RFC 4133
Entity MIB (Version 3)
Entity MIB (Version 3) 🎀
Part 1 of 12 🧚 more coming, so stay tuned bestie!
Okay so this is RFC 4133 💖, the Entity MIB (Version 3), and it's from the Network Working Group. Alastair Bierman and K. McCloghrie wrote it at Cisco Systems, Inc., it's on the Standards Track, and it's dated August 2005 ✨. It obsoletes RFC 2737 🦋, which was version 2 of this MIB, so if you see the old one floating around, this is the new and improved version 💅.
Status of This Memo
This document is an Internet standards track protocol for the Internet community 🌸, and it's basically asking everyone to talk about it and suggest improvements 🫶. If you want to know where it stands in the standardization process, check the current edition of the "Internet Official Protocol Standards" (STD 1) 📚. Distribution of this memo is unlimited, so share it with all your friends 💜.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community 🧚. The main vibe is managing multiple logical and physical entities that are all managed by a single SNMP agent 🔥. This document specifies version 3 of the Entity MIB, which obsoletes version 2 (RFC 2737) 👑.
Table of Contents
1. The SNMP Management Framework ...................................3
2. Overview ........................................................3
2.1. Terms ......................................................4
2.2. Relationship to Community Strings ..........................5
2.3. Relationship to SNMP Contexts ..............................5
2.4. Relationship to Proxy Mechanisms ...........................6
2.5. Relationship to a Chassis MIB ..............................6
2.6. Relationship to the Interfaces MIB .........................6
2.7. Relationship to the Other MIBs .............................7
2.8. Relationship to Naming Scopes ..............................7
2.9. Multiple Instances of the Entity MIB .......................7
2.10. Re-Configuration of Entities ..............................8
2.11. Textual Convention Change .................................8
2.12. MIB Structure .............................................8
2.12.1. entityPhysical Group ..............................9
2.12.2. entityLogical Group ..............................11
2.12.3. entityMapping Group ..............................11
2.12.4. entityGeneral Group ..............................12
2.12.5. entityNotifications Group ........................12
2.13. Multiple Agents ..........................................12
2.14. Changes Since RFC 2037 ...................................12
2.14.1. Textual Conventions ..............................12
2.14.2. New entPhysicalTable Objects .....................13
2.14.3. New entLogicalTable Objects ......................13
2.14.4. Bug Fixes ........................................13
2.15. Changes Since RFC 2737 ...................................13
2.15.1. Textual Conventions ..............................13
2.15.2. New Objects ......................................14
2.15.3. Bug Fixes ........................................14
3. Definitions ....................................................14
4. Usage Examples .................................................44
4.1. Router/Bridge .............................................44
4.2. Repeaters .................................................50
5. Security Considerations ........................................57
6. IANA Considerations ............................................58
7. Acknowledgements ...............................................59
8. References .....................................................59
8.1. Normative References ......................................59
8.2. Informative References ....................................591. The SNMP Management Framework 🌈
If you want the full scoop on the documents that describe the current Internet-Standard Management Framework, go check out section 7 of RFC 3410 [RFC3410] 📖.
Okay, so managed objects are accessed via a virtual information store called the Management Information Base, or MIB 💅. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP) 🦋. Objects in the MIB are defined using the mechanisms in the Structure of Management Information (SMI) 🎀. This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580] 🧚.
2. Overview ✨
Here's the thing: there's a real need for a standardized way to represent a single agent that supports multiple instances of one MIB 💖. This is already true for at least 3 standard MIBs, and it's only going to become true for more and more MIBs as time goes on 🔥. For example:
- multiple instances of a bridge supported within a single device that has a single agent;
- multiple repeaters supported by a single agent;
- multiple OSPF backbone areas, each operating as part of its own Autonomous System, and each identified by the same area-id (e.g.,
0.0.0.0), supported inside a single router with one agent.
The single agent in each of these cases implies a relationship that binds these entities together 🫶. Effectively, there's some "overall" physical entity that houses everything managed by that one agent, so there are multiple "logical" entities living inside a single physical entity 🏠. Sometimes the overall physical entity contains multiple (smaller) physical entities, and each logical entity is tied to a particular physical entity 🌸. Other times the overall physical entity is a "compound" of multiple physical entities, like a stack of stackable hubs 🥞.
So what we need is a way to figure out exactly which logical entities the agent manages (with some version of SNMP) so you can talk to the agent about a particular logical entity 🕵️♀️. When different logical entities are associated with different physical entities inside the overall physical entity, it's also handy to use that info to tell the logical entities apart 💜.
In these situations, there's no need for varbinds for multiple logical entities to be referenced in the same SNMP message (although that might be useful in the future) 🙈. Instead, it's enough, and sometimes even better, to have the context or community in the message identify the logical entity the varbinds apply to ✨.
Version 2 of this MIB addresses new requirements that popped up after the first Entity MIB came out (RFC 2037 [RFC2037]) 🍓. There's a need for a standardized way to provide non-volatile, administratively-assigned identifiers for physical components represented in the Entity MIB 🔐. There's also a need to line the Entity MIB up with the SNMPv3 administrative framework (STD 62, RFC 3411 [RFC3411]) 🎀. And implementation experience has shown that extra physical component attributes are also desirable 🌈.
