Internet DRAFT - draft-ietf-ippm-ioam-conf-state
draft-ietf-ippm-ioam-conf-state
IPPM Working Group X. Min
Internet-Draft ZTE Corp.
Intended status: Standards Track G. Mirsky
Expires: 25 May 2023 Ericsson
L. Bo
China Telecom
21 November 2022
Echo Request/Reply for Enabled In-situ OAM Capabilities
draft-ietf-ippm-ioam-conf-state-10
Abstract
This document describes a generic format for use in echo request/
reply mechanisms, which can be used within an In situ Operations,
Administration, and Maintenance (IOAM) domain, allowing the IOAM
encapsulating node to discover the enabled IOAM capabilities of each
IOAM transit and IOAM decapsulating node. The generic format is
intended to be used with a variety of data planes such as IPv6, MPLS,
Service Function Chain (SFC) and Bit Index Explicit Replication
(BIER).
Status of This Memo
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This Internet-Draft will expire on 25 May 2023.
Copyright Notice
Copyright (c) 2022 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.
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 5
3. IOAM Capabilities Formats . . . . . . . . . . . . . . . . . . 6
3.1. IOAM Capabilities Query Container . . . . . . . . . . . . 6
3.2. IOAM Capabilities Response Container . . . . . . . . . . 7
3.2.1. IOAM Pre-allocated Tracing Capabilities Object . . . 8
3.2.2. IOAM Incremental Tracing Capabilities Object . . . . 9
3.2.3. IOAM Proof-of-Transit Capabilities Object . . . . . . 10
3.2.4. IOAM Edge-to-Edge Capabilities Object . . . . . . . . 11
3.2.5. IOAM DEX Capabilities Object . . . . . . . . . . . . 12
3.2.6. IOAM End-of-Domain Object . . . . . . . . . . . . . . 12
4. Operational Guide . . . . . . . . . . . . . . . . . . . . . . 13
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
5.1. IOAM SoP Capability Registry . . . . . . . . . . . . . . 14
5.2. IOAM TSF Capability Registry . . . . . . . . . . . . . . 15
6. Security Considerations . . . . . . . . . . . . . . . . . . . 15
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1. Normative References . . . . . . . . . . . . . . . . . . 17
8.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
In situ Operations, Administration, and Maintenance (IOAM) ([RFC9197]
[RFC9326]) defines data fields that record OAM information within the
packet while the packet traverses a particular network domain, called
an IOAM domain. IOAM can complement or replace other OAM mechanisms,
such as ICMP or other types of probe packets.
As specified in [RFC9197], within the IOAM domain, the IOAM data may
be updated by network nodes that the packet traverses. The device
which adds an IOAM header to the packet is called an "IOAM
encapsulating node". In contrast, the device which removes an IOAM
header is referred to as an "IOAM decapsulating node". Nodes within
the domain that are aware of IOAM data and read and/or write and/or
process IOAM data are called "IOAM transit nodes". IOAM
encapsulating or decapsulating nodes can also serve as IOAM transit
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nodes at the same time. IOAM encapsulating or decapsulating nodes
are also referred to as IOAM domain edge devices, which can be hosts
or network devices. [RFC9197] defines four IOAM option types, and
[RFC9326] introduces a new IOAM option type called the Direct Export
(DEX) Option-Type, which is different from the other four IOAM option
types defined in [RFC9197] on how to collect the operational and
telemetry information defined in [RFC9197].
As specified in [RFC9197], IOAM is focused on "limited domains" as
defined in [RFC8799]. In a limited domain, a control entity that has
control over every IOAM device may be deployed. If that's the case,
the control entity can provision both the explicit transport path and
the IOAM header applied to data packet at every IOAM encapsulating
node.
