Network Working Group
Internet Engineering Task Force (IETF)                        A. Bierman
Internet-Draft
Request for Comments: 8348                                     YumaWorks
Intended status:
Category: Standards Track                                   M. Bjorklund
Expires: July 26, 2018
ISSN: 2070-1721                                           Tail-f Systems
                                                                 J. Dong
                                                     Huawei Technologies
                                                            D. Romascanu
                                                        January 22,
                                                              March 2018

               A YANG Data Model for Hardware Management
                      draft-ietf-netmod-entity-08

Abstract

   This document defines a YANG data model for the management of
   hardware on a single server.

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 an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list  It represents the consensus of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid the IETF community.  It has
   received public review and has been approved for a maximum publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of six months this document, any errata,
   and how to provide feedback on it may be updated, replaced, or obsoleted by other documents obtained 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 July 26, 2018.
   https://www.rfc-editor.org/info/rfc8348.

Copyright Notice

   Copyright (c) 2018 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
   (http://trustee.ietf.org/license-info)
   (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 Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2 ....................................................3
      1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . .   2 ................................................3
      1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   3 ..............................................3
   2. Objectives  . . . . . . . . . . . . . . . . . . . . . . . . .   3 ......................................................4
   3. Hardware Data Model . . . . . . . . . . . . . . . . . . . . .   3 .............................................4
      3.1. The Components Lists  . . . . . . . . . . . . . . . . . .   5 .......................................5
   4. Relationship to ENTITY-MIB  . . . . . . . . . . . . . . . . .   5 ......................................6
   5. Relationship to ENTITY-SENSOR-MIB . . . . . . . . . . . . . .   6 ...............................8
   6. Relationship to ENTITY-STATE-MIB  . . . . . . . . . . . . . .   7 ................................8
   7. Hardware YANG Modules ...........................................9
      7.1. "ietf-hardware" Module  . . . . . . . . . . . . . . . . . . . .   7 .....................................9
      7.2. "iana-hardware" Module ....................................34
   8. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  35 ............................................38
      8.1. URI Registrations . . . . . . . . . . . . . . . . . . . .  35 .........................................38
      8.2. YANG Module Registrations . . . . . . . . . . . . . . . .  36 .................................39
   9. Security Considerations . . . . . . . . . . . . . . . . . . .  36 ........................................39
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  37
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  37
     11.1. ....................................................40
      10.1. Normative References . . . . . . . . . . . . . . . . . .  37
     11.2. .....................................40
      10.2. Informative References . . . . . . . . . . . . . . . . .  39 ...................................41
   Appendix A.  Hardware State Data Model  . . . . . . . . . . . . .  39 ............................42
     A.1.  Hardware State YANG Module  . . . . . . . . . . . . . . .  40 ................................43
   Acknowledgments ...................................................60
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  55 ................................................60

1.  Introduction

   This document defines a YANG [RFC7950] data model [RFC7950] for the management
   of hardware on a single server.

   The data model includes configuration and system state (status
   information and counters for the collection of statistics).

   The data model in this document is designed to be compliant with the
   Network Management Datastore Architecture (NMDA)
   [I-D.ietf-netmod-revised-datastores]. [RFC8342].  For
   implementations that do not yet support NMDA, a temporary module with
   system state data only is defined in Appendix A.

1.1.  Terminology

   The keywords 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, 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   The following terms are defined in
   [I-D.ietf-netmod-revised-datastores] [RFC8342] and are not redefined
   here:

   o  client

   o  server

   o  configuration

   o  system state

   o  operational state

   o  intended configuration

1.2.  Tree Diagrams

   Tree diagrams used in this document follow the notation defined in
   [I-D.ietf-netmod-yang-tree-diagrams].
   [RFC8340].

2.  Objectives

   This section describes some of the design objectives for the hardware
   data model.

   o  There are  The hardware data model needs to support many common properties
      used to identify hardware
      components, which need to be supported in the hardware data model. components.

   o  There are many important  Important information and states about the
      components, which needs hardware components need to
      be collected from the devices which that support the hardware data model.

   o  The hardware data model should be suitable for new implementations
      to use as is.

   o  The hardware data model defined in this document can be
      implemented on a system that also implements ENTITY-MIB, thus ENTITY-MIB; thus, the
      mapping between the hardware data model and ENTITY-MIB should be
      clear.

   o  The data model should support pre-provisioning of hardware
      components.

3.  Hardware Data Model

   This document defines the YANG module "ietf-hardware", which has the
   following structure:

   module: ietf-hardware
     +--rw hardware
        +--ro last-change?   yang:date-and-time
        +--rw component* [name]
           +--rw name              string
           +--rw class             identityref
           +--ro physical-index?   int32 {entity-mib}?
           +--ro description?      string
           +--rw parent?           -> ../../component/name
           +--rw parent-rel-pos?   int32
           +--ro contains-child*   -> ../../component/name
           +--ro hardware-rev?     string
           +--ro firmware-rev?     string
           +--ro software-rev?     string
           +--ro serial-num?       string
           +--ro mfg-name?         string
           +--ro model-name?       string
           +--rw alias?            string
           +--rw asset-id?         string
           +--ro is-fru?           boolean
           +--ro mfg-date?         yang:date-and-time
           +--rw uri*              inet:uri
           +--ro uuid?             yang:uuid
           +--rw state {hardware-state}?
           |  +--ro state-last-changed?   yang:date-and-time
           |  +--rw admin-state?          admin-state
           |  +--ro oper-state?           oper-state
           |  +--ro usage-state?          usage-state
           |  +--ro alarm-state?          alarm-state
           |  +--ro standby-state?        standby-state
           +--ro sensor-data {hardware-sensor}?
              +--ro value?               sensor-value
              +--ro value-type?          sensor-value-type
              +--ro value-scale?         sensor-value-scale
              +--ro value-precision?     sensor-value-precision
              +--ro oper-status?         sensor-status
              +--ro units-display?       string
              +--ro value-timestamp?     yang:date-and-time
              +--ro value-update-rate?   uint32

     notifications:
       +---n hardware-state-change
       +---n hardware-state-oper-enabled {hardware-state}?
       |  +--ro name?          -> /hardware/component/name
       |  +--ro admin-state?   -> /hardware/component/state/admin-state
       |  +--ro alarm-state?   -> /hardware/component/state/alarm-state
       +---n hardware-state-oper-disabled {hardware-state}?
          +--ro name?          -> /hardware/component/name
          +--ro admin-state?   -> /hardware/component/state/admin-state
          +--ro alarm-state?   -> /hardware/component/state/alarm-state

3.1.  The Components Lists

   The data model for hardware presented in this document uses a flat
   list of components.  Each component in the list is identified by its
   name.  Furthermore, each component has a mandatory "class" leaf.

   The "iana-hardware" module defines YANG identities for the hardware
   types in the IANA-maintained "IANA-ENTITY-MIB" registry.

   The "class" leaf is a YANG identity that describes the type of the
   hardware.  Vendors are encouraged to either directly use one of the
   common IANA-defined identities, identities or derive a more specific identity
   from one of them.

4.  Relationship to ENTITY-MIB

   If the device implements the ENTITY-MIB [RFC6933], each entry in the
   "/hardware/component" list in the operational state is mapped to one
   EntPhysicalEntry.  Objects that are writable in the MIB are mapped to
   "config true" nodes in the "/hardware/component" list, except
   "entPhysicalSerialNum"
   entPhysicalSerialNum, which is writable in the MIB, MIB but "config false"
   in the YANG module.

   The "physical-index" leaf MUST contain the value of the corresponding
   entPhysicalEntry's entPhysicalIndex.

   The "class" leaf is mapped to both entPhysicalClass and
   entPhysicalVendorType.  If the value of the "class" leaf is an
   identity that is either is derived from or is one of the identities in
   the "iana-hardware" module, then entPhysicalClass contains the
   corresponding IANAPhysicalClass enumeration value.  Otherwise,
   entPhysicalClass contains the IANAPhysicalClass value "other(1)".
   Vendors are encouraged to define an identity (derived from an
   identity in "iana-hardware" if possible) for each enterprise-specific
   registration identifier used for entPhysicalVendorType, entPhysicalVendorType and use that
   identity for the "class" leaf.

   The following tables list table lists the YANG data nodes with corresponding
   objects in the ENTITY-MIB.