Version 3 of this MIB addresses new requirements that showed up after the second Entity MIB (RFC 2737 [RFC2737]) 🧚. We need to identify physical entities that are central processing units (CPUs) 🧠, and we need a textual convention that identifies an entPhysicalIndex value or zero, where zero has application-specific semantics 🔢. Two new objects were also added to the entPhysicalTable to identify the manufacturing date and provide additional URIs for a particular physical entity 📅🔗.
2.1. Terms
Some new terms are used throughout this document 📝:
- Naming Scope: A "naming scope" represents the set of information that may be potentially accessed through a single SNMP operation. All instances within the naming scope share the same unique identifier space. For SNMPv1, a naming scope is identified by the value of the associated
'entLogicalCommunity'instance. For SNMPv3, the term'context'is used instead of'naming scope'. The complete definition of an SNMP context can be found in section 3.3.1 of RFC 3411 [RFC3411] 💫. - Multi-Scoped Object: A MIB object, for which identical instance values identify different managed information in different naming scopes, is called a "multi-scoped" MIB object 🦋.
- Single-Scoped Object: A MIB object, for which identical instance values identify the same managed information in different naming scopes, is called a "single-scoped" MIB object 🌸.
- Logical Entity: A managed system contains one or more logical entities, each represented by at most one instantiation of each of a particular set of MIB objects. A set of management functions is associated with each logical entity. Examples of logical entities include routers, bridges, print-servers, etc. 🖨️
- Physical Entity: A "physical entity" or "physical component" represents an identifiable physical resource within a managed system. Zero or more logical entities may utilize a physical resource at any given time. Determining which physical components are represented by an agent in the EntPhysicalTable is an implementation-specific matter 🛠️. Typically, physical resources (e.g., communications ports, backplanes, sensors, daughter-cards, power supplies, the overall chassis), which can be managed via functions associated with one or more logical entities, are included in the MIB 🔌.
- Containment Tree: Each physical component may be modeled as 'contained' within another physical component. A "containment-tree" is the conceptual sequence of entPhysicalIndex values that uniquely specifies the exact physical location of a physical component within the managed system. It is generated by 'following and recording' each 'entPhysicalContainedIn' instance 'up the tree towards the root', until a value of zero indicating no further containment is found 🌳.
2.2. Relationship to Community Strings
For community-based SNMP, telling logical entities apart is one purpose of the community string (RFC 1157 [RFC1157]), though it's not the only one 🔑. This is handled by representing each community string as a logical entity 💖.
Heads up: different logical entities can share the same naming scope and therefore the same values of entLogicalCommunity 🧐. This is possible as long as they don't need the same instance of a MIB object to represent different managed information ✨.
2.3. Relationship to SNMP Contexts
Version 2 of the Entity MIB supports associating SNMPv3 contexts with logical entities 🎀. Two new MIB objects, which define an SnmpEngineID and ContextName pair, are used together to identify an SNMP context associated with a logical entity 🧩. This context can be used (in conjunction with the entLogicalTAddress and entLogicalTDomain MIB objects) to send SNMPv3 messages on behalf of a particular logical entity 📨💅.
2.4. Relationship to Proxy Mechanisms 🦋
okay so the Entity MIB is built for finding out what functional components a device has 🔍 but it does NOT show the administrative relationships between logical entities. no table in the Entity MIB tells an NMS whether a MIB instance in a different naming scope is running locally or remotely (say, through some proxy setup) 🙈 you can't figure that out by looking at the Entity MIB objects alone. bestie, that's a whole vibe check 💀
the working group isn't really trying to manage administrative framework functions right now ✨ this is a brand new area, so they might come back to it once people have some real-world experience with the Entity MIB 🌸
also, for community-based versions of SNMP, a network admin will probably be able to link community strings to naming scopes that use proprietary mechanisms, just as a matter of configuration ⚙️ there are no mechanisms in this MIB for managing naming scopes though, so that part is on the config side 💅
2.5. Relationship to a Chassis MIB 🎀
some of y'all might remember that an earlier IETF working group tried to define a Chassis MIB 😭 they never reached consensus, and it might be because the scope was just way too broad 💀 so this MIB is NOT trying to be a "Chassis MIB replacement" 🙅♀️ and it's not supposed to hold every single bit of info someone might need to manage a "chassis" either.
BUT, the entities this MIB represents might totally live inside a chassis 🧚 so yeah, they can overlap, just not in the "replace everything" way.
2.6. Relationship to the Interfaces MIB 🔌
the Entity MIB has a mapping table that links physical components to their 'external values' (like ifIndex) within a given naming scope 💖 you can use that table to figure out the physical location of each interface in the ifTable (RFC 2863 [RFC2863]) 📍 ifIndex values in different contexts aren't related to each other though, so the interface-to-physical-component associations only make sense relative to the same logical entity inside the agent 🫶
also! the Entity MIB has 'entPhysicalName' and 'entPhysicalAlias' objects, which kind of approximate the 'ifName' and 'ifAlias' objects from the Interfaces MIB [RFC2863] ✨ (respectively, lol). and they work for all types of physical components, not just interfaces 🌈
2.7. Relationship to the Other MIBs 🍓
the Entity MIB also has a mapping table, but this one links physical components to identifiers from other standard MIBs 🧩 for example, you can combine this table with the physical mapping table to find the physical location of each repeater port in the rptrPortTable, or each interface in the ifTable 🔥
2.8. Relationship to Naming Scopes 👑
okay this one is a little messy, ngl 😵💫 there's some question about which MIB objects can be returned within a given naming scope. MIB objects that aren't multi-scoped inside a managed system will probably ignore context info when implemented 🙈 so those objects will likely show up in all naming scopes, not just the 'default' naming scope or the SNMPv3 default context 💜
for example, a community string used to get at the management info for logical device 'bridge2' might give access to all the non-bridge objects in the 'default' naming scope, plus a second instance of the Bridge MIB (RFC 1493 [RFC1493]) 🌸
how an agent isolates single-scoped MIB objects is up to the implementation 🛠️ an agent might want to limit what gets returned in a naming scope to only the multi-scoped objects there (like the system group and the Bridge MIB) 🎀 in that case, all the single-scoped management info would sit in one shared naming scope (like 'default'), and that scope could still have some multi-scoped objects too (like the system group) ✨
2.9. Multiple Instances of the Entity MIB 🧚
it's totally possible for more than one agent to exist in a managed system 🫧 when that happens, an NMS might see multiple instances of the Entity MIB (all representing the same managed objects) 👀
so here's the tea: to keep agent implementations simpler, multiple instances of the Entity MIB don't have to match each other, or even be consistent 💅 an NMS can try to 'align' what different agents return by looking at the columns of each table, but vendor-specific identifiers (and especially index values) will probably be different 🙃 and each agent might be managing a different slice of the whole chassis too 🧩
when one agent represents all of a physically-modular device, the entry where entPhysicalContainedIn has the value zero would likely have 'chassis' as its entPhysicalClass 🏗️ on the flip side, if an agent lives on a module and only represents the physical entities on that module (not the ones on other modules), the entry where entPhysicalContainedIn has the value zero would likely have 'module' as its entPhysicalClass 🎀
an agent implementing the entLogicalTable doesn't have to include info about logical entities that are mainly managed by other agents 🙅♀️ the entLogicalTAddress and entLogicalTDomain objects in the entLogicalTable are there to support an historical multiplexing mechanism, NOT to identify other SNMP agents 💀
also worth knowing: the Entity MIB is a single-scoped MIB, even if an agent represents it in different naming scopes 🔒
2.10. Re-Configuration of Entities 🔧
most of the MIB objects in this MIB have, at most, a read-only MAX-ACCESS clause 👀 that was a deliberate choice by the working group to keep this MIB's scope tight 💅 the second version of the Entity MIB does let a network admin configure some common attributes of physical components though ✨
2.11. Textual Convention Change 📝
version 1 of the Entity MIB had three MIB objects using the (now obsolete) DisplayString textual convention 🥲 in version 2, the syntax for those objects got updated to use the (now preferred) SnmpAdminString textual convention 💖
the working group knows this change isn't strictly supported by SMIv2 😬 but they judged that deprecating the old objects and defining new ones would hurt backward compatibility and interoperability even more, given what these objects actually do 🫶
2.12. MIB Structure 🧩
the Entity MIB has five groups of MIB objects:
- entityPhysical group Describes the physical entities managed by a single agent.
- entityLogical group Describes the logical entities managed by a single agent.
- entityMapping group Describes the associations between the physical entities, logical entities, interfaces, and non-interface ports managed by a single agent.
- entityGeneral group Describes general system attributes shared by potentially all types of entities managed by a single agent.
- entityNotifications group Contains status indication notifications.
2.12.1. entityPhysical Group 🌈
this group has a single table for identifying physical system components, called the entPhysicalTable 📋
the entPhysicalTable has one row per physical entity, and it must always have at least one row for an "overall" physical entity 👑 that row should have an entPhysicalClass value of 'stack(11)', 'chassis(3)' or 'module(9)' 🏗️
each row is indexed by an arbitrary, small integer, and holds a description and type for the physical entity 🔢 it can also optionally hold the index number of another entPhysicalEntry, which shows a containment relationship between the two 🫧
version 2 of the Entity MIB adds more MIB objects for each physical entity 💅 some common read-only attributes were added, plus three writable string objects ✨
- entPhysicalAlias This string can be used by an NMS as a non-volatile identifier for the physical component. Maintaining a non-volatile string for every physical component represented in the entPhysicalTable can be costly and unnecessary. An agent may algorithmically generate 'entPhysicalAlias' strings for particular entries (e.g., based on the entPhysicalClass value).
- entPhysicalAssetID This string is provided to store a user-specific asset identifier for removable physical components. In order to reduce the non- volatile storage needed by a particular agent, a network administrator should only assign asset identifiers to physical entities that are field-replaceable (i.e., not permanently contained within another physical entity).
- entPhysicalSerialNum This string is provided to store a vendor-specific serial number string for physical components. This writable object is used when an agent cannot identify the serial numbers of all installed physical entities, and a network administrator wishes to configure the non-volatile serial number strings manually (via an NMS application).
version 3 of the Entity MIB adds two more MIB objects for each physical entity 🎁
- entPhysicalMfgDate This object contains the date of manufacturing of the managed entity. If the manufacturing date is unknown or not supported the object is not instantiated. The special value '0000000000000000'H may also be returned in this case.
