RFC 8348
A YANG Data Model for Hardware Management
RFC 8348: A YANG Data Model for Hardware Management 💖
Okay bestie, so this one is RFC 8348 🎀, and it's a Standards Track document, which means it's a real IETF standard and not just a suggestion 👑. It came out in March 2018 and it's titled "A YANG Data Model for Hardware Management" ✨. The authors are A. Bierman (YumaWorks), M. Bjorklund (Tail-f Systems), J. Dong (Huawei Technologies), and D. Romascanu (no affiliation listed). It's published under ISSN 2070-1721. The title block doesn't list anything it obsoletes or updates, so nothing to track there 🙈.
Abstract
okay so the whole point of this doc is to define a YANG data model for managing the hardware on a single server 🖥️💅
Status of This Memo
This is an Internet Standards Track document, and it's a product of the Internet Engineering Task Force (IETF) 🌈. It represents the consensus of the IETF community and it got public review, then the Internet Engineering Steering Group (IESG) approved it for publication. If you want more info on Internet Standards, check out Section 2 of RFC 7841 📚.
Want the current status, any errata, or a way to give feedback? Go to 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 (https://trustee.ietf.org/license-info) as they stand on the date of publication. Please actually read these, bestie, because they spell out your rights and restrictions for this document 🙈. If you pull Code Components out of this document, they must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions, and they come with no warranty, as the Simplified BSD License describes.
Table of Contents
1. Introduction ....................................................3
1.1. Terminology ................................................3
1.2. Tree Diagrams ..............................................3
2. Objectives ......................................................4
3. Hardware Data Model .............................................4
3.1. The Components Lists .......................................5
4. Relationship to ENTITY-MIB ......................................6
5. Relationship to ENTITY-SENSOR-MIB ...............................8
6. Relationship to ENTITY-STATE-MIB ................................8
7. Hardware YANG Modules ...........................................9
7.1. "ietf-hardware" Module .....................................9
7.2. "iana-hardware" Module ....................................34
8. IANA Considerations ............................................38
8.1. URI Registrations .........................................38
8.2. YANG Module Registrations .................................39
9. Security Considerations ........................................39
10. References ....................................................40
10.1. Normative References .....................................40
10.2. Informative References ...................................41
Appendix A. Hardware State Data Model ............................42
A.1. Hardware State YANG Module ................................43
Acknowledgments ...................................................60
Authors' Addresses ................................................601. Introduction ✨
This doc defines a YANG data model [RFC7950] for managing hardware on a single server 🖥️.
The data model covers both configuration and system state, which means status info and counters for the statistics collection 📊.
The data model in this document is designed to be compliant with the Network Management Datastore Architecture (NMDA) [RFC8342]. For implementations that don't support NMDA yet, there's a temporary module with system state data only, and it's defined in Appendix A 🧚.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here 🔥. This is super important, so pay attention!
The following terms are defined in [RFC8342] and aren't redefined here:
- client
- server
- configuration
- system state
- operational state
- intended configuration
1.2. Tree Diagrams
Tree diagrams in this document follow the notation defined in [RFC8340] 🌸.
2. Objectives
okay so this section covers some of the design objectives for the hardware data model 🎯.
- The hardware data model needs to support many common properties used to identify hardware components 🏷️.
- Important information and states about hardware components need to be collected from devices that support the hardware data model 📥.
- The hardware data model should be suitable for new implementations to use as is ✨.
- The hardware data model defined in this document can be implemented on a system that also implements ENTITY-MIB. So the mapping between the hardware data model and ENTITY-MIB should be clear 🦋.
- The data model should support pre-provisioning of hardware components 🍓.
3. Hardware Data Model 💜
This document defines the YANG module "ietf-hardware", and it's got 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-state3.1. The Components Lists
The hardware data model in this document uses a flat list of components 📋. Each component in the list is identified by its name. On top of that, every 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 use one of the common IANA-defined identities directly or derive a more specific identity from one of them 💅.
4. Relationship to ENTITY-MIB 🔗
If the device implements the ENTITY-MIB [RFC6933], then 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. The exception is entPhysicalSerialNum, which is writable in the 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's either derived from or one of the identities in the "iana-hardware" module, then entPhysicalClass contains the matching 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, and then use that identity for the "class" leaf 🌈.