In a case when a control entity that has control over every IOAM
device is not deployed in the IOAM domain, the IOAM encapsulating
node needs to discover the enabled IOAM capabilities at the IOAM
transit and decapsulating nodes. For example, what types of IOAM
tracing data can be added or exported by the transit nodes along the
transport path of the data packet IOAM is applied to. The IOAM
encapsulating node can then add the correct IOAM header to the data
packet according to the discovered IOAM capabilities. Specifically,
the IOAM encapsulating node first identifies the types and lengths of
IOAM options included in the IOAM data fields according to the
discovered IOAM capabilities. Then the IOAM encapsulating node can
add the IOAM header to the data packet based on the identified types
and lengths of IOAM options included in the IOAM data fields. The
IOAM encapsulating node may use NETCONF/YANG or IGP to discover these
IOAM capabilities. However, NETCONF/YANG or IGP has some
limitations:
* When NETCONF/YANG is used in this scenario, each IOAM
encapsulating node (including the host when it takes the role of
an IOAM encapsulating node) needs to implement a NETCONF Client,
each IOAM transit and IOAM decapsulating node (including the host
when it takes the role of an IOAM decapsulating node) needs to
implement a NETCONF Server, the complexity can be an issue.
Furthermore, each IOAM encapsulating node needs to establish
NETCONF Connection with each IOAM transit and IOAM decapsulating
node, the scalability can be an issue.
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* When IGP is used in this scenario, the IGP and IOAM domains don't
always have the same coverage. For example, when the IOAM
encapsulating node or the IOAM decapsulating node is a host, the
availability can be an issue. Furthermore, it might be too
challenging to reflect enabled IOAM capabilities at the IOAM
transit and IOAM decapsulating node if these are controlled by a
local policy depending on the identity of the IOAM encapsulating
node.
This document specifies formats and objects that can be used in the
extension of echo request/reply mechanisms used in IPv6 (including
Segment Routing with IPv6 data plane (SRv6)), MPLS (including Segment
Routing with MPLS data plane (SR-MPLS)), SFC and BIER environments,
which can be used within the IOAM domain, allowing the IOAM
encapsulating node to discover the enabled IOAM capabilities of each
IOAM transit and IOAM decapsulating node.
The following documents contain references to the echo request/reply
mechanisms used in IPv6 (including SRv6), MPLS (including SR-MPLS),
SFC and BIER environments:
* [RFC4443] ("Internet Control Message Protocol (ICMPv6) for the
Internet Protocol Version 6 (IPv6) Specification"), [RFC4620]
("IPv6 Node Information Queries"), [RFC4884] ("Extended ICMP to
Support Multi-Part Messages") and [RFC8335] ("PROBE: A Utility for
Probing Interfaces")
* [RFC8029] ("Detecting Multiprotocol Label Switched (MPLS) Data-
Plane Failures")
* [I-D.ietf-sfc-multi-layer-oam] ("Active OAM for Service Function
Chaining (SFC)")
* [I-D.ietf-bier-ping] ("BIER Ping and Trace")
It is expected that the specification of the instantiation of each of
these extensions will be done in the form of an RFC jointly designed
by the working group that develops or maintains the echo request/
reply protocol and the IETF IP Performance Measurement (IPPM) Working
Group.
Note that in this document the echo request/reply mechanism used in
IPv6 does not mean ICMPv6 Echo Request/Reply [RFC4443], but means
IPv6 Node Information Query/Reply [RFC4620].
Fate sharing is a common requirement for all kinds of active OAM
packets, echo request is among them, in this document that means echo
request is required to traverse a path of IOAM data packet. This
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requirement can be achieved by, e.g., applying same explicit path or
ECMP processing to both echo request and IOAM data packet. Specific
to apply same ECMP processing to both echo request and IOAM data
packet, one possible way is to populate the same value(s) of ECMP
affecting field(s) in the echo request.