- entPhysicalUris This object provides additional identification information about the physical entity.
This object contains one or more Uniform Resource Identifiers (URIs) and, therefore, the syntax of this object must conform to RFC 3986 [RFC3986] section 2. Uniform Resource Names (URNs), RFC 3406 [RFC3406], are resource identifiers with the specific requirements for enabling location independent identification of a resource, as well as longevity of reference. URNs are part of the larger URI family with the specific goal of providing persistent naming of resources. URI schemes and URN name spaces are registered by IANA (see http://www.iana.org/assignments/uri-schemes and http://www.iana.org/assignments/urn-namespaces).
For example, the entPhysicalUris object may be used to encode a URI containing a Common Language Equipment Identifier (CLEI) URN for the managed physical entity. The URN name space for CLEIs is defined in [RFC4152], and the CLEI format is defined in [T1.213][T1.213a]. For example, an entPhysicalUris instance may have the value of
URN:CLEI:D4CE18B7AA[RFC3986] and [RFC4152] identify this as a URI in the CLEI URN name space. The specific CLEI code, D4CE18B7AA, is based on the example provided in [T1.213a].
Multiple URIs may be present and are separated by white space characters. Leading and trailing white space characters are ignored.
If no additional identification information is known about the physical entity or supported, the object is not instantiated.
2.12.2. entityLogical Group 🧚
Okay bestie, this group is all about one table: the entLogicalTable 💅 It's where we identify logical entities.
Each row is indexed by an arbitrary, small integer, and holds a name, a description, and a type for the logical entity. It also has the info you need to reach the MIB information for that logical entity. That covers SNMP versions that use a community name (with some form of implied context representation), and SNMP versions that use the SNMP ARCH [RFC3411] method of context identification 🔑
If an agent represents multiple logical entities with this MIB, then this group must be implemented for all logical entities known to the agent. No skipping, periodt 💖
If an agent represents a single logical entity, or multiple logical entities within a single naming scope, then implementation of this group may be omitted by the agent. Lowkey simpler for those agents 🫶
2.12.3. entityMapping Group 🦋
This group has three tables that link different system components together 🔗
- entLPMappingTable: This table contains mappings between
entLogicalIndexvalues (logical entities) andentPhysicalIndexvalues (the physical components supporting that entity). A logical entity can map to more than one physical component, and more than one logical entity can map to (share) the same physical component. If an agent represents a single logical entity, or multiple logical entities within a single naming scope, then implementation of this table may be omitted by the agent. 🌸 - entAliasMappingTable: This table contains mappings between
entLogicalIndex,entPhysicalIndexpairs, and 'alias' object identifier values. This lets resources managed with other MIBs (e.g., repeater ports, bridge ports, physical and logical interfaces) be identified in the physical entity hierarchy. Note that each alias identifier is only relevant in a particular naming scope. If an agent represents a single logical entity, or multiple logical entities within a single naming scope, then implementation of this table may be omitted by the agent. ✨ - entPhysicalContainsTable: This table contains simple mappings between 'entPhysicalContainedIn' values for each container/'containee' relationship in the managed system. The indexing of this table lets an NMS quickly discover the 'entPhysicalIndex' values for all children of a given physical entity. Main character energy for NMS fr fr 🎀
2.12.4. entityGeneral Group ⭐
This group holds general info that relates to the other object groups.
Right now, the entGeneral group has just one scalar object, entLastChangeTime. It represents the value of sysUptime when any part of the Entity MIB configuration last changed. Iconic, simple, done 🍓
2.12.5. entityNotifications Group 🔔
This group has the notification definitions for the overall status of the Entity MIB instantiation.
2.13. Multiple Agents 🌈
Okay so, a big reason this MIB exists is to represent the multiple logical entities one agent supports. But there's another goal too: representing multiple logical entities supported by multiple agents, all inside the same "overall" physical entity. The SNMP architecture kind of assumes that a network management station doesn't need to care how many agents there are, so that fits 🧚
Here's the tea though. There's no agreement yet on how much cooperation agent implementations should be expecting from each other. So multiple agents within the same managed system are free to implement the Entity MIB independently. (For more info, check Section 2.9, "Multiple Instances of the Entity MIB" 💜)
2.14. Changes Since RFC 2037 🎀
2.14.1. Textual Conventions 💅
The PhysicalClass TC text got clarified, and there's a new enumeration to support 'stackable' components. The SnmpEngineIdOrNone TC was added to support SNMPv3 🦋
2.14.2. New entPhysicalTable Objects ✨
The entPhysicalHardwareRev, entPhysicalFirmwareRev, and entPhysicalSoftwareRev objects were added for revision identification.