Here's the table of YANG data nodes and their matching ENTITY-MIB objects, so you can see the whole mapping at once 🍓:
+--------------------------------+----------------------------------+
| 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 ObjectsTo be continued, bestie 🫶✨
5. Relationship to ENTITY-SENSOR-MIB ✨
Okay so, if the device implements the ENTITY-SENSOR-MIB [RFC3433], then each entry in the "/hardware/component" list where the container "sensor-data" exists gets mapped to one EntPhySensorEntry. 🦋
Here's the cute table of which YANG data nodes line up with which ENTITY-SENSOR-MIB objects 💖
+-------------------------------------+-----------------------------+
| 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 Objects6. Relationship to ENTITY-STATE-MIB 🌸
Same vibe here: if the device implements the ENTITY-STATE-MIB [RFC4268], each entry in the "/hardware/component" list where the container "state" exists gets mapped to one EntStateEntry. 🧚
And the table that pairs them up:
+------------------------------------------+------------------------+
| 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 Objects7. Hardware YANG Modules 💜
7.1. "ietf-hardware" Module 🎀
Okay bestie, this YANG module imports typedefs from [RFC6991]. 💅
<CODE BEGINS> file "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: <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>";
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 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 8348; see
the RFC itself for full legal notices.";
revision 2018-03-13 {
description
"Initial revision.";
reference
"RFC 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 that ENTITY-STATE-MIB objects are supported";
reference
"RFC 4268: Entity State MIB";
}
feature hardware-sensor {
description
"Indicates that ENTITY-SENSOR-MIB objects are supported";
reference
"RFC 3433: Entity Sensor 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.";
}
}
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, 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: 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 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 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 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 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 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).
If the associated sensor-value-type node is equal to 'other' or
'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)
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, this procedure is followed:
1. If there is an entry in the '/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' list in the intended
configuration is modified, then the system MUST behave as if
it re-initializes 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.";
}okay that's the whole sensor vibe wrapped up 💅 we went from the sensor-value-type enums (volts, amps, watts, the works 🔥) to the scales from yocto all the way up to yotta 🌈, then the precision and value rules, the status trio ✨, and the hardware container + component list finally kicking off 🧚
okay bestie, the component list keeps going 💖 Here's the class leaf and the stuff around it.
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";
}So class is the general hardware type, and it's mandatory 🎀. physical-index is the link back to the old-school entPhysicalIndex, and description is the manufacturer-name-plus-version vibe 🌸.
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 the same value of the 'parent' node and
o 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 registered jack 45 (RJ45) and one for
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";
}Okay the parent leaf is the "which box am I inside" pointer 🧚, and there's a MUST in there about using the same name every time, so pay attention to that one ✨. parent-rel-pos is the sibling numbering thing, and it's giving flexibility 🦋 because implementations get to pick their own number series. contains-child is the reverse, the list of kids 👑.
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', and
'serial-num' nodes are only meaningful amongst components
with the same value of '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";
}Now the revision and identity bits 🌈. hardware-rev, firmware-rev, software-rev and serial-num are all vendor strings, and the vibe is "use the stuff printed on the box if it's there" 📦. For mfg-name, the thing to remember is that you can only really compare model-name, firmware-rev, software-rev and serial-num when the mfg-name matches 💅. And model-name is the customer-visible part number, so it's the one you'd actually read off a sticker 🍓.
leaf alias {
type string;
description
"An 'alias' name for the component, as specified by a
network manager, 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 unit' by the vendor. If
this node contains the value 'true', then this component
identifies a field-replaceable unit. For all components
that are permanently contained within a 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";
}Labels and tracking time 🏷️. alias is the non-volatile nickname a network manager can set, and the server MAY fill in a locally unique one if nothing's configured 🌟. asset-id is the user-assigned tracking tag 🦋. is-fru says whether the vendor calls it a field-replaceable unit, and it's a "should" 🙈 situation for the parts permanently inside a FRU. Then mfg-date, uri and uuid finish up the identity crew 💜.
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; hence, this node exhibits only the 'unlocked'
state. Other components cannot be 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' does not
predict an operational state of '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";
}Last but not least, the state container 🔥. It's behind hardware-state, and it holds the timestamp for when any of the state values last changed, plus admin-state and oper-state. The big tea ☕ is that oper-state is not tied to admin-state, so a "down" admin doesn't automatically mean "disabled" operationally. And when a server can't report oper-state accurately while admin isn't unlocked, this node MUST say unknown 💀. Iconic honesty 💅✨
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'. In some cases, a component will 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: 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"; } }
Okay so next up is the sensor-data container, and it's giving main character energy 🌡️✨ It only shows up for components whose class is derived from (or is) ianahw:sensor, and the whole thing is gated behind the hardware-sensor feature 💖
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 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, 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"; } } } }
Now for the notifications 🔔 bestie, these are the moments the server pings you when something changes. The hardware-state-change one fires when /hardware/last-change changes in the operational state, and the oper-enabled and oper-disabled ones signal a component going enabled or disabled 🦋
/*
- 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: 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: 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: Entity State MIB - entStateOperDisabled"; }
}
<CODE ENDS>
7.2. "iana-hardware" Module ✨
Okay, this is the IANA-maintained one 🌸 It's the module that holds all the hardware class identities, and the file is named after its revision date.
<CODE BEGINS> file "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>";
description
"IANA-defined identities for hardware class.
The latest revision of this YANG module can be obtained from
the IANA 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
(https://trustee.ietf.org/license-info).