   +--------------------------------+----------------------------------+
   | YANG data node in              | ENTITY-MIB object                |
   | /hardware/component            |                                  |
   +--------------------------------+----------------------------------+
   | name                           | entPhysicalName                  |
   | class                          | entPhysicalClass                 |
   |                                | entPhysicalVendorType            |
   | physical-index                 | entPhysicalIndex                 |
   | description                    | entPhysicalDescr                 |
   | parent                         | entPhysicalContainedIn           |
   | parent-rel-pos                 | entPhysicalParentRelPos          |
   | contains-child                 | entPhysicalChildIndex            |
   | hardware-rev                   | entPhysicalHardwareRev           |
   | firmware-rev                   | entPhysicalFirmwareRev           |
   | software-rev                   | entPhysicalSoftwareRev           |
   | serial-num                     | entPhysicalSerialNum             |
   | mfg-name                       | entPhysicalMfgName               |
   | model-name                     | entPhysicalModelName             |
   | alias                          | entPhysicalAlias                 |
   | asset-id                       | entPhysicalAssetID               |
   | is-fru                         | entPhysicalIsFRU                 |
   | mfg-date                       | entPhysicalMfgDate               |
   | uri                            | entPhysicalUris                  |
   | uuid                           | entPhysicalUUID                  |
   +--------------------------------+----------------------------------+

              YANG Data Nodes and Related ENTITY-MIB Objects

5.  Relationship to ENTITY-SENSOR-MIB

   If the device implements the ENTITY-SENSOR-MIB [RFC3433], each entry
   in the "/hardware/component" list where the container "sensor-data"
   exists is mapped to one EntPhySensorEntry.

   The following table lists the YANG data nodes with corresponding
   objects in the ENTITY-SENSOR-MIB.

   +-------------------------------------+-----------------------------+
   | YANG data node in                   | ENTITY-SENSOR-MIB object    |
   | /hardware/component/sensor-data     |                             |
   +-------------------------------------+-----------------------------+
   | value                               | entPhySensorValue           |
   | value-type                          | entPhySensorType            |
   | value-scale                         | entPhySensorScale           |
   | value-precision                     | entPhySensorPrecision       |
   | oper-status                         | entPhySensorOperStatus      |
   | units-display                       | entPhySensorUnitsDisplay    |
   | value-timestamp                     | entPhySensorValueTimeStamp  |
   | value-update-rate                   | entPhySensorValueUpdateRate |
   +-------------------------------------+-----------------------------+

           YANG Data Nodes and Related ENTITY-SENSOR-MIB Objects

6.  Relationship to ENTITY-STATE-MIB

   If the device implements the ENTITY-STATE-MIB [RFC4268], each entry
   in the "/hardware/component" list where the container "state" exists
   is mapped to one EntStateEntry.

   The following table lists the YANG data nodes with corresponding
   objects in the ENTITY-STATE-MIB.

   +------------------------------------------+------------------------+
   | YANG data node in                        | ENTITY-STATE-MIB       |
   | /hardware/component/state                | object                 |
   +------------------------------------------+------------------------+
   | state-last-changed                       | entStateLastChanged    |
   | admin-state                              | entStateAdmin          |
   | oper-state                               | entStateOper           |
   | usage-state                              | entStateUsage          |
   | alarm-state                              | entStateAlarm          |
   | standby-state                            | entStateStandby        |
   +------------------------------------------+------------------------+

           YANG Data Nodes and Related ENTITY-SENSOR-MIB Objects

7.  Hardware YANG Modules

7.1.  "ietf-hardware" Module

   This YANG module imports typedefs from [RFC6991].

   <CODE BEGINS> file "ietf-hardware@2018-01-15.yang" "ietf-hardware@2018-03-13.yang"

  module ietf-hardware {
    yang-version 1.1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-hardware";
    prefix hw;

    import ietf-inet-types {
      prefix inet;
    }
    import ietf-yang-types {
      prefix yang;
    }
    import iana-hardware {
      prefix ianahw;
    }

    organization
      "IETF NETMOD (Network Modeling) Working Group";

    contact
      "WG Web:   <http://tools.ietf.org/wg/netmod/>   <https://datatracker.ietf.org/wg/netmod/>
       WG List:  <mailto:netmod@ietf.org>

       Editor:   Andy Bierman
                 <mailto:andy@yumaworks.com>

       Editor:   Martin Bjorklund
                 <mailto:mbj@tail-f.com>

       Editor:   Jie Dong
                 <mailto:jie.dong@huawei.com>

       Editor:   Dan Romascanu
                 <mailto:dromasca@gmail.com>";

     // RFC Ed.: replace XXXX and YYYY with actual RFC numbers and
     // remove this note.

    description
      "This module contains a collection of YANG definitions for
       managing hardware.

       This data model is designed for the Network Management Datastore
       Architecture (NMDA) defined in RFC YYYY. 8342.

       Copyright (c) 2018 IETF Trust and the persons identified as
       authors of the code.  All rights reserved.

       Redistribution and use in source and binary forms, with or
       without modification, is permitted pursuant to, and subject
       to the license terms contained in, the Simplified BSD License
       set forth in Section 4.c of the IETF Trust's Legal Provisions
       Relating to IETF Documents
        (http://trustee.ietf.org/license-info).
       (https://trustee.ietf.org/license-info).

       This version of this YANG module is part of RFC XXXX; 8348; see
       the RFC itself for full legal notices.";
     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.

    revision 2018-01-15 2018-03-13 {
      description
        "Initial revision.";
      reference
        "RFC XXXX: 8348: A YANG Data Model for Hardware Management";
    }

    /*
     * Features
     */

    feature entity-mib {
      description
        "This feature indicates that the device implements
         the ENTITY-MIB.";
      reference
        "RFC 6933: Entity MIB (Version 4)";
    }

    feature hardware-state {
      description
        "Indicates the that ENTITY-STATE-MIB objects are supported";
      reference
        "RFC 4268: Entity State MIB";
    }

    feature hardware-sensor {
      description
        "Indicates the that ENTITY-SENSOR-MIB objects are supported";
      reference
        "RFC 3433: Entity Sensor MIB"; Management Information Base";
    }

    /*
     * Typedefs
     */

    typedef admin-state {
      type enumeration {
        enum unknown {
          value 1;
          description
            "The resource is unable to report administrative state.";
        }
        enum locked {
          value 2;
          description
            "The resource is administratively prohibited from use.";
        }
        enum shutting-down {
          value 3;
          description
            "The resource usage is administratively limited to current
             instances of use.";
        }
        enum unlocked {
          value 4;
          description
            "The resource is not administratively prohibited from
             use.";
        }
      }
      description
        "Represents the various possible administrative states.";
      reference
        "RFC 4268: Entity State MIB - EntityAdminState";
    }

    typedef oper-state {
      type enumeration {
        enum unknown {
          value 1;
          description
            "The resource is unable to report its operational state.";
        }
        enum disabled {
          value 2;
          description
            "The resource is totally inoperable.";
        }
        enum enabled {
          value 3;
          description
            "The resource is partially or fully operable.";
        }
        enum testing {
          value 4;
          description
            "The resource is currently being tested and cannot
             therefore report whether or not it is operational or not."; operational.";
        }
      }
      description
        "Represents the possible values of operational states.";
      reference
        "RFC 4268: Entity State MIB - EntityOperState";
    }

    typedef usage-state {
      type enumeration {
        enum unknown {
          value 1;
          description
            "The resource is unable to report usage state.";
        }
        enum idle {
          value 2;
          description
            "The resource is servicing no users.";
        }
        enum active {
          value 3;
          description
            "The resource is currently in use use, and it has sufficient
             spare capacity to provide for additional users.";
        }
        enum busy {
          value 4;
          description
            "The resource is currently in use, but it currently has no
             spare capacity to provide for additional users.";
        }
      }
      description
        "Represents the possible values of usage states.";
      reference
        "RFC 4268, 4268: Entity State MIB -  EntityUsageState";
    }

    typedef alarm-state {
      type bits {
        bit unknown {
          position 0;
          description
            "The resource is unable to report alarm state.";
        }
        bit under-repair {
          position 1;
          description
            "The resource is currently being repaired, which, depending
             on the implementation, may make the other values in this
             bit string not meaningful.";
        }
        bit critical {
          position 2;
          description
            "One or more critical alarms are active against the
             resource.";
        }
        bit major {
          position 3;
          description
            "One or more major alarms are active against the
             resource.";
        }
        bit minor {
          position 4;
          description
            "One or more minor alarms are active against the
             resource.";
        }
        bit warning {
          position 5;
          description
            "One or more warning alarms are active against the
             resource.";
        }
        bit indeterminate {
          position 6;
          description
            "One or more alarms of whose perceived severity cannot be
             determined are active against this resource.";
        }
      }
      description
        "Represents the possible values of alarm states.  An alarm is a
         persistent indication of an error or warning condition.

