Internet-Draft | IPv6 Query for IOAM Capabilities | June 2023 |
Min & Mirsky | Expires 28 December 2023 | [Page] |
IPv6 Query for Enabled In-situ OAM Capabilities
Abstract
This document describes the IPv6 Node IOAM Information Query functionality, which uses the IPv6 Node Information messages, allowing the IOAM encapsulating node to discover the enabled IOAM capabilities of each IOAM transit and decapsulating node.¶
This document updates RFCs 4620 and 4884.¶
Status of This Memo
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
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This Internet-Draft will expire on 28 December 2023.¶
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include 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.¶
1. Introduction
IPv6 encapsulation for In-situ OAM (IOAM) data is defined in [I-D.ietf-ippm-ioam-ipv6-options], which uses IPv6 hop-by-hop and destination options to carry IOAM data fields ([RFC9197], [RFC9326]).¶
As specified in [RFC9359], echo request/reply can be used by the IOAM encapsulating node to discover the enabled IOAM capabilities at the IOAM transit and decapsulating nodes.¶
As specified in [RFC4443], the Internet Control Message Protocol for IPv6 (ICMPv6) is an integral part of IPv6, and the base protocol MUST be fully implemented by every IPv6 node. ICMPv6 messages defined in [RFC4443] include error messages and informational messages, and the latter are referred to as ICMPv6 Echo Request/Reply messages. [RFC4884] defines ICMPv6 Extension Structure by which multi-part ICMPv6 error messages are supported. [RFC8335] defines ICMPv6 Extended Echo Request/Reply messages, and the ICMPv6 Extended Echo Request contains an ICMPv6 Extension Structure customized for this message. Both [RFC4884] and [RFC8335] provide sound principles and examples on how to extend ICMPv6 messages.¶
As specified in [RFC4620], two types of IPv6 Node Information messages, the Node Information Query (or NI Query) and the Node Information Reply (or NI Reply), also known as ICMPv6 messages, are used for a Querier node to query information of a Responder node.¶
This document describes the IPv6 Node IOAM Information Query functionality, which uses the IPv6 Node Information messages, allowing the IOAM encapsulating node to discover the enabled IOAM capabilities of each IOAM transit and decapsulating node.¶
The IOAM encapsulating node sends a NI Query to each IOAM transit and decapsulating node, then each receiving node executes access control procedures, and if access is granted, each receiving node returns a NI Reply which indicates the enabled IOAM capabilities of the receiving node. The NI Reply contains an ICMPv6 Extension Structure exactly customized to this message, and the ICMPv6 Extension Structure contains one or more IOAM Capabilities Objects.¶
Note that before the IOAM encapsulating node sends the NI Query, it needs to know the IPv6 address of each node along the transport path of a data packet to which IOAM data would be added. That can be achieved by executing ICMPv6/UDP traceroute or provisioning explicit path at the IOAM encapsulating node. In an Equal-Cost Multipath (ECMP) scenario, the same value or values in any ECMP affecting fields (e.g., the 3-tuple of the Flow Label, Source Address, and Destination Address fields [RFC6437]) of IOAM data packets MUST be populated in the NI Query, ensuring the fate sharing between the NI Query and IOAM data packets.¶
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. Node IOAM Information Query
The Node IOAM Information Query message is encapsulated in an IPv6 header [RFC8200], like any ICMPv6 message.¶
The Node IOAM Information Query message has the following format:¶
IPv6 Header fields:¶
- Source Address: The Source Address identifies the IOAM encapsulating node. It MUST be a valid IPv6 unicast address.¶
- Destination Address: The Destination Address identifies the IOAM transit or decapsulating node. It MUST be a valid IPv6 unicast address.¶
ICMPv6 fields:¶
- Type: NI Query. The value is 139 as allocated for [RFC4620].¶
- Code: The value is (TBD1) the Data field contains a List of IOAM Namespace-IDs which is the Subject of this Query.¶
- Checksum: The ICMPv6 checksum.¶
- Qtype: The value is TBD2, which indicates the NI Query is a node IOAM capabilities query.¶
- Flags: The same as defined in [RFC4620]. Flags are Qtype-specific, the NI Query Qtype used in this document has no defined flags.¶
- Nonce: The same as defined in [RFC4620].¶
- Data: Following the NI Query header, the Data 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 Node IOAM Information Query
The format of a Node IOAM Information Query can vary from deployment to deployment.¶