The entPhysicalSerialNum, entPhysicalMfgName, entPhysicalModelName, and entPhysicalIsFru objects were added for better vendor identification of physical components. If the agent can't identify this info, then a management station can set the entPhysicalSerialNum object 🫶
The entPhysicalAlias and entPhysicalAssetID objects were added for better user component identification. They're meant to be set by a management station, and the agent should preserve them across restarts 🔥
2.14.3. New entLogicalTable Objects 🧚
The entLogicalContextEngineID and entLogicalContextName objects were added to provide an SNMP context for SNMPv3 access on behalf of a logical entity 🔑
2.14.4. Bug Fixes 🙈
A bug got fixed in the entLogicalCommunity object. The subrange was incorrect (1..255) and is now (0..255). The description clause got clarified too. This object is now deprecated 💀
The entLastChangeTime object description was changed to generalize the events that cause an update to the last change timestamp 🌸
The syntax changed from DisplayString to SnmpAdminString for the entPhysicalDescr, entPhysicalName, and entLogicalDescr objects 💖
2.15. Changes Since RFC 2737 🌈
2.15.1. Textual Conventions 🦋
The PhysicalIndexOrZero TC was added so objects can reference an entPhysicalIndex value or zero. The PhysicalClass TC got extended with a new enumeration for central processing units 👑
2.15.2. New Objects ⭐
The entPhysicalMfgDate object was added to the entPhysicalTable to provide the date of manufacturing for the managed entity 🍓
The entPhysicalUris object was added to the entPhysicalTable to provide extra identification info about the physical entity, such as a Common Language Equipment Identifier (CLEI) URN 🎀
2.15.3. Bug Fixes 💅
The syntax changed from INTEGER to Integer32 for the entPhysicalParentRelPos, entLogicalIndex, and entAliasLogicalIndexOrZero objects. It also changed from INTEGER to PhysicalIndexOrZero for the entPhysicalContainedIn object 🙈
3. Definitions ✨
ENTITY-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, mib-2, NOTIFICATION-TYPE,
Integer32
FROM SNMPv2-SMI
TDomain, TAddress, TEXTUAL-CONVENTION,
AutonomousType, RowPointer, TimeStamp, TruthValue,
DateAndTime
FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
FROM SNMPv2-CONF
SnmpAdminString
FROM SNMP-FRAMEWORK-MIB;
entityMIB MODULE-IDENTITY
LAST-UPDATED "200508100000Z"
ORGANIZATION "IETF ENTMIB Working Group"
CONTACT-INFO
" WG E-mail: entmib@ietf.org
Mailing list subscription info:
http://www.ietf.org/mailman/listinfo/entmib
Andy Bierman
ietf@andybierman.com
Keith McCloghrie
Cisco Systems Inc.
170 West Tasman Drive
San Jose, CA 95134
+1 408-526-5260
kzm@cisco.com"
DESCRIPTION
"The MIB module for representing multiple logical
entities supported by a single SNMP agent.
Copyright (C) The Internet Society (2005). This
version of this MIB module is part of RFC 4133; see
the RFC itself for full legal notices."
REVISION "200508100000Z"
DESCRIPTION
"Initial Version of Entity MIB (Version 3).
This revision obsoletes RFC 2737.
Additions:
- cpu(12) enumeration added to PhysicalClass TC
- DISPLAY-HINT clause to PhysicalIndex TC
- PhysicalIndexOrZero TC
- entPhysicalMfgDate object
- entPhysicalUris object
Changes:
- entPhysicalContainedIn SYNTAX changed from
INTEGER to PhysicalIndexOrZero
This version published as RFC 4133."
REVISION "199912070000Z"
DESCRIPTION
"Initial Version of Entity MIB (Version 2).
This revision obsoletes RFC 2037.
This version published as RFC 2737."
REVISION "199610310000Z"
DESCRIPTION
"Initial version (version 1), published as
RFC 2037."
::= { mib-2 47 }
entityMIBObjects OBJECT IDENTIFIER ::= { entityMIB 1 }
-- MIB contains four groups
entityPhysical OBJECT IDENTIFIER ::= { entityMIBObjects 1 }
entityLogical OBJECT IDENTIFIER ::= { entityMIBObjects 2 }
entityMapping OBJECT IDENTIFIER ::= { entityMIBObjects 3 }
entityGeneral OBJECT IDENTIFIER ::= { entityMIBObjects 4 }
-- Textual Conventions
PhysicalIndex ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"An arbitrary value that uniquely identifies the physical
entity. The value should be a small, positive integer.
Index values for different physical entities are not
necessarily contiguous."
SYNTAX Integer32 (1..2147483647)
PhysicalIndexOrZero ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"This textual convention is an extension of the
PhysicalIndex convention, which defines a greater than zero
value used to identify a physical entity. This extension
permits the additional value of zero. The semantics of the
value zero are object-specific and must, therefore, be
defined as part of the description of any object that uses
this syntax. Examples of the usage of this extension are
situations where none or all physical entities need to be
referenced."
SYNTAX Integer32 (0..2147483647)Okay bestie, picking up right where we left off 💖 The textual conventions come first, starting with PhysicalClass, which is basically the "what kind of hardware is this?" enum 🔌✨
PhysicalClass ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"An enumerated value which provides an indication of the
general hardware type of a particular physical entity.
There are no restrictions as to the number of
entPhysicalEntries of each entPhysicalClass, which must be
instantiated by an agent.
The enumeration 'other' is applicable if the physical entity
class is known, but does not match any of the supported
values.
The enumeration 'unknown' is applicable if the physical
entity class is unknown to the agent.
The enumeration 'chassis' is applicable if the physical
entity class is an overall container for networking
equipment. Any class of physical entity, except a stack,
may be contained within a chassis; and a chassis may only
be contained within a stack.