The initial version of this YANG module is part of RFC 8348;
see the RFC itself for full legal notices.";
reference
"https://www.iana.org/assignments/yang-parameters";
revision 2018-03-13 {
description
"Initial revision.";
reference
"RFC 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 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 device
(SSD), solid-state hybrid drive (SSHD), object storage device
(OSD), or other.";
}
}
<CODE ENDS>8. IANA Considerations 🦋
This doc defines the very first version of the IANA-maintained "iana-hardware" YANG module, so it's the origin story bestie 💜
The "iana-hardware" module is meant to mirror the "IANA-ENTITY-MIB" MIB module. That means if someone adds a new value to the IANAPhysicalClass textual convention, the same class shows up as an identity derived from ianahw:hardware-class too. Matching energy ✨
When the "iana-hardware" YANG module gets updated, a new "revision" statement must be added in front of the existing revision statements. Newest first, always 🫶
8.1. URI Registrations 🎀
This document registers three URIs in the "IETF XML Registry" [RFC3688]. The registrations follow the format from RFC 3688, and they've all 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 Module Names" registry [RFC6020]. Here's the lineup 👑
name: iana-hardware
namespace: urn:ietf:params:xml:ns:yang:iana-hardware
prefix: ianahw
reference: RFC 8348
name: ietf-hardware
namespace: urn:ietf:params:xml:ns:yang:ietf-hardware
prefix: hw
reference: RFC 8348
name: ietf-hardware-state
namespace: urn:ietf:params:xml:ns:yang:ietf-hardware-state
prefix: hw-state
reference: RFC 83489. Security Considerations 💀
Okay, this section is serious business, so read it slowly 🥺 The YANG modules here describe a schema for data that's meant to be reached through network management protocols like 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 [RFC8341] lets you restrict particular NETCONF or RESTCONF users to a preconfigured subset of the protocol operations and content available to them. Main character access control 🔥
There are a bunch of data nodes in the "ietf-hardware" module that can be written, created, or deleted (that's config true, the default). These nodes may be sensitive or vulnerable in some network environments, and writing to them without proper protection can have a negative effect on network operations. Here are the subtrees and nodes, plus their sensitivity:
/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 modules may also be sensitive or vulnerable in some network environments, so it's important to control read access to them (for example, via get, get-config, or notification). Here's the rundown 👀
/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. References 📚
10.1. Normative References
okay bestie, here are the receipts 🧾✨ these are the docs the main text leans on hardest, so they're basically required reading 📚
- [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>.
- [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>.
- [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, <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>.
- [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>.
- [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>.
- [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>.
- [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>.
- [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>.
- [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
extra reading time 🦋 these ones are helpful background, but you don't need them to get the main idea 💜
- [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, <https://www.rfc-editor.org/info/rfc8340>.
Appendix A. Hardware State Data Model ✨
okay so this appendix is totally non-normative, which means it's a helper and not the rulebook 🫶 it's a temporary solution for implementations that don't support the Network Management Datastore Architecture (NMDA) from [RFC8342] yet. here's the 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-stateA.1. Hardware State YANG Module
here's the actual YANG module, straight from the source 💅🎀
<CODE BEGINS> file "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: <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>";
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 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 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) 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 8348; see
the RFC itself for full legal notices.";
revision 2018-03-13 {
description
"Initial revision.";
reference
"RFC 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 that ENTITY-STATE-MIB objects are supported";
reference
"RFC 4268: Entity State MIB";
}
feature hardware-sensor {
status deprecated;
description
"Indicates that ENTITY-SENSOR-MIB objects are supported";
reference
"RFC 3433: Entity Sensor 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, this procedure is followed:
1. If there is an entry in the '/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 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.okay so we're back in the YANG module and this part is SO juicy 💅
If the '/hardware/component' list in the intended
configuration is modified, then the system MUST behave as if
it re-initializes 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 the same value of the 'parent' node and
o 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', and
'serial-num' nodes are only meaningful amongst components
with the same value of '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, 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 unit' by the vendor. If
this node contains the value 'true', then this component
identifies a field-replaceable unit. For all components
that are permanently contained within a 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.to be continued, bestie 🦋 more YANG drama coming in the next part 💖
Some components exhibit only a subset of the remaining
administrative state values. Some components cannot be
locked; hence, this node exhibits only the 'unlocked'
state. Other components cannot be 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' does not
predict an operational state of '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'. In some
cases, a component will 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: 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 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, 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: 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: 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: Entity State MIB - entStateOperDisabled";
}
}
<CODE ENDS>Acknowledgments ✨
Huge thank-you 🫶 to the squad who dropped super helpful comments on the various draft versions of this doc: Bart Bogaert, Timothy Carey, William Lupton, and Juergen Schoenwaelder 💖 literally couldn't have done it without you bestie 🌸
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
📦 where this page comes from
- ietf: rfc8348 2018-03
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms