All MIBs › ENTITY-MIB
Organization: IETF ENTMIB Working Group
Last Updated: 2005-08-10
Category: Hardware and Environment
Description:
Provides management information about the physical and logical components of a system, including hardware inventory such as fans, sensors, modules, serial numbers, and model information.
Imported Objects
From SNMP-FRAMEWORK-MIB
| SnmpAdminString |
From SNMPv2-CONF
| MODULE-COMPLIANCE | |
| OBJECT-GROUP |
From SNMPv2-SMI
| Integer32 | |
| MODULE-IDENTITY | |
| OBJECT-TYPE | |
| mib-2 |
From SNMPv2-TC
| DateAndTime | |
| RowStatus | |
| TEXTUAL-CONVENTION | |
| TruthValue |
What Is ENTITY-MIB?
ENTITY-MIB is a vendor-neutral IETF standards module (RFC 6933) that provides a physical and logical inventory model for representing the components of a networking device — chassis, modules, power supplies, fans, sensors, and ports — as entries in the entPhysicalTable. It exposes hardware inventory data including component descriptions, vendor type, physical containment hierarchy, and component class (entPhysicalDescr, entPhysicalVendorType, entPhysicalContainedIn, entPhysicalClass, entPhysicalParentRelPos) -- with the entity-mib entPhysicalDescr OID serving as the primary human-readable label for each entry -- as well as revision identifiers (entPhysicalHardwareRev, entPhysicalFirmwareRev, entPhysicalSoftwareRev). This makes it a central module for monitoring hardware and software status: an operator can enumerate every physical component in a chassis, confirm which slot a module is inserted in, and verify hardware, firmware, and software revision levels are consistent across redundant components such as fans, power supplies, or line cards. Many vendor-specific hardware monitoring MIBs, for environment, power, and sensor data, reference entPhysicalIndex from this module to associate their own readings with a specific physical component, making ENTITY-MIB a common dependency for hardware-health MIBs. It is deployed on virtually any modular or chassis-based networking device — routers, switches, and multi-slot platforms — where representing physical component inventory and hierarchy is needed.
IPNetwork Monitor allows you to monitor SNMP objects defined in ENTITY-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.
What Can Be Monitored
- physical component inventory
- component containment hierarchy (slot/parent relationships)
- hardware revision level
- firmware revision level
- software revision level
- component vendor type and class
Supported Devices
- vendor-neutral, standards-based MIB, not tied to a specific manufacturer
- applies to any modular or chassis-based networking device (routers, switches)
Monitoring Examples
An administrator would walk entPhysicalTable/entPhysicalEntry to enumerate all physical components in a chassis, checking entPhysicalClass to distinguish a fan tray or power supply from a line card, and entPhysicalContainedIn to confirm which parent slot each sub-component belongs to. They would compare entPhysicalHardwareRev and entPhysicalFirmwareRev across redundant power supplies or modules to catch a mismatched firmware version after a partial upgrade, and check entPhysicalName to identify the specific component (for example 'Fan Tray 1') referenced in an alert from a vendor-specific environment MIB that uses the same entPhysicalIndex.
OIDs
| OID symbolic | OID numeric | Type | Access | Description |
|---|---|---|---|---|
| entityMIB | 1.3.6.1.2.1.47 | The Entity MIB (Version 3). | ||
| entityMIBObjects | 1.3.6.1.2.1.47.1 | |||
| entityPhysical | 1.3.6.1.2.1.47.1.1 | |||
| entPhysicalTable | 1.3.6.1.2.1.47.1.1.1 | not-accessible | This table contains one row per physical component. | |
| entPhysicalEntry | 1.3.6.1.2.1.47.1.1.1.1 | not-accessible | Entry for a physical component. | |
| PHY entPhysicalIndex | 1.3.6.1.2.1.47.1.1.1.1.1 | PhysicalIndex | read-only | The index for this entry. |
| STR entPhysicalDescr | 1.3.6.1.2.1.47.1.1.1.1.2 | SnmpAdminString | read-only | A textual description of physical component. |
| OID entPhysicalVendorType | 1.3.6.1.2.1.47.1.1.1.1.3 | OBJECT IDENTIFIER | read-only | An indication of the vendor-specific hardware type of the physical component. |
| PHY entPhysicalContainedIn | 1.3.6.1.2.1.47.1.1.1.1.4 | PhysicalIndexOrZero | read-only | The value of entPhysicalIndex for the physical entity which 'contains' this physical component. |
| PHY entPhysicalClass | 1.3.6.1.2.1.47.1.1.1.1.5 | PhysicalClass | read-only | An indication of the general hardware type of the physical component. |
| I32 entPhysicalParentRelPos | 1.3.6.1.2.1.47.1.1.1.1.6 | Integer32 | read-only | An indication of the relative position of this child component among all its sibling components. |
| STR entPhysicalName | 1.3.6.1.2.1.47.1.1.1.1.7 | SnmpAdminString | read-only | The textual name of the physical component. |
| STR entPhysicalHardwareRev | 1.3.6.1.2.1.47.1.1.1.1.8 | SnmpAdminString | read-only | The vendor-specific hardware revision string for the physical component. |