The enumeration 'backplane' is applicable if the physical
entity 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 agent may model a
backplane as a single physical entity, which is actually
implemented as multiple discrete physical components (within
a chassis or stack).
The enumeration 'container' is applicable if the physical
entity 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
entities should be modeled within a container entity, such
as field-replaceable modules, fans, or power supplies. Note
that all known containers should be modeled by the agent,
including empty containers.
The enumeration 'powerSupply' is applicable if the physical
entity class is a power-supplying component.
The enumeration 'fan' is applicable if the physical entity
class is a fan or other heat-reduction component.
The enumeration 'sensor' is applicable if the physical
entity class is some sort of sensor, such as a temperature
sensor within a router chassis.
The enumeration 'module' is applicable if the physical
entity class is some sort of self-contained sub-system. If
the enumeration 'module' is removable, then it should be
modeled within a container entity, otherwise it should be
modeled directly within another physical entity (e.g., a
chassis or another module).
The enumeration 'port' is applicable if the physical entity
class is some sort of networking port, capable of receiving
and/or transmitting networking traffic.
The enumeration 'stack' is applicable if the physical entity
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 may in
fact be comprised of multiple interconnect cables. A stack
should not be modeled within any other physical entities,
but a stack may be contained within another stack. Only
chassis entities should be contained within a stack.
The enumeration 'cpu' is applicable if the physical entity
class is some sort of central processing unit."
SYNTAX INTEGER {
other(1),
unknown(2),
chassis(3),
backplane(4),
container(5), -- e.g., chassis slot or daughter-card holder
powerSupply(6),
fan(7),
sensor(8),
module(9), -- e.g., plug-in card or daughter-card
port(10),
stack(11), -- e.g., stack of multiple chassis entities
cpu(12)
}So the vibe is: there's no limit on how many entPhysicalEntries of each class an agent has to instantiate 🫶 The SYNTAX lists twelve values, from other(1) all the way to cpu(12). Quick highlights:
- other is for "I know what it is, but it's not on the list" 🤷♀️
- unknown is for "the agent has no clue" 💀
- chassis is the big overall container, and only a stack can hold it 🏠
- container is the slot-holder energy, and every known container should be modeled, even the empty ones 🍓
- stack is the super-container that groups chassis, and it's not supposed to live inside any other physical entity 👑
Next up is SnmpEngineIdOrNone, which is giving "optional but make it make sense" 🧚
SnmpEngineIdOrNone ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"A specially formatted SnmpEngineID string for use with the
Entity MIB.
If an instance of an object of SYNTAX SnmpEngineIdOrNone has
a non-zero length, then the object encoding and semantics
are defined by the SnmpEngineID textual convention (see STD
62, RFC 3411 [RFC3411]).
If an instance of an object of SYNTAX SnmpEngineIdOrNone
contains a zero-length string, then no appropriate
SnmpEngineID is associated with the logical entity (i.e.,
SNMPv3 is not supported)."
SYNTAX OCTET STRING (SIZE(0..32)) -- empty string or SnmpEngineIDBasically, a non-zero length means the encoding and semantics come from the SnmpEngineID textual convention in [RFC3411] 🔑, and a zero-length string means there's no SnmpEngineID for that logical entity, aka SNMPv3 isn't supported 🙈
Now the big one: the Physical Entity Table 📋✨
-- The Physical Entity Table
entPhysicalTable OBJECT-TYPE
SYNTAX SEQUENCE OF EntPhysicalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table contains one row per physical entity. There is
always at least one row for an 'overall' physical entity."
::= { entityPhysical 1 }
entPhysicalEntry OBJECT-TYPE
SYNTAX EntPhysicalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular physical entity.
Each entry provides objects (entPhysicalDescr,
entPhysicalVendorType, and entPhysicalClass) to help an NMS
identify and characterize the entry, and objects
(entPhysicalContainedIn and entPhysicalParentRelPos) to help
an NMS relate the particular entry to other entries in this
table."
INDEX { entPhysicalIndex }
::= { entPhysicalTable 1 }
EntPhysicalEntry ::= SEQUENCE {
entPhysicalIndex PhysicalIndex,
entPhysicalDescr SnmpAdminString,
entPhysicalVendorType AutonomousType,
entPhysicalContainedIn PhysicalIndexOrZero,
entPhysicalClass PhysicalClass,
entPhysicalParentRelPos Integer32,
entPhysicalName SnmpAdminString,
entPhysicalHardwareRev SnmpAdminString,
entPhysicalFirmwareRev SnmpAdminString,
entPhysicalSoftwareRev SnmpAdminString,
entPhysicalSerialNum SnmpAdminString,
entPhysicalMfgName SnmpAdminString,
entPhysicalModelName SnmpAdminString,
entPhysicalAlias SnmpAdminString,
entPhysicalAssetID SnmpAdminString,
entPhysicalIsFRU TruthValue,
entPhysicalMfgDate DateAndTime,
entPhysicalUris OCTET STRING
}The table has one row per physical entity, and there's always at least one row for the "overall" entity 🌈 Each row is indexed by entPhysicalIndex, and the entry's job is to help an NMS figure out what something is and how it connects to everything else 🦋
Now the individual columns, starting with the index 🔢
entPhysicalIndex OBJECT-TYPE
SYNTAX PhysicalIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The index for this entry."
