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress_if_id (short or wide format) ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID2 | IOAM-POT-Type |SoP| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Example 2 of IOAM Capabilities Response TLV
Note that multiple sub-TLVs with the same sub-type may be present in
an IOAM Capabilities Response TLV, as long as the Namespace-IDs in
these sub-TLVs are all different.
In a deployment where only the default Namespace-ID is used, the IOAM
Pre-allocated Tracing Capabilities, IOAM Proof of Transit
Capabilities and IOAM Edge-to-Edge Capabilities are enabled at the
IOAM decapsulating node, if that IOAM decapsulating node received an
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MPLS echo request containing IOAM Capabilities Query TLV, then the
IOAM Capabilities Response TLV contained in an MPLS echo reply is
depicted as the following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|IOAM Capa. Response Type (TBA2)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |W|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Ingress_MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress_if_id (short or wide format) ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | IOAM-POT-Type |SoP| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM Capa. Sub-type (3) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | IOAM-E2E-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|TSF| Reserved | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: Example 3 of IOAM Capabilities Response TLV
5. Return Code Field Processing
The Return Code field in the MPLS echo reply MUST be set to (TBA3) No
Matched Namespace-ID if any of the following conditions apply:
* The IOAM Capabilities Query TLV does not include any Namespace-ID.
* None of the contained list of IOAM Namespace-IDs is recognized.
* None of the contained list of IOAM Namespace-IDs is enabled.
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6. Operational Considerations
Section 4 of [RFC9359] provides an operational guide on how to use
echo request/reply for discovering enabled IOAM capabilities at
network nodes, which applies to this document as well. Specifically,
if only the IOAM Edge-to-Edge Option-Type is enabled for an MPLS LSP,
then LSP Ping in "ping" mode would be operated, which means the LSP
ingress node would send a single MPLS echo request to the LSP egress
node for discovering its IOAM Edge-to-Edge Capabilities; if other
IOAM Option-Type than the Edge-to-Edge Option-Type is enabled for an
MPLS LSP, e.g., the IOAM Pre-allocated Trace Option-Type is enabled
for an MPLS LSP, then LSP Ping in "traceroute" mode would be
operated, which means the LSP ingress node would send a sequence of
MPLS echo requests with TTL equal to 1, 2, 3, and so on, until the
LSP ingress node receives an MPLS echo reply sent by the LSP egress
node.
Considering the IOAM function is resource-consuming, in an MPLS
network with high number LSPs, usually not all the LSPs are IOAM
enabled, in that case, the LSP Ping mechanism for IOAM capabilities
discovery would be executed only with the IOAM-enabled LSPs.
7. IANA Considerations
This document does request that IANA assigns two new TLVs, and new
sub-TLV registry for one of the new TLVs, 5 sub-TLVs to initially
populate this registry and a new return code (TBA3).
7.1. TLV assigments
IANA is requested to assign two new TLVs (TBA1 and TBA2) from the
"TLV" registry in the "Multiprotocol Label Switching (MPLS) Label
Switched Paths (LSPs) Ping Parameters" registry group. The TLVs'
values should be assigned from the range of TLVs that require an
error message if the TLV is not recognized. If possible the two
lowest free values should be used for these TLVs.
+======+=========================+===============+==================+
| Type | TLV Name | Reference | Sub-TLV Registry |
+======+=========================+===============+==================+
| TBA1 | IOAM Capabilities Query | This | No Sub-TLVs |
| | | document | |
+------+-------------------------+---------------+------------------+
| TBA2 | IOAM Capabilities | This | Table 3 |
| | Response | document | |
+------+-------------------------+---------------+------------------+
Table 1: New TLVs
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7.2. New Sub-TLV registry
A new sub-TLV registry should be created for the TLV TBA2 created in
Section 6.1.
The registration procedures for this sub-TLV registry shall be:
+=============+==============+=====================================+
| Range | Registration | Note |
| | Procedure | |
+=============+==============+=====================================+
| 0-16383 | Standards | This range is for TLVs that require |
| | Action | an error message if not recognized. |
| | | ([RFC9041], Section 3.1) |
+-------------+--------------+-------------------------------------+
| 16384-31739 | RFC Required | This range is for TLVs that require |
| | | an error message if not recognized. |
| | | ([RFC9041], Section 3.1) |
+-------------+--------------+-------------------------------------+
| 31740-31743 | Experimental | Reserved, not to be assigned. This |
| | Use | range is for TLVs that require an |
| | | error message if not recognized. |
| | | ([RFC9041], Section 3.1) |
+-------------+--------------+-------------------------------------+
| 31744-32767 | First Come | This range is for TLVs that require |
| | First Served | an error message if not recognized. |
| | | ([RFC9041], Section 3.1) |
+-------------+--------------+-------------------------------------+
| 32768-49161 | Standards | This range is for TLVs that can be |
| | Action | silently dropped if not recognized. |
+-------------+--------------+-------------------------------------+
| 49162-64507 | RFC Required | This range is for TLVs that can be |
| | | silently dropped if not recognized. |
+-------------+--------------+-------------------------------------+
| 64508-64511 | Experimental | Reserved, not to be assigned. This |
| | Use | range is for TLVs that can be |
| | | silently dropped if not recognized. |
+-------------+--------------+-------------------------------------+
| 64512-65535 | First Come | This range is for TLVs that can be |
| | First Served | silently dropped if not recognized. |
+-------------+--------------+-------------------------------------+
Table 2: Sub-TLV Registration Procedures
This sub-TLV registry should initially be populated with the
following values.