In a deployment where only the default Namespace-ID is used, the Node IOAM Information Query is depicted as the following:¶
In a deployment where two Namespace-IDs (Namespace-ID1 and Namespace-ID2) are used, the Node IOAM Information Query is depicted as the following:¶
Note that when a Node IOAM Information Query message is received, the message length is indicated by the Payload Length field of IPv6 Header [RFC8200].¶
4. Node IOAM Information Reply
The Node IOAM Information Reply message is encapsulated in an IPv6 header [RFC8200], like any ICMPv6 message.¶
The Node IOAM Information Reply message has the following format:¶
IPv6 Header fields:¶
- Source Address: Copied from the Destination Address field of the invoking Node IOAM Information Query packet.¶
- Destination Address: Copied from the Source Address field of the invoking Node IOAM Information Query packet.¶
ICMPv6 fields:¶
- Type: NI Reply. The value is 140 as allocated for [RFC4620].¶
- Code: The values are (TBD3) No Matched Namespace-ID, and (TBD4) Exceed the minimum IPv6 MTU. See Section 5 for details.¶
- Checksum: The ICMPv6 checksum.¶
- Qtype: Copied from the Qtype field of the invoking Node IOAM Information Query.¶
- Flags: The same as defined in [RFC4620]. Flags are Qtype-specific, the NI Reply Qtype used in this document has no defined flags.¶
- Nonce: Copied from the Nonce field of the invoking Node IOAM Information Query.¶
- Data: Following the NI Reply header, the Data field is a List of IOAM Capabilities Objects, which is also called IOAM Capabilities Response Container payload in Section 3.2 of [RFC9359]. Section 7 of [RFC4884] defines the ICMP Extension Structure. As per RFC 4884, the Extension Structure contains exactly one Extension Header followed by one or more objects. When applied to the Node IOAM Information Reply message, the ICMP Extension Structure MUST contain one or more IOAM Capabilities Objects.¶
4.1. IOAM Capabilities Objects
All ICMPv6 IOAM Capabilities Objects are encapsulated in a Node IOAM Information Reply message.¶
Each ICMPv6 IOAM Capabilities Object has the following format:¶
Object fields:¶
- Class-Num: IOAM Capabilities Objects. The values are listed as the following:¶
Value Object Name ----- ----------- TBD5 IOAM Tracing Capabilities Object TBD6 IOAM Proof of Transit Capabilities Object TBD7 IOAM Edge-to-Edge Capabilities Object TBD8 IOAM DEX Capabilities Object TBD9 IOAM End-of-Domain Object¶
- C-Type: Values are listed as the following:¶
Class-Num C-Type C-Type Name --------- ------ ----------- TBD5 0 Reserved 1 Pre-allocated Tracing TBD6 0 Reserved TBD7 0 Reserved TBD8 0 Reserved TBD9 0 Reserved¶
- Length: Length of the object, measured in octets, including the Object Header and payload.¶
- Object payload: Following the IOAM Capabilities Object Header, it's the IOAM Capabilities Object payload, which is defined respectively in Section 3.2.1, Section 3.2.3, Section 3.2.4, Section 3.2.5 and Section 3.2.6 of [RFC9359].¶
4.2. Examples of the Node IOAM Information Reply
The format of a Node IOAM Information Reply 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 the IOAM transit node that received a Node IOAM Information Query, the Node IOAM Information Reply is depicted as the following:¶
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 the IOAM transit node that received a Node IOAM Information Query, the Node IOAM Information Reply is depicted as the following:¶
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 that received a Node IOAM Information Query, the Node IOAM Information Reply is depicted as the following:¶
Note that when a Node IOAM Information Reply message is received, the message length is indicated by the Payload Length field of IPv6 Header [RFC8200].¶
5. Code Field Processing
The Code field in the Node IOAM Information Reply MUST be set to (TBD3) No Matched Namespace-ID if any of the following conditions apply:¶
- The Node IOAM Information Query 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.¶
The Code field in the Node IOAM Information Reply MUST be set to (TBD4) Exceed the minimum IPv6 MTU if the formatted NI Reply packet exceeds the minimum IPv6 MTU (i.e., 1280 octets). In this case, all objects MUST be stripped before forwarding the Node IOAM Information Reply to its destination.¶
6. Updates to RFC 4884
Section 4.6 of [RFC4884] provides a list of extensible ICMP messages (i.e., messages that can carry the ICMP Extension Structure). This document adds the IPv6 Node Information Query message and the IPv6 Node Information Reply message to that list.¶
7. IANA Considerations
This document requests the following IANA actions:¶
-
Add the following Code to the "Type 139 - ICMP Node Information Query" sub-registry:¶