::= { entPhysicalEntry 1 }Next is entPhysicalDescr, which should hold the manufacturer's name for the entity and be distinct for each version or model 💅
entPhysicalDescr OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A textual description of physical entity. This object
should contain a string that identifies the manufacturer's
name for the physical entity, and should be set to a
distinct value for each version or model of the physical
entity."
::= { entPhysicalEntry 2 }Then entPhysicalVendorType, which is the vendor-specific hardware type. It's not the same as MIB-II's sysObjectID, so don't mix them up 🙅♀️
entPhysicalVendorType OBJECT-TYPE
SYNTAX AutonomousType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An indication of the vendor-specific hardware type of the
physical entity. Note that this is different from the
definition of MIB-II's sysObjectID.
An agent should set this object to an enterprise-specific
registration identifier value indicating the specific
equipment type in detail. The associated instance of
entPhysicalClass is used to indicate the general type of
hardware device.
If no vendor-specific registration identifier exists for
this physical entity, or the value is unknown by this agent,
then the value { 0 0 } is returned."
::= { entPhysicalEntry 3 }The fallback here is { 0 0 } if there's no registration identifier or the agent doesn't know it 🫠 And the general type? That's what entPhysicalClass is for, so the two columns work as a team 👯♀️
Next is entPhysicalContainedIn, which is the "who's my parent" column 👑
entPhysicalContainedIn OBJECT-TYPE
SYNTAX PhysicalIndexOrZero
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of entPhysicalIndex for the physical entity which
'contains' this physical entity. A value of zero indicates
this physical entity is not contained in any other physical
entity. Note that the set of 'containment' relationships
define a strict hierarchy; that is, recursion is not
allowed.
In the event that a physical entity is contained by more
than one physical entity (e.g., double-wide modules), this
object should identify the containing entity with the lowest
value of entPhysicalIndex."
::= { entPhysicalEntry 4 }Zero means "I'm not inside anything," and the containment relationships form a strict hierarchy, so no recursion allowed 🙅♀️ If something is contained by more than one entity (think double-wide modules 🎀), this column should point to the container with the lowest entPhysicalIndex.
Last but not least, entPhysicalClass 🌸
entPhysicalClass OBJECT-TYPE
SYNTAX PhysicalClass
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An indication of the general hardware type of the physical
entity.
An agent should set this object to the standard enumeration
value that most accurately indicates the general class of
the physical entity, or the primary class if there is more
than one entity.
If no appropriate standard registration identifier exists
for this physical entity, then the value 'other(1)' is
returned. If the value is unknown by this agent, then the
value 'unknown(2)' is returned."
::= { entPhysicalEntry 5 }This one is the general-hardware-type column, and the agent should pick the standard enum value that fits best 💖 If there's no appropriate standard value, it returns other(1), and if the agent doesn't know the class at all, it returns unknown(2) ✨
entPhysicalParentRelPos OBJECT-TYPE SYNTAX Integer32 (-1..2147483647) MAX-ACCESS read-only STATUS current DESCRIPTION "An indication of the relative position of this 'child' component among all its 'sibling' components. Sibling components are defined as entPhysicalEntries that share the same instance values of each of the entPhysicalContainedIn and entPhysicalClass objects.
An NMS can use this object to identify the relative ordering for all sibling components of a particular parent (identified by the entPhysicalContainedIn instance in each sibling entry).
If possible, this value should match any external labeling of the physical component. For example, for a container (e.g., card slot) labeled as 'slot #3', entPhysicalParentRelPos should have the value '3'. Note that the entPhysicalEntry for the module plugged in slot 3 should have an entPhysicalParentRelPos value of '1'.
If the physical position of this component does not match any external numbering or clearly visible ordering, then user documentation or other external reference material should be used to determine the parent-relative position. If this is not possible, then the agent should assign a consistent (but possibly arbitrary) ordering to a given set of 'sibling' components, perhaps based on internal representation of the components.
If the agent cannot determine the parent-relative position for some reason, or if the associated value of entPhysicalContainedIn is '0', then the value '-1' is returned. Otherwise, a non-negative integer is returned, indicating the parent-relative position of this physical entity.
Parent-relative ordering normally starts from '1' and continues to 'N', where 'N' represents the highest positioned child entity. However, if the physical entities (e.g., slots) are labeled from a starting position of zero, then the first sibling should be associated with an entPhysicalParentRelPos value of '0'. Note that this ordering may be sparse or dense, depending on agent implementation.
The actual values returned are not globally meaningful, as each 'parent' component may use different numbering algorithms. The ordering is only meaningful among siblings of the same parent component.
The agent should retain parent-relative position values across reboots, either through algorithmic assignment or use of non-volatile storage." ::= { entPhysicalEntry 6 }
entPhysicalName OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current DESCRIPTION "The textual name of the physical entity. The value of this object should be the name of the component as assigned by the local device and should be suitable for use in commands entered at the device's console'. This might be a text name (e.g., console') or a simple component number (e.g., port or module number, such as `1'), depending on the physical component naming syntax of the device.
If there is no local name, or if this object is otherwise not applicable, then this object contains a zero-length string.
