Network Working Group                                       C. Pignataro
Internet-Draft                                                 J. Parikh
Intended status: Experimental                        NC State University
Expires: 1 July 2025                                           R. Bonica
                                                                 Juniper
                                                                M. Welzl
                                                      University of Oslo
                                                        28 December 2024


             ICMP Extensions for Environmental Information
                  draft-pignataro-green-enviro-icmp-01

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 sustainability 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
   sustainability 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 1 July 2025.






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Copyright Notice

   Copyright (c) 2024 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Definition of Terms . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  Motivation  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Transport Options for Sustainability Information  . . . . . .   4
   5.  ICMP Environmental Information Extension  . . . . . . . . . .   4
     5.1.  Extension Format  . . . . . . . . . . . . . . . . . . . .   5
     5.2.  C-Type Definition . . . . . . . . . . . . . . . . . . . .   6
   6.  Sub-Object Formats  . . . . . . . . . . . . . . . . . . . . .  11
   7.  Sample Use Case . . . . . . . . . . . . . . . . . . . . . . .  12
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  16
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  16
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  16
     11.2.  Informative References . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18

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 environmental sustainability but also on bridging gaps in the
   tools that are already available, to enhance visibility, measurement,



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   and quantification of their environmental 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
   sustainability information to ICMP messages.  Using ICMP as a medium
   to deliver environmental sustainability information is very apt as
   ICMP is one of the most used protocols for administration and
   troubleshooting and it works effectively not only in an automated
   setting, but also in an on-demand setting for different purposes and
   use cases.

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

   *  Present and idle power (node level, component level)
   *  Throughput (node level, component level)
   *  Ecolabels and Environmentally Relevant Certifications (EERCs)

   Additional environmental sustainability metrics, such as the
   following, for example, may also be specified in the future:

   *  Electrical Energy Provider or Zone
   *  Geolocation

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.



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3.  Motivation

   The IAB held a workshop on "Environmental Impact of Internet
   Applications and Systems (eimpactws)" [IAB-EIMPACTWS], in which the
   need for visibility into environmental sustainability 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]:

   *  ICMPv4 Time Exceeded
   *  ICMPv4 Destination Unreachable
   *  ICMPv4 Parameter Problem



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   *  ICMPv4 Extended Echo Reply [RFC8335]
   *  ICMPv6 Time Exceeded
   *  ICMPv6 Destination Unreachable
   *  ICMPv6 Extended Echo Reply [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:



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         The one's complement checksum of the ICMP extension [RFC4884].

   (2) Environmental Information Object

      Length:
         Length of the Environmental Information object, including
         object header and object payload, in octets.  If there is no
         object payload, the value of Length is 4.  This is used to
         convey that the object is unavailable (e.g., because the
         requested information is not applicable for the type of
         component that is being queried.)

      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
   environmental sustainability 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






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                            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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |            Present Power (32-bit unsigned word)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |             Idle 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 12 if the object contains this payload.  A Length
       value of 4 indicates that it is unavailable.

       The Present Power is the node-level power being presently drawn,
       which is a magnitude that may be directly displayed, and is
       expressed in Watts (W).  A value of 0 indicates that the Present
       Power is not available.  The Idle Power is the node-level power
       when the node is idle.  A value of 0 indicates that the Idle
       Power is not available.

   2.  Node Throughput Short 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 Short Sub-Object

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

       The Length is 8 if the object contains this payload.  A Length
       value of 4 indicates that it is unavailable.

       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.  Node Throughput Wide Sub-Object







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                            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 1)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |             Throughput (32-bit unsigned word 2)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                   Figure 5: Node Throughput Wide Sub-Object

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

       The Length is 12 if the object contains this payload.  A Length
       value of 4 indicates that it is unavailable.

       The returned value is the node-level present 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.

       There's an in-depth discussion on why there are two formats, a
       32-bit "short" and a 64-bit "wide", and when will one be chosen
       over the other, in Section Section 6.

   4.  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 6: EERC Sub-Object

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

       The Length is 8 if the object contains this payload.  A Length
       value of 4 indicates that it is unavailable.

       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 [EERC-ISO14001_2015]

       2.  TCO Certified [EERC-TCO]



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       3.  Energy-efficient ethernet [EERC-EEE]

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

   5.  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                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |       Present Component Power (32-bit unsigned word)          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |        Idle Component Power (32-bit unsigned word)            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 7: Component-level Power Draw Element

       A Class-Num of TBA and a C-Type of 5 are specified.

       The Length is 4 plus 24 times the number of elements included.  A
       Length value of 4 indicates that this object is unavailable.

