Internet-Draft ICMP E-Impact Extensions April 2024
Pignataro, et al. Expires 7 October 2024 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-pignataro-eimpact-icmp-02
Published:
Intended Status:
Experimental
Expires:
Authors:
C. Pignataro
NC State University
J. Parikh
NC State University
R. Bonica
Juniper
M. Welzl
University of Oslo

ICMP Extensions for Environmental Information

Abstract

This document defines a data structure that can be appended to selected ICMP messages. The ICMP extension defined herein can be used to gain visibility on environmental impact information on the Internet by providing per-hop (i.e., per topological network node) power metrics and other current or future sustainability metrics. This will contribute to achieving an objective mentioned in the IAB E-Impact workshop.

The techniques presented are useful not only in a transactional setting (e.g., a user-issued traceroute or a ping request), but also in a scheduled automated setting where they may be run periodically in a mesh across an administrative domain to map out environmental-impact metrics.

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/.

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 7 October 2024.

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Table of Contents

1. Introduction

IP devices use the Internet Control Message Protocol ICMPv4 [RFC0792] and ICMPv6 [RFC4443] to convey control information to source hosts. In particular, when an IP device receives a datagram that it cannot process, it may send an ICMP message to the datagram's originator or source. Network operators and higher-level protocols use these ICMP messages to detect and diagnose network issues.

As the world transitions towards sustainability in technology, the focus is shifting not only on creating modern technologies infused with sustainability but also on bridging gaps in the tools that are already available, to enhance visibility, measurement, and quantification of their impact. Consequently, tools which have been foundational for control and management for decades now encounter new requirements including enhancing them to cater to a significantly increasing demand for monitoring the sustainability and environmental impact. This document serves that need by defining an ICMP extension object that appends environmental impact information to ICMP messages.

Using the extension defined herein, a device can explicitly append these exemplary environmental impact metrics for transmission across an administrative domain:

2. Conventions

2.1. Definition of Terms

This document uses the following terms:

ICMP:

Generically referring to ICMPv4 [RFC0792] and ICMPv6 [RFC4443] messages.
ICMP Extension:

Extended ICMP to support multi-part messages through an ICMP extension structure, as defined in [RFC4884].

2.2. 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.

3. Application

The IAB held a workshop on "Environmental Impact of Internet Applications and Systems (eimpactws)" [IAB-EIMPACTWS], in which the need for visibility into environmental impact metrics within traditional Internet tools such as traceroute was highlighted (see WebVTT cue identifiers 139 and 140 of [IAB-EIMPACTWS-Minutes].)

The Environmental Information ICMP Extensions defined in this document allow for augmenting the traceroute output with environmental metrics from each reported node.

4. Transport Options for Sustainability Information

To achieve the goal of transporting useful sustainability information across the network, there are two key considerations. First, what information is useful to convey and in what format, and second, how to transport that sustainability information.

For the first task, it is critical to normalize and agree upon the information to convey and format, across potentially multiple transports.

For the second task, there is a variety of options available depending on use cases. These can be categorized based on whether the approach is distributed (i.e., any endpoint or node can request and/or receive the sustainability information) or centralized (i.e., a single 'controller' compiles and consolidates the information.) They can also be categorized based on the networking layer used (e.g., IP, like ICMP, or application, like SNMP). Further, an existing protocol can be extended, or a brand new protocol can potentially be created for this purpose.

This document builds upon a standardized, modular, backwards-compatible, and scale-proven ICMP extension [RFC4884]. This does not preclude the definition of other methods to transport sustainability information, more fitting to other use-cases.

5. ICMP Environmental Information Extension

This section defines the Environmental Information Object, an ICMP extension object with a Class-Num (Object Class Value) of TBA that can be appended to the following messages, as per [RFC4884] and [RFC8335]:

The ICMP extension defined in this document MAY be appended to any of the above listed messages based on policy and following security considerations.

These extensions are preceded by an ICMP Extension Structure Header, and include an ICMP Object Header. Both are defined in [RFC4884]. The same backward compatibility issues that apply to [RFC4884] apply to this extension.

A single ICMP message can contain zero, one, or multiple instances of Environmental Information Objects. The C-Type further identifies the information fields carried.

A single instance of the Environmental Information Object can convey one of the information elements defined in Section 5.2 from each reporting node in an administrative domain.

5.1. Extension Format

The ICMP Environmental Information Extension has the following format.

                     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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...
|Version|       Reserved        |           Checksum            |(1)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...
|             Length            |   Class-Num   |   C-Type      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+(2)
~                        Object payload                         ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...
Figure 1: ICMP Environmental Information Extension Format
(1) ICMP Extension Header
Version:

2 [RFC4884].
Reserved:

0 [RFC4884].
Checksum:

The one's complement checksum of the ICMP extension [RFC4884].
(2) Environmental Information Object
Length:

Length of the object, including header and payload, in octets.
Class-Num:

TBA (Environmental Information)
C-Type:

C-Type as explained in Section 5.2.
Object Payload:

As defined by each C-Type.