2. Conventions
2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2.2. Abbreviations
BIER: Bit Index Explicit Replication
BGP: Border Gateway Protocol
DEX: Direct Export
ECMP: Equal-Cost Multipath
E2E: Edge to Edge
ICMP: Internet Control Message Protocol
IGP: Interior Gateway Protocol
IOAM: In situ Operations, Administration, and Maintenance
LSP: Label Switched Path
MPLS: Multi-Protocol Label Switching
MTU: Maximum Transmission Unit
NTP: Network Time Protocol
OAM: Operations, Administration, and Maintenance
PCEP: Path Computation Element (PCE) Communication Protocol
POSIX: Portable Operating System Interface
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POT: Proof of Transit
PTP: Precision Time Protocol
SR-MPLS: Segment Routing with MPLS data plane
SRv6: Segment Routing with IPv6 data plane
SFC: Service Function Chain
TTL: Time to Live, this is also the Hop Limit field in the IPv6
header
3. IOAM Capabilities Formats
3.1. IOAM Capabilities Query Container
For echo request, IOAM Capabilities Query uses a container which 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 Capabilities Query Container Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. List of IOAM Namespace-IDs .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: IOAM Capabilities Query Container of Echo Request
When this container is present in the echo request sent by an IOAM
encapsulating node, that means the IOAM encapsulating node requests
the receiving node to reply with its enabled IOAM capabilities. If
there is no IOAM capability to be reported by the receiving node,
then this container MUST be ignored by the receiving node, which
means the receiving node MUST send an echo reply without IOAM
capabilities or no echo reply, in the light of whether the echo
request includes other containers than the IOAM Capabilities Query
Container. A list of IOAM Namespace-IDs (one or more Namespace-IDs)
MUST be included in this container in the echo request, and if
present, the Default-Namespace-ID 0x0000 MUST be placed at the
beginning of the list of IOAM Namespace-IDs. The IOAM encapsulating
node requests only the enabled IOAM capabilities that match one of
the Namespace-IDs. Inclusion of the Default-Namespace-ID 0x0000
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elicits replies only for capabilities that are configured with the
Default-Namespace-ID 0x0000.The Namespace-ID has the same definition
as what's specified in Section 4.3 of [RFC9197].
The IOAM Capabilities Query Container has a container header that is
used to identify the type and optionally length of the container
payload, and the container payload (List of IOAM Namespace-IDs) is
zero-padded to align to a 4-octet boundary. Since the Default-
Namespace-ID of 0x0000 is mandated to appear first in the list, any
other occurrences of 0x0000 MUST be disregarded.
The length, structure, and definition of the IOAM Capabilities Query
Container Header depends on the specific deployment environment.
3.2. IOAM Capabilities Response Container
For echo reply, IOAM Capabilities Response uses a container which 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 Capabilities Response Container Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. List of IOAM Capabilities Objects .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: IOAM Capabilities Response Container of Echo Reply
When this container is present in the echo reply sent by an IOAM
transit node or IOAM decapsulating node, that means the IOAM function
is enabled at this node, and this container contains the enabled IOAM
capabilities of the sender. A list of IOAM capabilities objects (one
or more objects) which contains the enabled IOAM capabilities MUST be
included in this container of echo reply except the sender encounters
an error (e.g., no matched Namespace-ID).
The IOAM Capabilities Response Container has a container header that
is used to identify the type and optionally length of the container
payload. The container header MUST be defined such that it falls on
a four-octet boundary.
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The length, structure, and definition of the IOAM Capabilities
Response Container Header depends on the specific deployment
environment.
Based on the IOAM data fields defined in [RFC9197] and [RFC9326], six
types of objects are defined in this document. The same type of
object MAY be present in the IOAM Capabilities Response Container
more than once, only if with a different Namespace-ID.
Similar to the container, each object has an object header that is
used to identify the type and length of the object payload. The
object payload MUST be defined such that it falls on a four-octet
boundary.
The length, structure, and definition of Object Header depends on the
specific deployment environment.
3.2.1. IOAM Pre-allocated Tracing Capabilities Object
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 Pre-allocated Tracing Capabilities Object Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |W|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Ingress_MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress_if_id (short or wide format) ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: IOAM Pre-allocated Tracing Capabilities Object
When this Object is present in the IOAM Capabilities Response
Container, that means the sending node is an IOAM transit node and
the IOAM pre-allocated tracing function is enabled at this IOAM
transit node.