       The returned value is one or more instances of component-level
       power drawn metrics.  Each instance is a set comprised by a UUID
       [RFC4122] uniquely identifying the component, and the Present
       Component Power and Idle Component Power fields.  The Present
       Component Power is the component-level power being presently
       drawn, which is a magnitude that may be directly displayed, and
       is expressed in Watts (W).  A value of 0 indicates that the
       Present Component Power is not available.  The Idle Component
       Power is the component-level power when the component is idle.  A
       value of 0 indicates that the Idle Component Power is not
       available.

   6.  Component-level Throughput Short Sub-Object








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                            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 Throughput (32-bit word)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 8: Component-level Throughput Short Element

       A Class-Num of TBA and a C-Type of 6 are specified.

       The Length is 4 plus 20 times the number of elements included.  A
       Length value of 4 indicates that this object is unavailable.

       The returned value is one or more instances of component-level
       throughput.  Each instance is a set comprised by a UUID uniquely
       identifying the component, and the actual throughput of said
       component in bits-per-second (BPS).  This allows the recipient of
       the ICMP message to determine a relationship between power and
       traffic load.

   7.  Component-level Throughput Wide 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 Throughput (32-bit word 1)              |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |             Component Throughput (32-bit word 2)              |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

              Figure 9: Component-level Throughput Wide Sub-Object




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       A Class-Num of TBA and a C-Type of 7 are specified.

       The Length is 4 plus 24 times the number of elements included.  A
       Length value of 4 indicates that this object is unavailable.

       The returned value is one or more instances of component-level
       throughput.  Each instance is a set comprised by a UUID uniquely
       identifying the component, and the actual throughput of said
       component in bits-per-second (BPS).  This allows the recipient of
       the ICMP message to determine a relationship between power and
       traffic load.

       A discussion on why there are two formats, a 32-bit "short" and a
       64-bit "wide", and when will one be chosen over the other, can be
       found in Section 6.

6.  Sub-Object Formats

   As discussed in Section 5.2, apart from the 32-bit "short" sub-
   object, we have also defined a 64-bit "wide" format for Node and
   Component throughput Sub-Objects.

   The 64-bit format was defined keeping the present trends of the
   industry in mind.  With the industry shifting towards high density
   ports/components and nodes, organizations now have
   components/interfaces/line cards with 10/40/100Gbps or even 400Gbps
   throughput and nodes with a combined throughput of greater than
   10Tbps.  This cannot be represented in a field which is only 32-bit
   long.  A 32-bit field can only represent a max throughput of 4Gbps (2
   ^ 32 BPS).  To address this, we define another format, a wider,
   64-bit Sub-Object format.

   It is recommended that the device chooses a format based on the size
   of the value that it wants to append.  For example, If the component/
   node throughput is more less than 4Gbps, the device would append the
   "short" 32-bit Sub-Object.  When the component/node throughput
   exceeds 4Gbps, the device would append the "wide" 64-bit Sub-Object.
   This will ensure the optimal use of the formats and make the
   extension object space efficient.

   Both of these formats are interoperable and can co-exist in the same
   Extension Object. i.e. For example, if a device has two line cards,
   one with a throughput of 2Gbps and another which has a throughput of
   10Gbps, and if the device would like to append the throughput of both
   the components, as discussed above, the device will be able to choose
   a Sub-object with C-Type=6 for the line card with 2Gbps throughput
   and will also be able to choose a Sub-Object with C-Type=7 for the
   line card with 10Gbps throughput.



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7.  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.  This section
   presents 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 an IP address 198.51.100.27 executes a
   traceroute to 192.0.2.1 and the Figure 10 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
          Present Power(Node=160W,Fan=7W)
          Idle Power(Node=152W,Fan=7W,Chassis=10W)
          Throughput(53687091200bps)
          EERC(ISO 14001:2015, Energy-efficient ethernet)

     2    12 ms     9 ms     9 ms  192.0.2.9
          Present 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
          Idle Power(Node=150W,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 10: Sustainability-Metrics Infused Traceroute





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   Many use cases are possible on the basis of the ICMP extensions
   defined in this memo; it is up to the user to decide how frequently
   queries are issued, when and how these metrics are reported, or which
   policy will guide such decisions.

8.  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.

   The extensions defined in this document allows a router to append
   environmental sustainability information to multi-part ICMP messages,
   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 (AD).  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



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   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.

   High-fidelity reporting of power draw for the targeted node's memory,
   cache, hardware security module, or other sensitive component could
   allow an attacker to perform a remote side-channel attack (i.e.,
   using differential power analysis) during cryptographic operations.
   This attack would allow the adversary to extract the network node's
   secret key(s) or other sensitive data.  There are a couple of ways of
   mitigating this type of attack; exclude power metrics for components
   that process sensitive data or provide countermeasures that introduce
   noise in the reported power metrics (e.g., software that demarcates
   sensitive data which signals the processing hardware to treat this
   data with algorithmic noise).  The latter technique is an area of
   ongoing research at the time of this writing.