While there is a single ICMP Extension Header, there could be multiple Environmental Information Objects.

5.2. C-Type Definition

The 8-bit C-Type defined in the Section 8 of [RFC4884] allows to carry different information elements within this Class-Num (TBA). The techniques herein defined can be used with any specific e-impact metric in use, current or future.

The ICMP Environmental Information Extension Object header has the following format:

                     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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|             Length            | Class-Num=TBA | C-Type=1-255  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Environmental Information Extension Object Header

The following C-Type values are currently defined.

  1. Node Power Draw Sub-Object

                         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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                Power (32-bit unsigned word)                   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Figure 3: Node Power Draw Sub-Object

    A Class-Num of TBA and a C-Type of 1 are specified.

    The Length is always 8.

    The returned value is the node-level current power being drawn, which is a magnitude that may be directly displayed, and is expressed in Watts (W).

  2. Node Throughput Sub-Object

                         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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|              Throughput (32-bit unsigned word)                |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Figure 4: Node Throughput Sub-Object

    A Class-Num of TBA and a C-Type of 2 are specified.

    The Length is always 8.

    The returned value is the node-level current throughput, which is a magnitude that may be directly displayed, and is expressed in bits-per-second (BPS). This allows the recipient of the ICMP message to determine a relationship between power and traffic load.

  3. Ecolabels and Environmentally Relevant Certification (EERC) Sub-Object

                         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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         EERC number           |0 0 0 0|          Year         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Figure 5: EERC Sub-Object

    A Class-Num of TBA and a C-Type of 3 are specified.

    The Length is always 8.

    The returned value references an Ecolabels and Environmentally Relevant Certification (EERC) number. The following EERC numbers are defined by the present specification:

    1. ISO 14001:2015

    2. TCO Certified

    3. Energy-efficient ethernet

    The "Year" field must contain the year in which the certificate was issued, or 0 to indicate "unknown" or "not specified".

  4. Component-level Power Draw Sub-Object

                         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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      UUID 32-bit Word 1                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      UUID 32-bit Word 2                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      UUID 32-bit Word 3                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      UUID 32-bit Word 4                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                Component Power (32-bit word)                  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Figure 6: Component-level Power Draw Element

    A Class-Num of TBA and a C-Type of 4 are specified.

    The Length is always 4 plus 20 times the number of elements included.

    The returned value is one or more instances of component-level power drawn metrics. Each instance is a set comprised by a UUID uniquely indentifying the component, and the actual power being drawn by said component expressed in Watts (W).

6. Sample Use Case

The ICMP extension defined in this memo can be used to get sustainability metrics, either via a "transactional" or a "scheduled automated" fashion, inside an administrative domain. Mentioned in this section is a sample "transactional" use case of how these metrics could be displayed to a user. Since both traceroute and ping utilities are based on ICMP, we will use traceroute as an example.

The flavor of traceroute that has been shown here supports the ICMP extensions and is capable of conveying to the end user the sustainability metrics in the extensions, along with the nodes that the original datagram visited on its way to the destination. This traceroute is also backwards-compatible, i.e., it can also work well with those nodes which do not support these ICMP extensions.

A user at a host with IP an address 198.51.100.27 executes a traceroute to 192.0.2.1 and the Figure 7 shows how the user can be presented with these metrics:

> traceroute 192.0.2.1
Tracing route to 192.0.2.1 over a maximum of 30 hops

  1     3 ms     1 ms     2 ms  203.0.113.118
       Power(Node=160W,Fan=7W,Chassis=10W)
       Throughput(53687091200bps)
       EERC(ISO 14001:2015, Energy-efficient ethernet)

  2    12 ms     9 ms     9 ms  192.0.2.9
       Power(Node=163W,Fan=8W,Chassis=11W)
       Throughput(55834574848bps)
       EERC(ISO 14001:2015)

  3    12 ms     9 ms     9 ms  192.0.2.17

  4     7 ms     4 ms     7 ms  192.0.2.122
       Power(Node=150W,Fan=6W,Chassis=9W)
       Throughput(51539607552bps)
       EERC(ISO 14001:2015, Energy-efficient ethernet)

  5     4 ms     3 ms     3 ms  192.0.2.1

Trace complete.
Figure 7: Sustainability-Metrics Infused Traceroute

7. Security Considerations

The security considerations of [RFC4884] and of [RFC8335] apply to these extensions.

Upon receipt of an ICMP message, application software must check it for syntactic correctness. The extension checksum MUST be verified. Care should be taken, as improperly specified length attributes and other syntax problems may result in buffer overruns.

This document does not define the conditions under which a router sends an ICMP message. Therefore, it does not expose routers to any new denial-of-service attacks. Routers may need to limit the rate at which ICMP messages are sent.

This document defines an extension that allows a router to append environmental impact information to multi-part ICMP messages in a single administrative domain, and therefore can provide the user of the traceroute and ping applications with additional metrics.

The intended field of use for the extensions defined in this document is administrative debugging and troubleshooting and operational facilities. The extensions herein defined supply additional information in ICMP responses. These mechanisms are not initially intended for other uses.

Some of the additional metrics provided, as e.g., power draw information, have privacy considerations. For example, behavioral considerations of the devices, or estimating other node and network attributes from the power or energy data. Other things like identification of the node, deducing node usage patterns are some more privacy concerns that can be related to the metrics.

Keeping these considerations in mind, we limited the scope of the transportation of the sustainability metrics to a single administrative domain. But, based on [RFC8799], limiting a protocols functionality doesn't mean that it will be secure. So, this particular document, which defines "a modified ICMP message with sustainability metrics", can be classified as a FAIL-OPEN protocol [I-D.wkumari-intarea-safe-limited-domains]. That is, the interfaces of administrative domain border nodes, facing towards the open internet, can be configured such that they avoid leaking messages with extensions containing sustainability metrics, out of the AD. To allow general ICMP messages, an administrator can configure those outward facing interfaces to not block/drop the entire message but only strip off the extension objects and only forward the ICMP message if it is destined to go out of the AD.

When metrics are limited to the same AD, it can be considered that they can be generated from a valid source and will have integrity.

This document does not specify an authentication mechanism for the extension that it defines. Application developers should be aware of various ICMP attacks [RFC5927].

8. IANA Considerations

IANA is requested to assign the following object Class-num in the ICMP Extension Object Classes and Class Sub-types registry [IANA-ICMP-Extended]:

Table 1: Class-num for Environmental Information Extensions
Class Value Class name Reference
TBA Environmental Information Object This document

IANA is requested to establish a registry for the corresponding class sub-type (C-Type) space, as follows:

Table 2: C-Types for Environmental Information Extensions
C-Type Value Description Reference
0 Reserved This document
1 Node Power Draw This document
2 Node Throughput This document
3 Ecolabels and Environmentally Relevant Certification (EERC) This document
4 Component-level Power Draw This document
2-246 Unassigned  
247-255 Reserved for Experimentation This document

C-Type values are assignable on a first-come-first-serve (FCFS) basis.

IANA is requested to establish a registry for Ecolabels and Environmentally Relevant Certification (EERC) numbers (C-Type 2), as follows:

Table 3: EERC numbers
Number Name Reference
0 Reserved  
1 ISO 14001:2015 This document
2 TCO Certified This document
3 Energy-efficient ethernet This document
4-65527 Unassigned  
65528-65535 Reserved for Experimentation This document

EERC numbers are assignable on a first-come-first-serve (FCFS) basis.

9. Acknowledgements

We are very grateful to Jari Arkko for his thorough review and most useful set of comments and suggestions. We are also appreciative of the feedback, input, and interest from participants of the eimpact 2024 Interim meeting.

10. References

10.1. Normative References

[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>.
[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>.
[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>.

10.2. Informative References

[I-D.wkumari-intarea-safe-limited-domains]
Kumari, W. A., Alston, A., Vyncke, E., and S. Krishnan, "Safe(r) Limited Domains", Work in Progress, Internet-Draft, draft-wkumari-intarea-safe-limited-domains-00, , <https://datatracker.ietf.org/doc/html/draft-wkumari-intarea-safe-limited-domains-00>.
[IAB-EIMPACTWS]
"IAB workshop on Environmental Impact of Internet Applications and Systems (eimpactws)", , <https://datatracker.ietf.org/group/eimpactws/>.
[IAB-EIMPACTWS-Minutes]
"Minutes for the IAB E-Impact Workshop Session 4: Next Steps", eimpactws Session 4, , <https://datatracker.ietf.org/doc/minutes-interim-2022-eimpactws-04-202212121400/>.
[IANA-ICMP-Extended]
"Internet Control Message Protocol (ICMP) Parameters, ICMP Extension Object Classes and Class Sub-types", <https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-ext-classes>.
[RFC0792]
Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, DOI 10.17487/RFC0792, , <https://www.rfc-editor.org/info/rfc792>.
[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>.
[RFC5927]
Gont, F., "ICMP Attacks against TCP", RFC 5927, DOI 10.17487/RFC5927, , <https://www.rfc-editor.org/info/rfc5927>.
[RFC8799]
Carpenter, B. and B. Liu, "Limited Domains and Internet Protocols", RFC 8799, DOI 10.17487/RFC8799, , <https://www.rfc-editor.org/info/rfc8799>.

Authors' Addresses

Carlos Pignataro
North Carolina State University
United States of America
Jainam Parikh
North Carolina State University
United States of America
Ron Bonica
Juniper Networks
United States of America
Michael Welzl
University of Oslo
Norway