| STR entPhysicalFirmwareRev | 1.3.6.1.2.1.47.1.1.1.1.9 | SnmpAdminString | read-only | The vendor-specific firmware revision string for the physical component. |
| STR entPhysicalSoftwareRev | 1.3.6.1.2.1.47.1.1.1.1.10 | SnmpAdminString | read-only | The vendor-specific software revision string for the physical component. |
| STR entPhysicalSerialNum | 1.3.6.1.2.1.47.1.1.1.1.11 | SnmpAdminString | read-write | The vendor-specific serial number string for the physical component. |
| STR entPhysicalMfgName | 1.3.6.1.2.1.47.1.1.1.1.12 | SnmpAdminString | read-only | The name of the manufacturer of this physical component. |
| STR entPhysicalModelName | 1.3.6.1.2.1.47.1.1.1.1.13 | SnmpAdminString | read-only | The vendor-specific model name identifier string. |
| STR entPhysicalAlias | 1.3.6.1.2.1.47.1.1.1.1.14 | SnmpAdminString | read-write | This object is an 'alias' name for the physical component. |
| STR entPhysicalAssetID | 1.3.6.1.2.1.47.1.1.1.1.15 | SnmpAdminString | read-write | This object is a user-assigned asset tracking identifier. |
| T/F entPhysicalIsFRU | 1.3.6.1.2.1.47.1.1.1.1.16 | TruthValue | read-only | This object indicates whether or not this physical component is considered a field replaceable unit (FRU). |
| DAT entPhysicalMfgDate | 1.3.6.1.2.1.47.1.1.1.1.17 | DateAndTime | read-only | This object contains the date of manufacturing of the managed component. |
| OCT entPhysicalUris | 1.3.6.1.2.1.47.1.1.1.1.18 | OCTET STRING | read-write | This object contains additional identification information. |
| entityLogical | 1.3.6.1.2.1.47.1.2 | |||
| entLogicalTable | 1.3.6.1.2.1.47.1.2.1 | not-accessible | This table contains one row per logical entity. | |
| entLogicalEntry | 1.3.6.1.2.1.47.1.2.1.1 | not-accessible | Entry for a logical entity. | |
| I32 entLogicalIndex | 1.3.6.1.2.1.47.1.2.1.1.1 | Integer32 | read-only | The value of this object uniquely identifies the logical entity. |
| STR entLogicalDescr | 1.3.6.1.2.1.47.1.2.1.1.2 | SnmpAdminString | read-only | A textual description of the logical entity. |
| OID entLogicalType | 1.3.6.1.2.1.47.1.2.1.1.3 | OBJECT IDENTIFIER | read-only | An indication of the type of logical entity. |
| OCT entLogicalCommunity | 1.3.6.1.2.1.47.1.2.1.1.4 | OCTET STRING | read-only | An SNMPv1 or SNMPv2C community-string. |
| OCT entLogicalTAddress | 1.3.6.1.2.1.47.1.2.1.1.5 | OCTET STRING | read-only | The transport service address for this logical entity. |
| OID entLogicalTDomain | 1.3.6.1.2.1.47.1.2.1.1.6 | OBJECT IDENTIFIER | read-only | Indicates the kind of transport service. |
| OCT entLogicalContextEngineID | 1.3.6.1.2.1.47.1.2.1.1.7 | OCTET STRING | read-only | The authoritative SNMP engine identifier. |
| STR entLogicalContextName | 1.3.6.1.2.1.47.1.2.1.1.8 | SnmpAdminString | read-only | The SNMP context name. |
| entityMapping | 1.3.6.1.2.1.47.1.3 | |||
| entityGeneral | 1.3.6.1.2.1.47.1.4 | |||
| entityMIBConformance | 1.3.6.1.2.1.47.2 | |||
| entityMIBCompliances | 1.3.6.1.2.1.47.2.1 | |||
| entityMIBGroups | 1.3.6.1.2.1.47.2.2 | |||
| entityPhysicalGroup | 1.3.6.1.2.1.47.2.2.1 | Physical entity objects. | ||
| entityLogicalGroup | 1.3.6.1.2.1.47.2.2.2 | Logical entity objects. | ||
| entityPhysical2Group | 1.3.6.1.2.1.47.2.2.3 | Additional physical entity objects. | ||
| entityPhysical3Group | 1.3.6.1.2.1.47.2.2.4 | Physical entity group v3. | ||
| entityLogical2Group | 1.3.6.1.2.1.47.2.2.5 | Logical entity group v2. | ||
| entityMappingGroup | 1.3.6.1.2.1.47.2.2.6 | Entity mapping objects. | ||
| entityGeneralGroup | 1.3.6.1.2.1.47.2.2.7 | General entity objects. |
FAQ
What is ENTITY-MIB used for in a chassis-based router or switch monitoring setup?
It's the vendor-neutral IETF standard (RFC 6933) inventory model that represents a device's physical and logical components -- chassis, modules, power supplies, fans, sensors, ports -- as entries in entPhysicalTable, with fields like entPhysicalDescr, entPhysicalVendorType, entPhysicalContainedIn, and entPhysicalClass. It lets an operator enumerate every physical component in a chassis, confirm which slot a module sits in, and verify hardware, firmware (entPhysicalHardwareRev, entPhysicalFirmwareRev), and software revision levels are consistent across redundant components like fans, power supplies, or line cards.
Why do other hardware-monitoring MIBs reference ENTITY-MIB?
Because ENTITY-MIB's entPhysicalIndex is the common key many vendor-specific environment, power, and sensor MIBs use to associate their own readings with a specific physical component, making ENTITY-MIB a foundational dependency for hardware-health monitoring across virtually any modular router or switch.
RFC description
Physical entity MIB for managing hardware components, modules, and their relationships in networked devices (RFC 4133).
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