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

9.  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]:

    +=============+==================================+===============+
    | Class Value | Class name                       | Reference     |
    +=============+==================================+===============+
    | TBA         | Environmental Information Object | This document |
    +-------------+----------------------------------+---------------+

       Table 1: Class-num for Environmental Information Extensions

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










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     +==============+===============================+===============+
     | C-Type Value | Description                   | Reference     |
     +==============+===============================+===============+
     | 0            | Reserved                      | This document |
     +--------------+-------------------------------+---------------+
     | 1            | Node Power Draw               | This document |
     +--------------+-------------------------------+---------------+
     | 2            | Node Throughput Short         | This document |
     +--------------+-------------------------------+---------------+
     | 3            | Node Throughput Wide          | This document |
     +--------------+-------------------------------+---------------+
     | 4            | Ecolabels and Environmentally | This document |
     |              | Relevant Certification (EERC) |               |
     +--------------+-------------------------------+---------------+
     | 5            | Component-level Power Draw    | This document |
     +--------------+-------------------------------+---------------+
     | 6            | Component-level Throughput    | This document |
     |              | Short                         |               |
     +--------------+-------------------------------+---------------+
     | 7            | Component-level Throughput    | This document |
     |              | Wide                          |               |
     +--------------+-------------------------------+---------------+
     | 8-246        | Unassigned                    |               |
     +--------------+-------------------------------+---------------+
     | 247-255      | Reserved for Experimentation  | This document |
     +--------------+-------------------------------+---------------+

        Table 2: C-Types for Environmental Information Extensions

   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:
















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      +=============+==============================+===============+
      | 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 |
      +-------------+------------------------------+---------------+

                          Table 3: EERC numbers

   EERC numbers are assignable on a first-come-first-serve (FCFS) basis,
   and require a citation to the definition of the certification.

10.  Acknowledgements

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

   Thank you to Shawn Emery for providing very useful feedback and
   suggestions, and to William Hawkins III for a thorough review and
   sharing some fixes.

11.  References

11.1.  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>.

   [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>.






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   [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>.

   [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>.

11.2.  Informative References

   [EERC-EEE] "IEEE Standard for Information technology-- Local and
              metropolitan area networks-- Specific requirements-- Part
              3: CSMA/CD Access Method and Physical Layer Specifications
              Amendment 5: Media Access Control Parameters, Physical
              Layers, and Management Parameters for Energy-Efficient
              Ethernet", IEEE Std 802.3az-2010 (Amendment to IEEE Std
              802.3-2008), 27 October 2010,
              <https://standards.ieee.org/ieee/802.3az/4270/>.

   [EERC-ISO14001_2015]
              "ISO 14001:2015 Environmental management systems.
              Requirements with guidance for use", September 2015,
              <https://www.iso.org/standard/60857.html>.

   [EERC-TCO] "TCO Certified", <https://tcocertified.com/>.

   [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, 19
              January 2024, <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)", December 2022,
              <https://datatracker.ietf.org/group/eimpactws/>.

   [IAB-EIMPACTWS-Minutes]
              "Minutes for the IAB E-Impact Workshop Session 4: Next
              Steps", eimpactws Session 4, 12 December 2022,
              <https://datatracker.ietf.org/doc/minutes-interim-2022-
              eimpactws-04-202212121400/>.







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   [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, September 1981,
              <https://www.rfc-editor.org/info/rfc792>.

   [RFC4122]  Leach, P., Mealling, M., and R. Salz, "A Universally
              Unique IDentifier (UUID) URN Namespace", RFC 4122,
              DOI 10.17487/RFC4122, July 2005,
              <https://www.rfc-editor.org/info/rfc4122>.

   [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>.

   [RFC5927]  Gont, F., "ICMP Attacks against TCP", RFC 5927,
              DOI 10.17487/RFC5927, July 2010,
              <https://www.rfc-editor.org/info/rfc5927>.

   [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

   Carlos Pignataro
   North Carolina State University
   United States of America
   Email: cpignata@gmail.com, cmpignat@ncsu.edu


   Jainam Parikh
   North Carolina State University
   United States of America
   Email: jainam@parikhgroup.net, jparikh@ncsu.edu


   Ron Bonica
   Juniper Networks
   United States of America
   Email: rbonica@juniper.net




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   Michael Welzl
   University of Oslo
   Norway
   Email: michawe@ifi.uio.no















































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