         When no bits of this attribute are set, then no active alarms
         are known against this component and it is not under repair.";
      reference
        "RFC 4268: Entity State MIB - EntityAlarmStatus";
    }

    typedef standby-state {
      type enumeration {
        enum unknown {
          value 1;
          description
            "The resource is unable to report standby state.";
        }
        enum hot-standby {
          value 2;
          description
            "The resource is not providing service, but it will be
             immediately able to take over the role of the resource to
             be backed up, without the need for initialization
             activity, and will contain the same information as the
             resource to be backed up.";
        }
        enum cold-standby {
          value 3;
          description
            "The resource is to back up another resource, but it will
             not be immediately able to take over the role of a
             resource to be backed up, up and will require some
             initialization activity.";
        }
        enum providing-service {
          value 4;
          description
            "The resource is providing service.";
        }
      }
      description
        "Represents the possible values of standby states.";
      reference
        "RFC 4268: Entity State MIB - EntityStandbyStatus";
    }

    typedef sensor-value-type {
      type enumeration {
        enum other {
          value 1;
          description
            "A measure other than those listed below.";
        }
        enum unknown {
          value 2;
          description
            "An unknown measurement, measurement or arbitrary, relative numbers";
        }
        enum volts-AC {
          value 3;
          description
            "A measure of electric potential (alternating current).";
        }
        enum volts-DC {
          value 4;
          description
            "A measure of electric potential (direct current).";
        }
        enum amperes {
          value 5;
          description
            "A measure of electric current.";
        }
        enum watts {
          value 6;
          description
            "A measure of power.";
        }
        enum hertz {
          value 7;
          description
            "A measure of frequency.";
        }
        enum celsius {
          value 8;
          description
            "A measure of temperature.";
        }
        enum percent-RH {
          value 9;
          description
            "A measure of percent relative humidity.";
        }
        enum rpm {
          value 10;
          description
            "A measure of shaft revolutions per minute.";
        }
        enum cmm {
          value 11;
          description
            "A measure of cubic meters per minute (airflow).";
        }
        enum truth-value {
          value 12;
          description
            "Value is one of 1 (true) or 2 (false)";
        }
      }
      description
        "A node using this data type represents the sensor measurement
         data type associated with a physical sensor value.  The actual
         data units are determined by examining a node of this type
         together with the associated sensor-value-scale node.

         A node of this type SHOULD be defined together with nodes of
         type sensor-value-scale and type sensor-value-precision.
         These three types are used to identify the semantics of a node
         of type sensor-value.";
      reference
        "RFC 3433: Entity Sensor Management Information Base -
                   EntitySensorDataType";
    }

    typedef sensor-value-scale {
      type enumeration {
        enum yocto {
          value 1;
          description
            "Data scaling factor of 10^-24.";
        }
        enum zepto {
          value 2;
          description
            "Data scaling factor of 10^-21.";
        }
        enum atto {
          value 3;
          description
            "Data scaling factor of 10^-18.";
        }
        enum femto {
          value 4;
          description
            "Data scaling factor of 10^-15.";
        }
        enum pico {
          value 5;
          description
            "Data scaling factor of 10^-12.";
        }
        enum nano {
          value 6;
          description
            "Data scaling factor of 10^-9.";
        }
        enum micro {
          value 7;
          description
            "Data scaling factor of 10^-6.";
        }
        enum milli {
          value 8;
          description
            "Data scaling factor of 10^-3.";
        }
        enum units {
          value 9;
          description
            "Data scaling factor of 10^0.";
        }
        enum kilo {
          value 10;
          description
            "Data scaling factor of 10^3.";
        }
        enum mega {
          value 11;
          description
            "Data scaling factor of 10^6.";
        }
        enum giga {
          value 12;
          description
            "Data scaling factor of 10^9.";
        }
        enum tera {
          value 13;
          description
            "Data scaling factor of 10^12.";
        }
        enum peta {
          value 14;
          description
            "Data scaling factor of 10^15.";
        }
        enum exa {
          value 15;
          description
            "Data scaling factor of 10^18.";
        }
        enum zetta {
          value 16;
          description
            "Data scaling factor of 10^21.";
        }
        enum yotta {
          value 17;
          description
            "Data scaling factor of 10^24.";
        }
      }
      description
        "A node using this data type represents a data scaling factor,
         represented with an International System of Units (SI) prefix.
         The actual data units are determined by examining a node of
         this type together with the associated sensor-value-type.

         A node of this type SHOULD be defined together with nodes of
         type sensor-value-type and type sensor-value-precision.
         Together, associated nodes of these three types are used to
         identify the semantics of a node of type sensor-value.";
      reference
        "RFC 3433: Entity Sensor Management Information Base -
                   EntitySensorDataScale";
    }

    typedef sensor-value-precision {
      type int8 {
        range "-8 .. 9";
      }
      description
        "A node using this data type represents a sensor value
         precision range.

         A node of this type SHOULD be defined together with nodes of
         type sensor-value-type and type sensor-value-scale.  Together,
         associated nodes of these three types are used to identify the
         semantics of a node of type sensor-value.

         If a node of this type contains a value in the range 1 to 9,
         it represents the number of decimal places in the fractional
         part of an associated sensor-value fixed- point fixed-point number.

         If a node of this type contains a value in the range -8 to -1,
         it represents the number of accurate digits in the associated
         sensor-value fixed-point number.

         The value zero indicates the associated sensor-value node is
         not a fixed-point number.

         Server implementers must choose a value for the associated
         sensor-value-precision node so that the precision and accuracy
         of the associated sensor-value node is correctly indicated.

         For example, a component representing a temperature sensor
         that can measure 0 degrees to 100 degrees C in 0.1 degree
         increments, +/- 0.05 degrees, would have a
         sensor-value-precision value of '1', a sensor-value-scale
         value of 'units', and a sensor-value ranging from '0' to
         '1000'.  The sensor-value would be interpreted as
         'degrees C * 10'.";
      reference
        "RFC 3433: Entity Sensor Management Information Base -
                   EntitySensorPrecision";
    }

    typedef sensor-value {
      type int32 {
        range "-1000000000 .. 1000000000";
      }
      description
       "A node using this data type represents a sensor value.

        A node of this type SHOULD be defined together with nodes of
        type sensor-value-type, type sensor-value-scale, and
        type sensor-value-precision.  Together, associated nodes of
        those three types are used to identify the semantics of a node
        of this data type.

        The semantics of a node using this data type are determined by
        the value of the associated sensor-value-type node.

        If the associated sensor-value-type node is equal to 'voltsAC',
        'voltsDC', 'amperes', 'watts', 'hertz', 'celsius', or 'cmm',
        then a node of this type MUST contain a fixed point fixed-point number
        ranging from -999,999,999 to +999,999,999.  The value
        -1000000000 indicates an underflow error.  The value
        +1000000000 indicates an overflow error.  The
        sensor-value-precision indicates how many fractional digits
        are represented in the associated sensor-value node.

        If the associated sensor-value-type node is equal to
        'percentRH', then a node of this type MUST contain a number
        ranging from 0 to 100.

        If the associated sensor-value-type node is equal to 'rpm',
        then a node of this type MUST contain a number ranging from
        -999,999,999 to +999,999,999.

        If the associated sensor-value-type node is equal to
        'truth-value', then a node of this type MUST contain either the
        value 1 (true) or the value 2 (false)'. (false).

        If the associated sensor-value-type node is equal to 'other' or
         unknown',
        'unknown', then a node of this type MUST contain a number
        ranging from -1000000000 to 1000000000.";
      reference
        "RFC 3433: Entity Sensor Management Information Base -
                   EntitySensorValue";
    }

    typedef sensor-status {
      type enumeration {
        enum ok {
          value 1;
          description
            "Indicates that the server can obtain the sensor value.";
        }
        enum unavailable {
          value 2;
          description
            "Indicates that the server presently cannot obtain the
             sensor value.";
        }
        enum nonoperational {
          value 3;
          description
            "Indicates that the server believes the sensor is broken.
             The sensor could have a hard failure (disconnected wire), wire)
             or a soft failure such as out-of-range, jittery, or wildly
             fluctuating readings.";
        }
      }
      description
        "A node using this data type represents the operational status
         of a physical sensor.";
      reference
        "RFC 3433: Entity Sensor Management Information Base -
                   EntitySensorStatus";
    }

    /*
     * Data nodes
     */

    container hardware {
      description
        "Data nodes representing components.

         If the server supports configuration of hardware components,
         then this data model is instantiated in the configuration
         datastores supported by the server.  The leaf-list 'datastore'
         for the module 'ietf-hardware' in the YANG library provides
         this information.";

      leaf last-change {
        type yang:date-and-time;
        config false;
        description
          "The time the '/hardware/component' list changed in the
           operational state.";
      }

      list component {
        key name;
        description
          "List of components.

