Internet-Draft | IPv6 Query for IOAM Capabilities | June 2023 |
Min & Mirsky | Expires 28 December 2023 | [Page] |
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.¶
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
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Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved.¶
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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.¶
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.¶
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:¶
ICMPv6 fields:¶
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].¶
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:¶
ICMPv6 fields:¶
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:¶
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¶
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¶
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].¶
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 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.¶
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.¶
This document requests the following IANA actions:¶
Add the following Code to the "Type 139 - ICMP Node Information Query" sub-registry:¶
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:¶
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:¶
Add the following C-types to the "Sub-types - Class TBD6 - IOAM Proof of Transit Capabilities Object" sub-registry:¶
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
Add the following C-types to the "Sub-types - Class TBD7 - IOAM Edge-to-Edge Capabilities Object" sub-registry:¶
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
Add the following C-types to the "Sub-types - Class TBD8 - IOAM DEX Capabilities Object" sub-registry:¶
Add the following to the "ICMP Extension Object Classes and Class Sub-types" registry:¶
Add the following C-types to the "Sub-types - Class TBD9 - IOAM End-of-Domain Object" sub-registry:¶
All codes mentioned above are assigned on a First Come First Serve (FCFS) basis with a range of 0-255.¶
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:¶
In order to protect local resources, implementations SHOULD rate-limit incoming Node IOAM Information Query messages.¶
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.¶