IOAM-Trace-Type field has the same definition as what's specified in
Section 4.4 of [RFC9197].
Reserved field is reserved for future use and MUST be set to zero,
and MUST be ignored when non-zero.
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W flag indicates whether Ingress_if_id is in short or wide format.
The W-bit is set if the Ingress_if_id is in wide format. The W-bit
is clear if the Ingress_if_id is in short format.
Namespace-ID field has the same definition as what's specified in
Section 4.3 of [RFC9197], it MUST be one of the Namespace-IDs listed
in the IOAM Capabilities Query Object of the echo request.
Ingress_MTU field has 16 bits and specifies the MTU (in octets) of
the ingress interface from which the sending node received echo
request.
Ingress_if_id field has 16 bits (in short format) or 32 bits (in wide
format) and specifies the identifier of the ingress interface from
which the sending node received echo request. If the W-bit is
cleared that indicates Ingress_if_id field has 16 bits, then the 16
bits following the Ingress_if_id field are reserved for future use
and MUST be set to zero, and MUST be ignored when non-zero.
3.2.2. IOAM Incremental Tracing Capabilities Object
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 Incremental Tracing Capabilities Object Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |W|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Ingress_MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress_if_id (short or wide format) ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: IOAM Incremental Tracing Capabilities Object
When this Object is present in the IOAM Capabilities Response
Container, that means the sending node is an IOAM transit node and
the IOAM incremental tracing function is enabled at this IOAM transit
node.
IOAM-Trace-Type field has the same definition as what's specified in
Section 4.4 of [RFC9197].
Reserved field is reserved for future use and MUST be set to zero,
and MUST be ignored when non-zero.
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W flag indicates whether Ingress_if_id is in short or wide format.
The W-bit is set if the Ingress_if_id is in wide format. The W-bit
is clear if the Ingress_if_id is in short format.
Namespace-ID field has the same definition as what's specified in
Section 4.3 of [RFC9197], it MUST be one of the Namespace-IDs listed
in the IOAM Capabilities Query Object of the echo request.
Ingress_MTU field has 16 bits and specifies the MTU (in octets) of
the ingress interface from which the sending node received echo
request.
Ingress_if_id field has 16 bits (in short format) or 32 bits (in wide
format) and specifies the identifier of the ingress interface from
which the sending node received echo request. If the W-bit is
cleared that indicates Ingress_if_id field has 16 bits, then the 16
bits following the Ingress_if_id field are reserved for future use
and MUST be set to zero, and MUST be ignored when non-zero.
3.2.3. IOAM Proof-of-Transit Capabilities Object
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 Proof-of-Transit Capabilities Object Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | IOAM-POT-Type |SoP| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: IOAM Proof-of-Transit Capabilities Object
When this Object is present in the IOAM Capabilities Response
Container, that means the sending node is an IOAM transit node and
the IOAM Proof of Transit function is enabled at this IOAM transit
node.
Namespace-ID field has the same definition as what's specified in
Section 4.3 of [RFC9197], it MUST be one of the Namespace-IDs listed
in the IOAM Capabilities Query Object of the echo request.
IOAM-POT-Type field has the same definition as what's specified in
Section 4.5 of [RFC9197].
SoP (Size of POT) field has two bits, which means the size of "PktID"
and "Cumulative" data that are specified in Section 4.5 of [RFC9197].
This document defines SoP as follows:
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0b00 means 64-bit "PktID" and 64-bit "Cumulative" data.
0b01~0b11: Reserved for future standardization
Reserved field is reserved for future use and MUST be set to zero,
and MUST be ignored when non-zero.
3.2.4. IOAM Edge-to-Edge Capabilities Object
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 Edge-to-Edge Capabilities Object Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | IOAM-E2E-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|TSF| Reserved | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: IOAM Edge-to-Edge Capabilities Object
When this Object is present in the IOAM Capabilities Response
Container, that means the sending node is an IOAM decapsulating node
and IOAM edge-to-edge function is enabled at this IOAM decapsulating
node.
Namespace-ID field has the same definition as what's specified in
Section 4.3 of [RFC9197], it MUST be one of the Namespace-IDs listed
in the IOAM Capabilities Query Object of the echo request.
IOAM-E2E-Type field has the same definition as what's specified in
Section 4.6 of [RFC9197].
TSF field specifies the timestamp format used by the sending node.
Aligned with three possible timestamp formats specified in Section 5
of [RFC9197], this document defines TSF as follows:
0b00: PTP truncated timestamp format
0b01: NTP 64-bit timestamp format
0b10: POSIX-based timestamp format
0b11: Reserved for future standardization
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Reserved field is reserved for future use and MUST be set to zero,
and MUST be ignored when non-zero.
3.2.5. IOAM DEX Capabilities Object
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 DEX Capabilities Object Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: IOAM DEX Capabilities Object
When this Object is present in the IOAM Capabilities Response
Container, that means the sending node is an IOAM transit node and
the IOAM direct exporting function is enabled at this IOAM transit
node.
IOAM-Trace-Type field has the same definition as what's specified in
Section 3.2 of [RFC9326].
Namespace-ID field has the same definition as what's specified in
Section 4.3 of [RFC9197], it MUST be one of the Namespace-IDs listed
in the IOAM Capabilities Query Object of the echo request.
Reserved field is reserved for future use and MUST be set to zero,
and MUST be ignored when non-zero.
3.2.6. IOAM End-of-Domain Object
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 End-of-Domain Object Header .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Must Be Zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: IOAM End-of-Domain Object
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When this Object is present in the IOAM Capabilities Response
Container, that means the sending node is an IOAM decapsulating node.
Unless the IOAM Edge-to-Edge Capabilities Object is present, which
also indicates that the sending node is an IOAM decapsulating node,
the End-of-Domain Object MUST be present in the IOAM Capabilities
Response Container sent by an IOAM decapsulating node. When the IOAM
edge-to-edge function is enabled at the IOAM decapsulating node, it's
RECOMMENDED to include only the IOAM Edge-to-Edge Capabilities Object
but not the IOAM End-of-Domain Object.
Namespace-ID field has the same definition as what's specified in
Section 4.3 of [RFC9197], it MUST be one of the Namespace-IDs listed
in the IOAM Capabilities Query Container.
4. Operational Guide
Once the IOAM encapsulating node is triggered to discover the enabled
IOAM capabilities of each IOAM transit and IOAM decapsulating node,
the IOAM encapsulating node will send echo requests that include the
IOAM Capabilities Query Container. First, with TTL equal to 1 to
reach the closest node, which may be an IOAM transit node or not.
Then with TTL equal to 2 to reach the second-nearest node, which also
may be an IOAM transit node or not. And further, increasing by 1 the
TTL every time the IOAM encapsulating node sends a new echo request,
until the IOAM encapsulating node receives an echo reply sent by the
IOAM decapsulating node, which contains the IOAM Capabilities
Response Container including the IOAM Edge-to-Edge Capabilities
Object or the IOAM End-of-Domain Object. As a result, the echo
requests sent by the IOAM encapsulating node will reach all nodes one
by one along the transport path of IOAM data packet. Alternatively,
if the IOAM encapsulating node knows precisely all the IOAM transit
and IOAM decapsulating nodes beforehand, once the IOAM encapsulating
node is triggered to discover the enabled IOAM capabilities, it can
send an echo request to each IOAM transit and IOAM decapsulating node
directly, without TTL expiration.
The IOAM encapsulating node may be triggered by the device
administrator, the network management system, the network controller,
or data traffic. The specific triggering mechanisms are outside the
scope of this document.
Each IOAM transit and IOAM decapsulating node that receives an echo
request containing the IOAM Capabilities Query Container will send an
echo reply to the IOAM encapsulating node. For the echo reply, there
is an IOAM Capabilities Response Container containing one or more
Objects. The IOAM Capabilities Query Container of the echo request
would be ignored by the receiving node unaware of IOAM.
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Note that the mechanism defined in this document applies to all kinds
of IOAM option types, whether the four types of IOAM option defined
in [RFC9197] or the DEX type of IOAM option defined in [RFC9326],
specifically, when applied to the IOAM DEX option, it allows the IOAM
encapsulating node to discover which nodes along the transport path
support IOAM direct exporting and which trace data types are
supported to be directly exported at these nodes.
5. IANA Considerations
This document requests the following IANA Actions.
IANA is requested to create a registry group named "In-Situ OAM
(IOAM) Capabilities Parameters".
This group will include the following registries:
* IOAM SoP Capability
* IOAM TSF Capability
New registries in this group can be created via RFC Required process
as per [RFC8126].
The subsequent subsections detail the registries herein contained.
Considering the Containers/Objects defined in this document would be
carried in different types of Echo Request/Reply messages, such as
ICMPv6 or LSP Ping, it is intended that the registries for Container/
Object Type would be requested in subsequent documents.
5.1. IOAM SoP Capability Registry
This registry defines 4 code points for the IOAM SoP Capability field
for identifying the size of "PktID" and "Cumulative" data as
explained in Section 4.5 of [RFC9197].
A new entry in this registry requires the following fields:
* SoP: size of POT; a two-bit binary field as defined in
Section 3.2.3
* Description: a terse description of the meaning of this SoP value
The registry initially contains the following value:
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SoP Description
---- -----------
0b00 64-bit "PktID" and 64-bit "Cumulative" data
0b01 - 0b11 are available for assignment via IETF Review process as
per [RFC8126].
5.2. IOAM TSF Capability Registry
This registry defines 4 code points for the IOAM TSF Capability field
for identifying the timestamp format as explained in Section 5 of
[RFC9197].
A new entry in this registry requires the following fields:
* TSF: timestamp format; a two-bit binary field as defined in
Section 3.2.4
* Description: a terse description of the meaning of this TSF value
The registry initially contains the following values:
TSF Description
---- -----------
0b00 PTP Truncated Timestamp Format
0b01 NTP 64-bit Timestamp Format
0b10 POSIX-based Timestamp Format
0b11 is available for assignment via IETF Review process as per
[RFC8126].
6. Security Considerations
Overall, the security needs for IOAM capabilities query mechanisms
used in different environments are similar.
To avoid potential Denial-of-Service (DoS) attacks, it is RECOMMENDED
that implementations apply rate-limiting to incoming echo requests
and replies.
To protect against unauthorized sources using echo request messages
to obtain IOAM Capabilities information, implementations MUST provide
a means of checking the source addresses of echo request messages
against an access list before accepting the message.
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A deployment MUST ensure that border filtering drops inbound echo
requests with an IOAM Capabilities Container Header from outside of
the domain, and drops outbound echo request/replies with IOAM
Capabilities Headers leaving the domain.
A deployment MUST support the configuration option to enable/disable
the IOAM Capabilities Discovery feature defined in this document. By
default, the IOAM Capabilities Discovery feature MUST be disabled.
The integrity protection on IOAM Capabilities information carried in
echo reply messages can be achieved by the underlying transport. For
example, if the environment is an IPv6 network, the IP Authentication
Header [RFC4302] or IP Encapsulating Security Payload Header
[RFC4303] can be used.
The collected IOAM Capabilities information by queries may be
considered confidential. An implementation can use secure underlying
transport of echo request/reply to provide privacy protection. For
example, if the environment is an IPv6 network, confidentiality can
be achieved by using the IP Encapsulating Security Payload Header
[RFC4303].
An implementation can also directly secure the data carried in echo
requests and replies if needed, the specific mechanism on how to
secure the data is beyond the scope of this document.
An implementation can also check whether the fields in received echo
requests and replies strictly conform to the specifications, e.g.,
whether the list of IOAM Namespace-IDs includes duplicate entries,
whether the received Namespace-ID is an operator-assigned or IANA-
assigned one, once a check fails, an exception event indicating the
checked field should be reported to the management.
Except for what's described above, the security issues discussed in
[RFC9197] provide a good guidance on implementation of this
specification.
7. Acknowledgements
The authors would like to acknowledge Tianran Zhou, Dhruv Dhody,
Frank Brockners, Cheng Li, Gyan Mishra, Marcus Ihlar, Martin Duke,
Chris Lonvick, Eric Vyncke, Alvaro Retana, Paul Wouters, Roman
Danyliw, Lars Eggert, Warren Kumari, John Scudder, Robert Wilton,
Erik Kline, Zaheduzzaman Sarker and Murray Kucherawy for their
careful review and helpful comments.
The authors appreciate the f2f discussion with Frank Brockners on
this document.
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The authors would like to acknowledge Tommy Pauly and Ian Swett for
their good suggestion and guidance.
8. References
8.1. Normative References
[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>.
[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>.
[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>.
[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>.
8.2. Informative References
[I-D.ietf-bier-ping]
Kumar, N., Pignataro, C., Akiya, N., Zheng, L., Chen, M.,
and G. Mirsky, "BIER Ping and Trace", Work in Progress,
Internet-Draft, draft-ietf-bier-ping-07, 11 May 2020,
<https://www.ietf.org/archive/id/draft-ietf-bier-ping-
07.txt>.
[I-D.ietf-sfc-multi-layer-oam]
Mirsky, G., Meng, W., Ao, T., Khasnabish, B., Leung, K.,
and G. Mishra, "Active OAM for Service Function Chaining
(SFC)", Work in Progress, Internet-Draft, draft-ietf-sfc-
multi-layer-oam-22, 25 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-sfc-multi-
layer-oam-22.txt>.
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[RFC4302] Kent, S., "IP Authentication Header", RFC 4302,
DOI 10.17487/RFC4302, December 2005,
<https://www.rfc-editor.org/info/rfc4302>.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>.
[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification", STD 89,
RFC 4443, DOI 10.17487/RFC4443, March 2006,
<https://www.rfc-editor.org/info/rfc4443>.
[RFC4620] Crawford, M. and B. Haberman, Ed., "IPv6 Node Information
Queries", RFC 4620, DOI 10.17487/RFC4620, August 2006,
<https://www.rfc-editor.org/info/rfc4620>.
[RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro,
"Extended ICMP to Support Multi-Part Messages", RFC 4884,
DOI 10.17487/RFC4884, April 2007,
<https://www.rfc-editor.org/info/rfc4884>.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
Aldrin, S., Chen, M., and RFC Publisher, "Detecting
Multiprotocol Label Switched (MPLS) Data-Plane Failures",
RFC 8029, DOI 10.17487/RFC8029, March 2017,
<https://www.rfc-editor.org/info/rfc8029>.
[RFC8335] Bonica, R., Thomas, R., Linkova, J., Lenart, C., and M.
Boucadair, "PROBE: A Utility for Probing Interfaces",
RFC 8335, DOI 10.17487/RFC8335, February 2018,
<https://www.rfc-editor.org/info/rfc8335>.
[RFC8799] Carpenter, B. and B. Liu, "Limited Domains and Internet
Protocols", RFC 8799, DOI 10.17487/RFC8799, July 2020,
<https://www.rfc-editor.org/info/rfc8799>.
Authors' Addresses
Xiao Min
ZTE Corp.
Nanjing
China
Phone: +86 25 88013062
Email: xiao.min2@zte.com.cn
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Greg Mirsky
Ericsson
United States of America
Email: gregimirsky@gmail.com
Lei Bo
China Telecom
Beijing
China
Phone: +86 10 50902903
Email: leibo@chinatelecom.cn
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