           When the server detects a new hardware component, it
           initializes a list entry in the operational state.

           If the server does not support configuration of hardware
           components, list entries in the operational state are
           initialized with values for all nodes as detected by the
           implementation.

           Otherwise, the following this procedure is followed:

             1. If there is an entry in the /hardware/component '/hardware/component' list
                in the intended configuration with values for the nodes
                'class', 'parent', and 'parent-rel-pos' that are equal
                to the detected values, then the list entry in the
                operational state is initialized with the configured
                values, including the 'name'.

             2. Otherwise (i.e., there is no matching configuration
                entry), the list entry in the operational state is
                initialized with values for all nodes as detected by
                the implementation.

           If the /hardware/component '/hardware/component' list in the intended
           configuration is modified, then the system MUST behave as if
           it re-initializes itself, itself and follow the procedure in (1).";
        reference
          "RFC 6933: Entity MIB (Version 4) - entPhysicalEntry";

        leaf name {
          type string;
          description
            "The name assigned to this component.

             This name is not required to be the same as
             entPhysicalName.";
        }

        leaf class {
          type identityref {
            base ianahw:hardware-class;
          }
          mandatory true;
          description
            "An indication of the general hardware type of the
             component.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalClass";
        }

        leaf physical-index {
          if-feature entity-mib;
          type int32 {
            range "1..2147483647";
          }
          config false;
          description
            "The entPhysicalIndex for the entPhysicalEntry represented
             by this list entry.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalIndex";
        }

        leaf description {
          type string;
          config false;
          description
            "A textual description of the component.  This node should
             contain a string that identifies the manufacturer's name
             for the component and should be set to a distinct value
             for each version or model of the component.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalDescr";
        }

        leaf parent {
          type leafref {
            path "../../component/name";
            require-instance false;
          }
          description
            "The name of the component that physically contains this
             component.

             If this leaf is not instantiated, it indicates that this
             component is not contained in any other component.

             In the event that a physical component is contained by
             more than one physical component (e.g., double-wide
             modules), this node contains the name of one of these
             components.  An implementation MUST use the same name
             every time this node is instantiated.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalContainedIn";
        }

        leaf parent-rel-pos {
          type int32 {
            range "0 .. 2147483647";
          }
          description
            "An indication of the relative position of this child
             component among all its sibling components.  Sibling
             components are defined as components that:

               o Share share the same value of the 'parent' node; node and

               o Share share a common base identity for the 'class' node.

             Note that the last rule gives implementations flexibility
             in how components are numbered.  For example, some
             implementations might have a single number series for all
             components derived from 'ianahw:port', while some others
             might have different number series for different
             components with identities derived from 'ianahw:port' (for
             example, one for RJ45 registered jack 45 (RJ45) and one for SFP).";
             small form-factor pluggable (SFP)).";

          reference
            "RFC 6933: Entity MIB (Version 4) -
                       entPhysicalParentRelPos";
        }

        leaf-list contains-child {
          type leafref {
            path "../../component/name";
          }
          config false;
          description
            "The name of the contained component.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalChildIndex";
        }

        leaf hardware-rev {
          type string;
          config false;
          description
            "The vendor-specific hardware revision string for the
             component.  The preferred value is the hardware revision
             identifier actually printed on the component itself (if
             present).";
          reference
            "RFC 6933: Entity MIB (Version 4) -
                       entPhysicalHardwareRev";
        }

        leaf firmware-rev {
          type string;
          config false;
          description
            "The vendor-specific firmware revision string for the
             component.";
          reference
            "RFC 6933: Entity MIB (Version 4) -
                       entPhysicalFirmwareRev";
        }

        leaf software-rev {
          type string;
          config false;
          description
            "The vendor-specific software revision string for the
             component.";
          reference
            "RFC 6933: Entity MIB (Version 4) -
                       entPhysicalSoftwareRev";
        }

        leaf serial-num {
          type string;
          config false;
          description
            "The vendor-specific serial number string for the
             component.  The preferred value is the serial number
             string actually printed on the component itself (if
             present).";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalSerialNum";
        }

        leaf mfg-name {
          type string;
          config false;
          description
            "The name of the manufacturer of this physical component.
             The preferred value is the manufacturer name string
             actually printed on the component itself (if present).

             Note that comparisons between instances of the model-name,
              firmware-rev, software-rev,
             'model-name', 'firmware-rev', 'software-rev', and the serial-num
             'serial-num' nodes are only meaningful amongst component components
             with the same value of
              mfg-name. 'mfg-name'.

             If the manufacturer name string associated with the
             physical component is unknown to the server, then this
             node is not instantiated.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalMfgName";
        }

        leaf model-name {
          type string;
          config false;
          description
            "The vendor-specific model name identifier string
             associated with this physical component.  The preferred
             value is the customer-visible part number, which may be
             printed on the component itself.

             If the model name string associated with the physical
             component is unknown to the server, then this node is not
             instantiated.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalModelName";
        }

        leaf alias {
          type string;
          description
            "An 'alias' name for the component, as specified by a
             network manager, and that provides a non-volatile 'handle' for
             the component.

             If no configured value exists, the server MAY set the
             value of this node to a locally unique value in the
             operational state.

             A server implementation MAY map this leaf to the
             entPhysicalAlias MIB object.  Such an implementation needs
             to use some mechanism to handle the differences in size
             and characters allowed between this leaf and
             entPhysicalAlias.  The definition of such a mechanism is
             outside the scope of this document.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalAlias";
        }

        leaf asset-id {
          type string;
          description
            "This node is a user-assigned asset tracking identifier for
             the component.

             A server implementation MAY map this leaf to the
             entPhysicalAssetID MIB object.  Such an implementation
             needs to use some mechanism to handle the differences in
             size and characters allowed between this leaf and
             entPhysicalAssetID.  The definition of such a mechanism is
             outside the scope of this document.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalAssetID";
        }

        leaf is-fru {
          type boolean;
          config false;
          description
            "This node indicates whether or not this component is
             considered a 'field replaceable 'field-replaceable unit' by the vendor.  If
             this node contains the value 'true', then this component
             identifies a field replaceable field-replaceable unit.  For all components
             that are permanently contained within a field replaceable field-replaceable
             unit, the value 'false' should be returned for this
             node.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalIsFRU";
        }

        leaf mfg-date {
          type yang:date-and-time;
          config false;
          description
            "The date of manufacturing of the managed component.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalMfgDate";
        }

        leaf-list uri {
          type inet:uri;
          description
            "This node contains identification information about the
             component.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalUris";
        }

        leaf uuid {
          type yang:uuid;
          config false;
          description
            "A Universally Unique Identifier of the component.";
          reference
            "RFC 6933: Entity MIB (Version 4) - entPhysicalUUID";
        }

        container state {
          if-feature hardware-state;
          description
            "State-related nodes";
          reference
            "RFC 4268: Entity State MIB";

          leaf state-last-changed {
            type yang:date-and-time;
            config false;
            description
              "The date and time when the value of any of the
               admin-state, oper-state, usage-state, alarm-state, or
               standby-state changed for this component.

               If there has been no change since the last
               re-initialization of the local system, this node
               contains the date and time of local system
               initialization.  If there has been no change since the
               component was added to the local system, this node
               contains the date and time of the insertion.";
            reference
              "RFC 4268: Entity State MIB - entStateLastChanged";
          }

          leaf admin-state {
            type admin-state;
            description
              "The administrative state for this component.

               This node refers to a component's administrative
               permission to service both other components within its
               containment hierarchy as well other users of its
               services defined by means outside the scope of this
               module.

               Some components exhibit only a subset of the remaining
               administrative state values.  Some components cannot be
                locked, and hence
               locked; hence, this node exhibits only the 'unlocked'
               state.  Other components cannot be shutdown gracefully,
                and hence shut down gracefully;
               hence, this node does not exhibit the 'shutting-down'
               state.";
            reference
              "RFC 4268: Entity State MIB - entStateAdmin";
          }

          leaf oper-state {
            type oper-state;
            config false;
            description
              "The operational state for this component.

               Note that this node does not follow the administrative
               state.  An administrative state of down 'down' does not
               predict an operational state of disabled. 'disabled'.

               Note that some implementations may not be able to
               accurately report oper-state while the admin-state node
               has a value other than 'unlocked'.  In these cases, this
               node MUST have a value of 'unknown'.";
            reference
              "RFC 4268: Entity State MIB - entStateOper";
          }

          leaf usage-state {
            type usage-state;
            config false;
            description
              "The usage state for this component.