- (TBD1) The Data field contains a List of IOAM Namespace-IDs which is the Subject of this Query¶
-
Add the following Codes to the "Type 140 - ICMP Node Information Response" sub-registry:¶
-
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
- (TBD5) IOAM Tracing Capabilities Object¶
-
Add the following C-types to the "Sub-types - Class TBD5 - IOAM Tracing Capabilities Object" sub-registry:¶
-
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
- (TBD6) IOAM Proof of Transit Capabilities Object¶
-
Add the following C-types to the "Sub-types - Class TBD6 - IOAM Proof of Transit Capabilities Object" sub-registry:¶
- (0) Reserved¶
-
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
- (TBD7) IOAM Edge-to-Edge Capabilities Object¶
-
Add the following C-types to the "Sub-types - Class TBD7 - IOAM Edge-to-Edge Capabilities Object" sub-registry:¶
- (0) Reserved¶
-
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
- (TBD8) IOAM DEX Capabilities Object¶
-
Add the following C-types to the "Sub-types - Class TBD8 - IOAM DEX Capabilities Object" sub-registry:¶
- (0) Reserved¶
-
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
- (TBD9) IOAM End-of-Domain Object¶
-
Add the following C-types to the "Sub-types - Class TBD9 - IOAM End-of-Domain Object" sub-registry:¶
- (0) Reserved¶
All codes mentioned above are assigned on a First Come First Serve (FCFS) basis with a range of 0-255.¶
8. Security Considerations
Securiy issues discussed in [RFC4620] and [RFC9359] apply to this document.¶
This document recommends using IP Authentication Header [RFC4302] or IP Encapsulating Security Payload Header [RFC4303] to provide integrity protection for IOAM capabilities information.¶
This document recommends using IP Encapsulating Security Payload Header [RFC4303] to provide privacy protection for IOAM capabilities information.¶
This document recommends that the network operators establish policies that restrict access to IPv6 Node IOAM Information Query functionality. In order to enforce these policies, nodes that support IPv6 Node IOAM Information Query functionality MUST support the following configuration options:¶
- Enable/disable IPv6 Node IOAM Information Query functionality. By default, IPv6 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.¶
- For each enabled Namespace-ID, define the prefixes from which Node IOAM Information Query messages are permitted.¶
In order to protect local resources, implementations SHOULD rate-limit incoming Node IOAM Information Query messages.¶
9. Acknowledgements
The authors would like to acknowledge Eric Vyncke and Erik Kline for their valuable suggestions on using IPv6 Node Information Queries as the basis.¶
The authors would like to acknowledge Bob Hinden for his valuable suggestions on the ICMPv6 message format.¶
The authors would like to acknowledge Chongfeng Xie and Zhenqiang Li for their review and helpful comments.¶
10. References
10.1. Normative References
- [I-D.ietf-ippm-ioam-ipv6-options]
- Bhandari, S. and F. Brockners, "In-situ OAM IPv6 Options", Work in Progress, Internet-Draft, draft-ietf-ippm-ioam-ipv6-options-12, , <https://datatracker.ietf.org/doc/html/draft-ietf-ippm-ioam-ipv6-options-12>.
- [RFC2119]
- Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
- [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, , <https://www.rfc-editor.org/info/rfc4443>.
- [RFC4620]
- Crawford, M. and B. Haberman, Ed., "IPv6 Node Information Queries", RFC 4620, DOI 10.17487/RFC4620, , <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, , <https://www.rfc-editor.org/info/rfc4884>.
- [RFC8174]
- Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
- [RFC9359]
- Min, X., Mirsky, G., and L. Bo, "Echo Request/Reply for Enabled In Situ OAM (IOAM) Capabilities", RFC 9359, DOI 10.17487/RFC9359, , <https://www.rfc-editor.org/info/rfc9359>.
10.2. Informative References
- [RFC4302]
- Kent, S., "IP Authentication Header", RFC 4302, DOI 10.17487/RFC4302, , <https://www.rfc-editor.org/info/rfc4302>.
- [RFC4303]
- Kent, S., "IP Encapsulating Security Payload (ESP)", RFC 4303, DOI 10.17487/RFC4303, , <https://www.rfc-editor.org/info/rfc4303>.
- [RFC6437]
- Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, "IPv6 Flow Label Specification", RFC 6437, DOI 10.17487/RFC6437, , <https://www.rfc-editor.org/info/rfc6437>.
- [RFC8200]
- Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, , <https://www.rfc-editor.org/info/rfc8200>.
- [RFC8335]
- Bonica, R., Thomas, R., Linkova, J., Lenart, C., and M. Boucadair, "PROBE: A Utility for Probing Interfaces", RFC 8335, DOI 10.17487/RFC8335, , <https://www.rfc-editor.org/info/rfc8335>.
- [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, , <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, , <https://www.rfc-editor.org/info/rfc9326>.