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+==========+============================+===============+=========+
| Sub-Type | Sub-TLV name | Reference | Comment |
+==========+============================+===============+=========+
| 0 | Reserved | This document | |
+----------+----------------------------+---------------+---------+
| 1 | IOAM Pre-allocated Tracing | This document | |
| | Capabilities Object | | |
+----------+----------------------------+---------------+---------+
| 2 | IOAM Proof of Transit | This document | |
| | Capabilities Object | | |
+----------+----------------------------+---------------+---------+
| 3 | IOAM Edge-to-Edge | This document | |
| | Capabilities Object | | |
+----------+----------------------------+---------------+---------+
| 4 | IOAM DEX Capabilities | This document | |
| | Object | | |
+----------+----------------------------+---------------+---------+
| 5 | IOAM End-of-Domain Object | This document | |
+----------+----------------------------+---------------+---------+
Table 3: New Sub-TLV Registry for TLV TBA2
7.3. Return Code assignment
IANA is requested to assign a new Return Code from the "Return Code"
registry in the "Multiprotocol Label Switching (MPLS) Label Switched
Paths (LSPs) Ping Parameters" registry group as follows:
+=======+=========================+===============+
| Value | Meaning | Reference |
+=======+=========================+===============+
| TBA3 | No Matched Namespace-ID | This document |
+-------+-------------------------+---------------+
Table 4: New Return Code
8. Security Considerations
Security issues discussed in [RFC8029] and [RFC9359] apply to this
document.
This document recommends that the network operators establish
policies that restrict access to MPLS Node IOAM Information Query
functionality. In order to enforce these policies, nodes that
support MPLS Node IOAM Information Query functionality are
RECOMMENDED to support the following configuration options:
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* Enable/disable MPLS Node IOAM Information Query functionality. By
default, MPLS Node IOAM Information Query functionality is
disabled.
* Define enabled Namespace-IDs. By default, all Namespace-IDs
except the default one (i.e., Namespace-ID 0x0000) are disabled.
While applying the MPLS Node IOAM Information Query to P2MP MPLS LSP,
since a single MPLS echo request may trigger multiple echo replies,
there are scaling concerns and some mitigation measures, e.g.,
containing the Echo Jitter TLV in the MPLS echo request, as being
specified in [RFC6425], MAY be applied.
9. Acknowledgements
The authors would like to acknowledge Tarek Saad for his comments on
the idea of using LSP Ping for MPLS IOAM Capabilities Discovery.
The authors would like to acknowledge Adrian Farrel for his
insightful review and comments.
10. References
10.1. Normative References
[I-D.ietf-mpls-mna-ioam]
Gandhi, R., Mirsky, G., Li, T., Song, H., and B. Wen,
"Supporting In Situ Operations, Administration and
Maintenance Using MPLS Network Actions", Work in Progress,
Internet-Draft, draft-ietf-mpls-mna-ioam-04, 20 November
2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
mpls-mna-ioam-04>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC6425] Saxena, S., Ed., Swallow, G., Ali, Z., Farrel, A.,
Yasukawa, S., and T. Nadeau, "Detecting Data-Plane
Failures in Point-to-Multipoint MPLS - Extensions to LSP
Ping", RFC 6425, DOI 10.17487/RFC6425, November 2011,
<https://www.rfc-editor.org/info/rfc6425>.
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[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,
<https://www.rfc-editor.org/info/rfc8029>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC9041] Andersson, L., Chen, M., Pignataro, C., and T. Saad,
"Updating the MPLS Label Switched Paths (LSPs) Ping
Parameters IANA Registry", RFC 9041, DOI 10.17487/RFC9041,
July 2021, <https://www.rfc-editor.org/info/rfc9041>.
[RFC9359] Min, X., Mirsky, G., and L. Bo, "Echo Request/Reply for
Enabled In Situ OAM (IOAM) Capabilities", RFC 9359,
DOI 10.17487/RFC9359, April 2023,
<https://www.rfc-editor.org/info/rfc9359>.
10.2. Informative References
[RFC9197] Brockners, F., Ed., Bhandari, S., Ed., and T. Mizrahi,
Ed., "Data Fields for In Situ Operations, Administration,
and Maintenance (IOAM)", RFC 9197, DOI 10.17487/RFC9197,
May 2022, <https://www.rfc-editor.org/info/rfc9197>.
[RFC9326] Song, H., Gafni, B., Brockners, F., Bhandari, S., and T.
Mizrahi, "In Situ Operations, Administration, and
Maintenance (IOAM) Direct Exporting", RFC 9326,
DOI 10.17487/RFC9326, November 2022,
<https://www.rfc-editor.org/info/rfc9326>.
[RFC9789] Andersson, L., Bryant, S., Bocci, M., and T. Li, "MPLS
Network Actions (MNAs) Framework", RFC 9789,
DOI 10.17487/RFC9789, July 2025,
<https://www.rfc-editor.org/info/rfc9789>.
Authors' Addresses
Xiao Min
ZTE Corp.
Nanjing
China
Phone: +86 18061680168
Email: xiao.min2@zte.com.cn
Min, et al. Expires 27 July 2026 [Page 13]
Internet-Draft LSP Ping for IOAM Capabilities January 2026
Greg Mirsky
Ericsson
United States of America
Email: gregimirsky@gmail.com
Loa Andersson
Bronze Dragon Consulting
Sweden
Email: loa@pi.nu
Min, et al. Expires 27 July 2026 [Page 14]