               This node refers to a component's ability to service
               more components in a containment hierarchy.

               Some components will exhibit only a subset of the usage
               state values.  Components that are unable to ever
               service any components within a containment hierarchy
               will always have a usage state of 'busy'.  Some
                components 'busy'.  In some
               cases, a component will only ever be able to support only one
               other component within its containment hierarchy and
               will therefore only exhibit values of 'idle' and
               'busy'.";
            reference
              "RFC 4268, 4268: Entity State MIB - entStateUsage";
          }

          leaf alarm-state {
            type alarm-state;
            config false;
            description
              "The alarm state for this component.  It does not
               include the alarms raised on child components within its
               containment hierarchy.";
            reference
              "RFC 4268: Entity State MIB - entStateAlarm";
          }

          leaf standby-state {
            type standby-state;
            config false;
            description
              "The standby state for this component.

               Some components will exhibit only a subset of the
               remaining standby state values.  If this component
               cannot operate in a standby role, the value of this node
               will always be 'providing-service'.";
            reference
              "RFC 4268: Entity State MIB - entStateStandby";
          }
        }

        container sensor-data {
          when 'derived-from-or-self(../class,
                                     "ianahw:sensor")' {
            description
              "Sensor data nodes present for any component of type
               'sensor'";
          }
          if-feature hardware-sensor;
          config false;

          description
            "Sensor-related nodes.";
          reference
            "RFC 3433: Entity Sensor MIB"; Management Information Base";

          leaf value {
            type sensor-value;
            description
              "The most recent measurement obtained by the server
               for this sensor.

               A client that periodically fetches this node should also
               fetch the nodes 'value-type', 'value-scale', and
               'value-precision', since they may change when the value
               is changed.";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorValue";
          }

          leaf value-type {
            type sensor-value-type;
            description
              "The type of data units associated with the
               sensor value";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorType";
          }
          leaf value-scale {
            type sensor-value-scale;
            description
              "The (power of 10) scaling factor associated
               with the sensor value";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorScale";
          }

          leaf value-precision {
            type sensor-value-precision;
            description
              "The number of decimal places of precision
               associated with the sensor value";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorPrecision";
          }

          leaf oper-status {
            type sensor-status;
            description
              "The operational status of the sensor.";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorOperStatus";
          }

          leaf units-display {
            type string;
            description
              "A textual description of the data units that should be
               used in the display of the sensor value.";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorUnitsDisplay";
          }

          leaf value-timestamp {
            type yang:date-and-time;
            description
              "The time the status and/or value of this sensor was last
               obtained by the server.";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorValueTimeStamp";
          }
          leaf value-update-rate {
            type uint32;
            units "milliseconds";
            description
              "An indication of the frequency that the server updates
               the associated 'value' node, representing represented in
               milliseconds.  The value zero indicates:

                - the sensor value is updated on demand (e.g.,
                  when polled by the server for a get-request),

                - the sensor value is updated when the sensor
                  value changes (event-driven), or

                - the server does not know the update rate.";
            reference
              "RFC 3433: Entity Sensor Management Information Base -
                         entPhySensorValueUpdateRate";
          }
        }
      }
    }

    /*
     * Notifications
     */

    notification hardware-state-change {
      description
        "A hardware-state-change notification is generated when the
         value of /hardware/last-change changes in the operational
         state.";
      reference
        "RFC 6933, 6933: Entity MIB (Version 4) - entConfigChange";
    }

    notification hardware-state-oper-enabled {
      if-feature hardware-state;
      description
        "A hardware-state-oper-enabled notification signifies that a
         component has transitioned into the 'enabled' state.";

      leaf name {
        type leafref {
          path "/hardware/component/name";
        }
        description
          "The name of the component that has transitioned into the
           'enabled' state.";
      }
      leaf admin-state {
        type leafref {
          path "/hardware/component/state/admin-state";
        }
        description
          "The administrative state for the component.";
      }
      leaf alarm-state {
        type leafref {
          path "/hardware/component/state/alarm-state";
        }
        description
          "The alarm state for the component.";
      }
      reference
        "RFC 4268, 4268: Entity State MIB - entStateOperEnabled";
    }

    notification hardware-state-oper-disabled {
      if-feature hardware-state;
      description
        "A hardware-state-oper-disabled notification signifies that a
         component has transitioned into the 'disabled' state.";

      leaf name {
        type leafref {
          path "/hardware/component/name";
        }
        description
          "The name of the component that has transitioned into the
           'disabled' state.";
      }
      leaf admin-state {
        type leafref {
          path "/hardware/component/state/admin-state";
        }
        description
          "The administrative state for the component.";
      }
      leaf alarm-state {
        type leafref {
          path "/hardware/component/state/alarm-state";
        }
        description
          "The alarm state for the component.";
      }
      reference
        "RFC 4268, 4268: Entity State MIB - entStateOperDisabled";
    }

  }

   <CODE ENDS>

7.2.  "iana-hardware" Module

   <CODE BEGINS> file "iana-hardware@2018-01-15.yang" "iana-hardware@2018-03-13.yang"

   module iana-hardware {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-hardware";
     prefix ianahw;

     organization "IANA";
     contact
       "        Internet Assigned Numbers Authority

        Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA  90094-2536
                United States of America

        Tel:    +1 310 301 5800
        E-Mail: iana@iana.org>";
     // RFC Ed.: replace XXXX with actual RFC number and remove this
     // note.

     description
       "IANA defined
       "IANA-defined identities for hardware class.

        The latest revision of this YANG module can be obtained from
        the IANA web site. website.

        Requests for new values should be made to IANA via
        email (iana@iana.org).

        Copyright (c) 2018 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject
        to the license terms contained in, the Simplified BSD License
        set forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).
        (https://trustee.ietf.org/license-info).

        The initial version of this YANG module is part of RFC XXXX; 8348;
        see the RFC itself for full legal notices.";
     reference
       // RFC Ed.: replace PPPP with actual path and remove this note.
       "https://www.iana.org/assignments/PPPP";

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.
       "https://www.iana.org/assignments/yang-parameters";

     revision 2018-01-15 2018-03-13 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: 8348: A YANG Data Model for Hardware Management";
     }

     /*
      * Identities
      */

     identity hardware-class {
       description
         "This identity is the base for all hardware class
          identifiers.";
     }

     identity unknown {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is unknown
          to the server.";
     }

     identity chassis {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is an
          overall container for networking equipment.  Any class of
          physical component, except a stack, may be contained within a
          chassis; a chassis may only be contained within a stack.";
     }

     identity backplane {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of device for aggregating and forwarding networking traffic,
          such as a shared backplane in a modular ethernet switch.  Note
          that an implementation may model a backplane as a single
          physical component, which is actually implemented as multiple
          discrete physical components (within a chassis or stack).";
     }

     identity container {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is capable
          of containing one or more removable physical entities,
          possibly of different types.  For example, each (empty or
          full) slot in a chassis will be modeled as a container.  Note
          that all removable physical components should be modeled
          within a container component, such as field-replaceable
          modules, fans, or power supplies.  Note that all known
          containers should be modeled by the agent, including empty
          containers.";
     }

     identity power-supply {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is a
          power-supplying component.";
     }

     identity fan {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is a fan or
          other heat-reduction component.";
     }

     identity sensor {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of sensor, such as a temperature sensor within a router
          chassis.";
     }

     identity module {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of self-contained sub-system.  If a module component is
          removable, then it should be modeled within a container
          component; otherwise, it should be modeled directly within
          another physical component (e.g., a chassis or another
          module).";
     }

     identity port {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of networking port, port capable of receiving and/or transmitting
          networking traffic.";
     }

     identity stack {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of super-container (possibly virtual) intended to group
          together multiple chassis entities.  A stack may be realized
          by a virtual cable, a real interconnect cable attached to
          multiple chassis, or multiple interconnect cables.  A stack
          should not be modeled within any other physical components,
          but a stack may be contained within another stack.  Only
          chassis components should be contained within a stack.";
     }

     identity cpu {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of central processing unit.";
     }

     identity energy-object {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of energy object, i.e., it is a piece of equipment that is
          part of or attached to a communications network that is
          monitored, it is controlled, or it aids in the management of
          another device for Energy Management.";
     }

     identity battery {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of battery.";
     }

     identity storage-drive {
       base ianahw:hardware-class;
       description
         "This identity is applicable if the hardware class is some sort
          of component with data storage capability as its main
          functionality, e.g., hard disk drive (HDD), solid state solid-state device
          (SSD), solid-state hybrid drive (SSHD), object storage (OSD) device
          (OSD), or other.";
     }
   }

   <CODE ENDS>

8.  IANA Considerations

   This document defines the initial version of the IANA-maintained
   "iana-hardware" YANG module.

   The "iana-hardware" YANG module is intended to reflect the
   "IANA-ENTITY-MIB" MIB module so that if a new enumeration is added to
   the "IANAPhysicalClass" TEXTUAL-CONVENTION, textual convention, the same class is added
   as an identity derived from "ianahw:hardware-class".

   When the "iana-hardware" YANG module is updated, a new "revision"
   statement must be added in front of the existing revision statements.

8.1.  URI Registrations

   This document registers three URIs in the IETF "IETF XML registry Registry"
   [RFC3688].  Following  Per the format in RFC 3688, the following registrations are requested to be
   have been made.

     URI: urn:ietf:params:xml:ns:yang:iana-hardware
     Registrant Contact: The IESG.
     XML: N/A, the requested URI is an XML namespace.

     URI: urn:ietf:params:xml:ns:yang:ietf-hardware
     Registrant Contact: The IESG.
     XML: N/A, the requested URI is an XML namespace.

     URI: urn:ietf:params:xml:ns:yang:ietf-hardware-state
     Registrant Contact: The IESG.
     XML: N/A, the requested URI is an XML namespace.

8.2.  YANG Module Registrations

   This document registers three YANG modules in the YANG "YANG Module Names Names"
   registry [RFC6020].

     name:         iana-hardware
     namespace:    urn:ietf:params:xml:ns:yang:iana-hardware
     prefix:       ianahw
     reference:    RFC XXXX 8348

     name:         ietf-hardware
     namespace:    urn:ietf:params:xml:ns:yang:ietf-hardware
     prefix:       hw
     reference:    RFC XXXX 8348

     name:         ietf-hardware-state
     namespace:    urn:ietf:params:xml:ns:yang:ietf-hardware-state
     prefix:       hw-state
     reference:    RFC XXXX 8348

9.  Security Considerations

   The YANG modules specified in this document define a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC5246].

   The NETCONF access control model [RFC6536] [RFC8341] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   There are a number of data nodes defined in the YANG module
   "ietf-hardware" "ietf-
   hardware" that are writable/creatable/deletable (i.e., config true,
   which is the default).  These data nodes may be considered sensitive
   or vulnerable in some network environments.  Write operations (e.g.,
   edit-config) to these data nodes without proper protection can have a
   negative effect on network operations.  These are the subtrees and
   data nodes and their sensitivity/vulnerability:

   /hardware/component/admin-state:  Setting this node to 'locked' or
      'shutting-down' can cause disruption of services ranging from
      those running on a port to those on an entire device, depending on
      the type of component.

   Some of the readable data nodes in these YANG modules may be
   considered sensitive or vulnerable in some network environments.  It
   is thus important to control read access (e.g., via get, get-config,
   or notification) to these data nodes.  These are the subtrees and
   data nodes and their sensitivity/vulnerability:

   /hardware/component:  The leafs in this list expose information about
      the physical components in a device, which may be used to identify
      the vendor, model, version, and specific device-identification
      information of each system component.

   /hardware/component/sensor-data/value:  This node may expose the
      values of particular physical sensors in a device.

   /hardware/component/state:  Access to this node allows one to figure
      out what the active and standby resources in a device are.

10.  Acknowledgments

   The authors wish to thank the following individuals, who all provided
   helpful comments on various draft versions of this document: Bart
   Bogaert, Timothy Carey, William Lupton, Juergen Schoenwaelder.

11.  References

11.1.

10.1.  Normative References

   [I-D.ietf-netmod-revised-datastores]
              Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore
              Architecture", draft-ietf-netmod-revised-datastores-10
              (work in progress), January 2018.

   [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>.
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3433]  Bierman, A., Romascanu, D., and K. Norseth, "Entity Sensor
              Management Information Base", RFC 3433,
              DOI 10.17487/RFC3433, December 2002, <https://www.rfc-
              editor.org/info/rfc3433>.
              <https://www.rfc-editor.org/info/rfc3433>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004, <https://www.rfc-
              editor.org/info/rfc3688>.
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC4268]  Chisholm, S. and D. Perkins, "Entity State MIB", RFC 4268,
              DOI 10.17487/RFC4268, November 2005, <https://www.rfc-
              editor.org/info/rfc4268>.
              <https://www.rfc-editor.org/info/rfc4268>.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008, <https://www.rfc-
              editor.org/info/rfc5246>.
              <https://www.rfc-editor.org/info/rfc5246>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010, <https://www.rfc-
              editor.org/info/rfc6020>.
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              DOI 10.17487/RFC6536, March 2012, <https://www.rfc-
              editor.org/info/rfc6536>.

   [RFC6933]  Bierman, A., Romascanu, D., Quittek, J., and M.
              Chandramouli, "Entity MIB (Version 4)", RFC 6933,
              DOI 10.17487/RFC6933, May 2013, <https://www.rfc-
              editor.org/info/rfc6933>.
              <https://www.rfc-editor.org/info/rfc6933>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [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>.

11.2.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

10.2.  Informative References

   [I-D.ietf-netmod-yang-tree-diagrams]

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", draft-
              ietf-netmod-yang-tree-diagrams-04 (work in progress),
              December 2017.
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Appendix A.  Hardware State Data Model

   This non-normative appendix contains a data model designed as a
   temporary solution for implementations that do not yet support the
   Network Management Datastore Architecture (NMDA) defined in
   [I-D.ietf-netmod-revised-datastores].
   [RFC8342].  It has the following structure:

   module: ietf-hardware-state
     x--ro hardware
        x--ro last-change?   yang:date-and-time
        x--ro component* [name]
           x--ro name              string
           x--ro class             identityref
           x--ro physical-index?   int32 {entity-mib}?
           x--ro description?      string
           x--ro parent?           -> ../../component/name
           x--ro parent-rel-pos?   int32
           x--ro contains-child*   -> ../../component/name
           x--ro hardware-rev?     string
           x--ro firmware-rev?     string
           x--ro software-rev?     string
           x--ro serial-num?       string
           x--ro mfg-name?         string
           x--ro model-name?       string
           x--ro alias?            string
           x--ro asset-id?         string
           x--ro is-fru?           boolean
           x--ro mfg-date?         yang:date-and-time
           x--ro uri*              inet:uri
           x--ro uuid?             yang:uuid
           x--ro state {hardware-state}?
           |  x--ro state-last-changed?   yang:date-and-time
           |  x--ro admin-state?          hw:admin-state
           |  x--ro oper-state?           hw:oper-state
           |  x--ro usage-state?          hw:usage-state
           |  x--ro alarm-state?          hw:alarm-state
           |  x--ro standby-state?        hw:standby-state
           x--ro sensor-data {hardware-sensor}?
              x--ro value?               hw:sensor-value
              x--ro value-type?          hw:sensor-value-type
              x--ro value-scale?         hw:sensor-value-scale
              x--ro value-precision?     hw:sensor-value-precision
              x--ro oper-status?         hw:sensor-status
              x--ro units-display?       string
              x--ro value-timestamp?     yang:date-and-time
              x--ro value-update-rate?   uint32
     notifications:
       x---n hardware-state-change
       x---n hardware-state-oper-enabled {hardware-state}?
       |  x--ro name?          -> /hardware/component/name
       |  x--ro admin-state?   -> /hardware/component/state/admin-state
       |  x--ro alarm-state?   -> /hardware/component/state/alarm-state
       x---n hardware-state-oper-disabled {hardware-state}?
          x--ro name?          -> /hardware/component/name
          x--ro admin-state?   -> /hardware/component/state/admin-state
          x--ro alarm-state?   -> /hardware/component/state/alarm-state

A.1.  Hardware State YANG Module

   <CODE BEGINS> file "ietf-hardware-state@2017-12-18.yang" "ietf-hardware-state@2018-03-13.yang"

   module ietf-hardware-state {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-hardware-state";
     prefix hw-state;

     import ietf-inet-types {
       prefix inet;
     }
     import ietf-yang-types {
       prefix yang;
     }
     import iana-hardware {
       prefix ianahw;
     }
     import ietf-hardware {
       prefix hw;
     }

     organization
       "IETF NETMOD (Network Modeling) Working Group";

     contact
       "WG Web:   <http://tools.ietf.org/wg/netmod/>   <https://datatracker.ietf.org/wg/netmod/>
        WG List:  <mailto:netmod@ietf.org>

        Editor:   Andy Bierman
                  <mailto:andy@yumaworks.com>

        Editor:   Martin Bjorklund
                  <mailto:mbj@tail-f.com>

        Editor:   Jie Dong
                  <mailto:jie.dong@huawei.com>
        Editor:   Dan Romascanu
                  <mailto:dromasca@gmail.com>";

     // RFC Ed.: replace XXXX and YYYY with actual RFC numbers and
     // remove this note. Romascanu
                  <mailto:dromasca@gmail.com>";

     description
       "This module contains a collection of YANG definitions for
        monitoring hardware.

        This data model is designed as a temporary solution for
        implementations that do not yet support the Network Management
        Datastore Architecture (NMDA) defined in RFC YYYY. 8342.  Such an
        implementation cannot implement the module 'ietf-hardware'
        properly, since without NMDA support, it is not possible to
        distinguish between instances of nodes in the running
        configuration and operational state. states.

        The data model in this module is the same as the data model in
        'ietf-hardware', except all nodes are marked as 'config false'.

        If a server that implements this module but doesn't support NMDA
        also supports configuration of hardware components, it SHOULD
        also implement the module 'ietf-hardware' in the configuration
        datastores.  The corresponding state data is found in the
        '/hw-state:hardware' subtree.

        Copyright (c) 2017 2018 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject
        to the license terms contained in, the Simplified BSD License
        set forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX; 8348; see
        the RFC itself for full legal notices.";

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.

     revision 2017-12-18 2018-03-13 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: 8348: A YANG Data Model for Hardware Management";
     }

     /*
      * Features
      */
     feature entity-mib {
       status deprecated;
       description
         "This feature indicates that the device implements
          the ENTITY-MIB.";
       reference
         "RFC 6933: Entity MIB (Version 4)";
     }

     feature hardware-state {
       status deprecated;
       description
         "Indicates the that ENTITY-STATE-MIB objects are supported";
       reference
         "RFC 4268: Entity State MIB";
     }

     feature hardware-sensor {
       status deprecated;
       description
         "Indicates the that ENTITY-SENSOR-MIB objects are supported";
       reference
         "RFC 3433: Entity Sensor MIB"; Management Information Base";
     }

     /*
      * Data nodes
      */

     container hardware {
       config false;
       status deprecated;
       description
         "Data nodes representing components.";

       leaf last-change {
         type yang:date-and-time;
         status deprecated;
         description
           "The time the '/hardware/component' list changed in the
            operational state.";
       }

       list component {
         key name;
         status deprecated;
         description
           "List of components.

            When the server detects a new hardware component, it
            initializes a list entry in the operational state.

            If the server does not support configuration of hardware
            components, list entries in the operational state are
            initialized with values for all nodes as detected by the
            implementation.

            Otherwise, the following this procedure is followed:

              1. If there is an entry in the /hardware/component '/hardware/component' list
                 in the intended configuration with values for the nodes
                 'class', 'parent', and 'parent-rel-pos' that are equal
                 to the detected values, then:

              1a. If the configured entry has a value for 'mfg-name'
                  that is equal to the detected value, value or if the
                  'mfg-name' value cannot be detected, then the list
                  entry in the operational state is initialized with the
                  configured values for all configured nodes, including
                  the 'name'.

                  Otherwise, the list entry in the operational state is
                  initialized with values for all nodes as detected by
                  the implementation.  The implementation may raise an
                  alarm that informs about the 'mfg-name' mismatch
                  condition.  How this is done is outside the scope of
                  this document.

              1b. Otherwise (i.e., there is no matching configuration
                  entry), the list entry in the operational state is
                  initialized with values for all nodes as detected by
                  the implementation.

            If the /hardware/component '/hardware/component' list in the intended
            configuration is modified, then the system MUST behave as if
            it re-initializes itself, itself and follow the procedure in (1).";
         reference
           "RFC 6933: Entity MIB (Version 4) - entPhysicalEntry";

         leaf name {
           type string;
           status deprecated;
           description
             "The name assigned to this component.

              This name is not required to be the same as
              entPhysicalName.";
         }

         leaf class {
           type identityref {
             base ianahw:hardware-class;
           }
           mandatory true;
           status deprecated;
           description
             "An indication of the general hardware type of the
              component.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalClass";
         }

         leaf physical-index {
           if-feature entity-mib;
           type int32 {
             range "1..2147483647";
           }
           status deprecated;
           description
             "The entPhysicalIndex for the entPhysicalEntry represented
              by this list entry.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalIndex";
         }

         leaf description {
           type string;
           status deprecated;
           description
             "A textual description of the component.  This node should
              contain a string that identifies the manufacturer's name
              for the component and should be set to a distinct value
              for each version or model of the component.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalDescr";
         }

         leaf parent {
           type leafref {
             path "../../component/name";
             require-instance false;
           }
           status deprecated;
           description
             "The name of the component that physically contains this
              component.

              If this leaf is not instantiated, it indicates that this
              component is not contained in any other component.

              In the event that a physical component is contained by
              more than one physical component (e.g., double-wide
              modules), this node contains the name of one of these
              components.  An implementation MUST use the same name
              every time this node is instantiated.";
           reference
             "RFC 6933: Entity MIB (Version 4) -
                        entPhysicalContainedIn";
         }

         leaf parent-rel-pos {
           type int32 {
             range "0 .. 2147483647";
           }
           status deprecated;
           description
             "An indication of the relative position of this child
              component among all its sibling components.  Sibling
              components are defined as components that:

                o Share share the same value of the 'parent' node; node and

                o Share share a common base identity for the 'class' node.

              Note that the last rule gives implementations flexibility
              in how components are numbered.  For example, some
              implementations might have a single number series for all
              components derived from 'ianahw:port', while some others
              might have different number series for different
              components with identities derived from 'ianahw:port' (for
              example, one for RJ45 and one for SFP).";

           reference
             "RFC 6933: Entity MIB (Version 4) -
                        entPhysicalParentRelPos";
         }

         leaf-list contains-child {
           type leafref {
             path "../../component/name";
           }
           status deprecated;
           description
             "The name of the contained component.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalChildIndex";
         }

         leaf hardware-rev {
           type string;
           status deprecated;
           description
             "The vendor-specific hardware revision string for the
              component.  The preferred value is the hardware revision
              identifier actually printed on the component itself (if
              present).";
           reference
             "RFC 6933: Entity MIB (Version 4) -
                        entPhysicalHardwareRev";
         }

         leaf firmware-rev {
           type string;
           status deprecated;
           description
             "The vendor-specific firmware revision string for the
              component.";
           reference
             "RFC 6933: Entity MIB (Version 4) -
                        entPhysicalFirmwareRev";
         }

         leaf software-rev {
           type string;
           status deprecated;
           description
             "The vendor-specific software revision string for the
              component.";
           reference
             "RFC 6933: Entity MIB (Version 4) -
                        entPhysicalSoftwareRev";
         }

         leaf serial-num {
           type string;
           status deprecated;
           description
             "The vendor-specific serial number string for the
              component.  The preferred value is the serial number
              string actually printed on the component itself (if
              present).";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalSerialNum";
         }

         leaf mfg-name {
           type string;
           status deprecated;
           description
             "The name of the manufacturer of this physical component.
              The preferred value is the manufacturer name string
              actually printed on the component itself (if present).

              Note that comparisons between instances of the model-name,
              firmware-rev, software-rev,
              'model-name', 'firmware-rev', 'software-rev', and the serial-num
              'serial-num' nodes are only meaningful amongst component components
              with the same value of
              mfg-name. 'mfg-name'.

              If the manufacturer name string associated with the
              physical component is unknown to the server, then this
              node is not instantiated.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalMfgName";
         }

         leaf model-name {
           type string;
           status deprecated;
           description
             "The vendor-specific model name identifier string
              associated with this physical component.  The preferred
              value is the customer-visible part number, which may be
              printed on the component itself.

              If the model name string associated with the physical
              component is unknown to the server, then this node is not
              instantiated.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalModelName";
         }

         leaf alias {
           type string;
           status deprecated;
           description
             "An 'alias' name for the component, as specified by a
              network manager, and that provides a non-volatile 'handle' for
              the component.

              If no configured value exists, the server MAY set the
              value of this node to a locally unique value in the
              operational state.

              A server implementation MAY map this leaf to the
              entPhysicalAlias MIB object.  Such an implementation needs
              to use some mechanism to handle the differences in size
              and characters allowed between this leaf and
              entPhysicalAlias.  The definition of such a mechanism is
              outside the scope of this document.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalAlias";
         }

         leaf asset-id {
           type string;
           status deprecated;
           description
             "This node is a user-assigned asset tracking identifier for
              the component.

              A server implementation MAY map this leaf to the
              entPhysicalAssetID MIB object.  Such an implementation
              needs to use some mechanism to handle the differences in
              size and characters allowed between this leaf and
              entPhysicalAssetID.  The definition of such a mechanism is
              outside the scope of this document.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalAssetID";
         }

         leaf is-fru {
           type boolean;
           status deprecated;
           description
             "This node indicates whether or not this component is
              considered a 'field replaceable 'field-replaceable unit' by the vendor.  If
              this node contains the value 'true', then this component
              identifies a field replaceable field-replaceable unit.  For all components
              that are permanently contained within a field replaceable field-replaceable
              unit, the value 'false' should be returned for this
              node.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalIsFRU";
         }

         leaf mfg-date {
           type yang:date-and-time;
           status deprecated;
           description
             "The date of manufacturing of the managed component.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalMfgDate";
         }

         leaf-list uri {
           type inet:uri;
           status deprecated;
           description
             "This node contains identification information about the
              component.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalUris";
         }

         leaf uuid {
           type yang:uuid;
           status deprecated;
           description
             "A Universally Unique Identifier of the component.";
           reference
             "RFC 6933: Entity MIB (Version 4) - entPhysicalUUID";
         }

         container state {
           if-feature hardware-state;
           status deprecated;
           description
             "State-related nodes";
           reference
             "RFC 4268: Entity State MIB";

           leaf state-last-changed {
             type yang:date-and-time;
             status deprecated;
             description
               "The date and time when the value of any of the
                admin-state, oper-state, usage-state, alarm-state, or
                standby-state changed for this component.

                If there has been no change since the last
                re-initialization of the local system, this node
                contains the date and time of local system
                initialization.  If there has been no change since the
                component was added to the local system, this node
                contains the date and time of the insertion.";
             reference
               "RFC 4268: Entity State MIB - entStateLastChanged";
           }

           leaf admin-state {
             type hw:admin-state;
             status deprecated;
             description
               "The administrative state for this component.

                This node refers to a component's administrative
                permission to service both other components within its
                containment hierarchy as well as other users of its
                services defined by means outside the scope of this
                module.

                Some components exhibit only a subset of the remaining
                administrative state values.  Some components cannot be
                locked, and hence
                locked; hence, this node exhibits only the 'unlocked'
                state.  Other components cannot be shutdown gracefully,
                and hence shut down gracefully;
                hence, this node does not exhibit the 'shutting-down'
                state.";
             reference
               "RFC 4268: Entity State MIB - entStateAdmin";
           }

           leaf oper-state {
             type hw:oper-state;
             status deprecated;
             description
               "The operational state for this component.

                Note that this node does not follow the administrative
                state.  An administrative state of down 'down' does not
                predict an operational state of disabled. 'disabled'.

                Note that some implementations may not be able to
                accurately report oper-state while the admin-state node
                has a value other than 'unlocked'.  In these cases, this
                node MUST have a value of 'unknown'.";
             reference
               "RFC 4268: Entity State MIB - entStateOper";
           }

           leaf usage-state {
             type hw:usage-state;
             status deprecated;
             description
               "The usage state for this component.

                This node refers to a component's ability to service
                more components in a containment hierarchy.

                Some components will exhibit only a subset of the usage
                state values.  Components that are unable to ever
                service any components within a containment hierarchy
                will always have a usage state of 'busy'.  Some
                components  In some
                cases, a component will only ever be able to support only one
                other component within its containment hierarchy and
                will therefore only exhibit values of 'idle' and
                'busy'.";
             reference
               "RFC 4268, 4268: Entity State MIB - entStateUsage";
           }

           leaf alarm-state {
             type hw:alarm-state;
             status deprecated;
             description
               "The alarm state for this component.  It does not
                include the alarms raised on child components within its
                containment hierarchy.";
             reference
               "RFC 4268: Entity State MIB - entStateAlarm";
           }

           leaf standby-state {
             type hw:standby-state;
             status deprecated;
             description
               "The standby state for this component.

                Some components will exhibit only a subset of the
                remaining standby state values.  If this component
                cannot operate in a standby role, the value of this node
                will always be 'providing-service'.";
             reference
               "RFC 4268: Entity State MIB - entStateStandby";
           }
         }
         container sensor-data {
           when 'derived-from-or-self(../class,
                                      "ianahw:sensor")' {
             description
               "Sensor data nodes present for any component of type
                'sensor'";
           }
           if-feature hardware-sensor;
           status deprecated;

           description
             "Sensor-related nodes.";
           reference
             "RFC 3433: Entity Sensor MIB"; Management Information Base";

           leaf value {
             type hw:sensor-value;
             status deprecated;
             description
               "The most recent measurement obtained by the server
                for this sensor.

                A client that periodically fetches this node should also
                fetch the nodes 'value-type', 'value-scale', and
                'value-precision', since they may change when the value
                is changed.";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorValue";
           }

           leaf value-type {
             type hw:sensor-value-type;
             status deprecated;
             description
               "The type of data units associated with the
                sensor value";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorType";
           }

           leaf value-scale {
             type hw:sensor-value-scale;
             status deprecated;
             description
               "The (power of 10) scaling factor associated
                with the sensor value";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorScale";
           }

           leaf value-precision {
             type hw:sensor-value-precision;
             status deprecated;
             description
               "The number of decimal places of precision
                associated with the sensor value";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorPrecision";
           }

           leaf oper-status {
             type hw:sensor-status;
             status deprecated;
             description
               "The operational status of the sensor.";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorOperStatus";
           }

           leaf units-display {
             type string;
             status deprecated;
             description
               "A textual description of the data units that should be
                used in the display of the sensor value.";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorUnitsDisplay";
           }

           leaf value-timestamp {
             type yang:date-and-time;
             status deprecated;
             description
               "The time the status and/or value of this sensor was last
                obtained by the server.";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorValueTimeStamp";
           }
           leaf value-update-rate {
             type uint32;
             units "milliseconds";
             status deprecated;
             description
               "An indication of the frequency that the server updates
                the associated 'value' node, representing represented in
                milliseconds.  The value zero indicates:

                 - the sensor value is updated on demand (e.g.,
                   when polled by the server for a get-request),

                 - the sensor value is updated when the sensor
                   value changes (event-driven), or

                 - the server does not know the update rate.";
             reference
               "RFC 3433: Entity Sensor Management Information Base -
                          entPhySensorValueUpdateRate";
           }
         }
       }
     }

     /*
      * Notifications
      */

     notification hardware-state-change {
       status deprecated;
       description
         "A hardware-state-change notification is generated when the
          value of /hardware/last-change changes in the operational
          state.";
       reference
         "RFC 6933, 6933: Entity MIB (Version 4) - entConfigChange";
     }

     notification hardware-state-oper-enabled {
       if-feature hardware-state;
       status deprecated;
       description
         "A hardware-state-oper-enabled notification signifies that a
          component has transitioned into the 'enabled' state.";

       leaf name {
         type leafref {
           path "/hardware/component/name";
         }
         status deprecated;
         description
           "The name of the component that has transitioned into the
            'enabled' state.";
       }
       leaf admin-state {
         type leafref {
           path "/hardware/component/state/admin-state";
         }
         status deprecated;
         description
           "The administrative state for the component.";
       }
       leaf alarm-state {
         type leafref {
           path "/hardware/component/state/alarm-state";
         }
         status deprecated;
         description
           "The alarm state for the component.";
       }
       reference
         "RFC 4268, 4268: Entity State MIB - entStateOperEnabled";
     }

     notification hardware-state-oper-disabled {
       if-feature hardware-state;
       status deprecated;
       description
         "A hardware-state-oper-disabled notification signifies that a
          component has transitioned into the 'disabled' state.";

       leaf name {
         type leafref {
           path "/hardware/component/name";
         }
         status deprecated;
         description
           "The name of the component that has transitioned into the
            'disabled' state.";
       }
       leaf admin-state {
         type leafref {
           path "/hardware/component/state/admin-state";
         }
         status deprecated;
         description
           "The administrative state for the component.";
       }
       leaf alarm-state {
         type leafref {
           path "/hardware/component/state/alarm-state";
         }
         status deprecated;
         description
           "The alarm state for the component.";
       }
       reference
         "RFC 4268, 4268: Entity State MIB - entStateOperDisabled";
     }

   }

   <CODE ENDS>

Acknowledgments

   The authors wish to thank the following individuals, who all provided
   helpful comments on various draft versions of this document: Bart
   Bogaert, Timothy Carey, William Lupton, and Juergen Schoenwaelder.

Authors' Addresses

   Andy Bierman
   YumaWorks

   Email: andy@yumaworks.com

   Martin Bjorklund
   Tail-f Systems

   Email: mbj@tail-f.com

   Jie Dong
   Huawei Technologies

   Email: jie.dong@huawei.com

   Dan Romascanu

   Email: dromasca@gmail.com