Note that the value of entPhysicalName for two physical entities will be the same in the event that the console interface does not distinguish between them, e.g., slot-1 and the card in slot-1." ::= { entPhysicalEntry 7 }
entPhysicalHardwareRev OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current DESCRIPTION "The vendor-specific hardware revision string for the physical entity. The preferred value is the hardware revision identifier actually printed on the component itself (if present).
Note that if revision information is stored internally in a non-printable (e.g., binary) format, then the agent must convert such information to a printable format, in an implementation-specific manner.
If no specific hardware revision string is associated with the physical component, or if this information is unknown to the agent, then this object will contain a zero-length string." ::= { entPhysicalEntry 8 }
entPhysicalFirmwareRev OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current DESCRIPTION "The vendor-specific firmware revision string for the physical entity.
Note that if revision information is stored internally in a non-printable (e.g., binary) format, then the agent must convert such information to a printable format, in an implementation-specific manner.
If no specific firmware programs are associated with the physical component, or if this information is unknown to the agent, then this object will contain a zero-length string." ::= { entPhysicalEntry 9 }
entPhysicalSoftwareRev OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current DESCRIPTION "The vendor-specific software revision string for the physical entity.
Note that if revision information is stored internally in a non-printable (e.g., binary) format, then the agent must convert such information to a printable format, in an implementation-specific manner.
If no specific software programs are associated with the physical component, or if this information is unknown to the agent, then this object will contain a zero-length string." ::= { entPhysicalEntry 10 }
entPhysicalSerialNum OBJECT-TYPE SYNTAX SnmpAdminString (SIZE (0..32)) MAX-ACCESS read-write STATUS current DESCRIPTION "The vendor-specific serial number string for the physical entity. The preferred value is the serial number string actually printed on the component itself (if present).
On the first instantiation of an physical entity, the value of entPhysicalSerialNum associated with that entity is set to the correct vendor-assigned serial number, if this information is available to the agent. If a serial number is unknown or non-existent, the entPhysicalSerialNum will be set to a zero-length string instead.
Note that implementations that can correctly identify the serial numbers of all installed physical entities do not need to provide write access to the entPhysicalSerialNum object. Agents which cannot provide non-volatile storage for the entPhysicalSerialNum strings are not required to implement write access for this object.
Not every physical component will have a serial number, or even need one. Physical entities for which the associated value of the entPhysicalIsFRU object is equal to 'false(2)' (e.g., the repeater ports within a repeater module), do not need their own unique serial number. An agent does not have to provide write access for such entities, and may return a zero-length string.
If write access is implemented for an instance of entPhysicalSerialNum, and a value is written into the instance, the agent must retain the supplied value in the entPhysicalSerialNum instance (associated with the same physical entity) for as long as that entity remains instantiated. This includes instantiations across all re-initializations/reboots of the network management system, including those resulting in a change of the physical entity's entPhysicalIndex value." ::= { entPhysicalEntry 11 }
entPhysicalMfgName OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current 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 entPhysicalModelName, entPhysicalFirmwareRev, entPhysicalSoftwareRev, and the entPhysicalSerialNum objects, are only meaningful amongst entPhysicalEntries with the same value of entPhysicalMfgName.
If the manufacturer name string associated with the physical component is unknown to the agent, then this object will contain a zero-length string." ::= { entPhysicalEntry 12 }
entPhysicalModelName OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current 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 agent, then this object will contain a zero-length string." ::= { entPhysicalEntry 13 }
entPhysicalAlias OBJECT-TYPE SYNTAX SnmpAdminString (SIZE (0..32)) MAX-ACCESS read-write STATUS current DESCRIPTION "This object is an 'alias' name for the physical entity, as specified by a network manager, and provides a non-volatile 'handle' for the physical entity.
On the first instantiation of a physical entity, the value of entPhysicalAlias associated with that entity is set to the zero-length string. However, the agent may set the value to a locally unique default value, instead of a zero-length string.
If write access is implemented for an instance of entPhysicalAlias, and a value is written into the instance, the agent must retain the supplied value in the entPhysicalAlias instance (associated with the same physical entity) for as long as that entity remains instantiated. This includes instantiations across all re-initializations/reboots of the network management system, including those resulting in a change of the physical entity's entPhysicalIndex value." ::= { entPhysicalEntry 14 }
Okay bestie, let's get into the asset tracking stuff and the logical entity table 🎀✨
entPhysicalAssetID OBJECT-TYPE
SYNTAX SnmpAdminString (SIZE (0..32))
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object is a user-assigned asset tracking identifier
(as specified by a network manager) for the physical entity,
and provides non-volatile storage of this information.
On the first instantiation of a physical entity, the value
of entPhysicalAssetID associated with that entity is set to
the zero-length string.
Not every physical component will have an asset tracking
identifier, or even need one. Physical entities for which
the associated value of the entPhysicalIsFRU object is equal
to 'false(2)' (e.g., the repeater ports within a repeater
module), do not need their own unique asset tracking
identifier. An agent does not have to provide write access
for such entities, and may instead return a zero-length
string.
If write access is implemented for an instance of
entPhysicalAssetID, and a value is written into the
instance, the agent must retain the supplied value in the
entPhysicalAssetID instance (associated with the same
physical entity) for as long as that entity remains
instantiated. This includes instantiations across all
re-initializations/reboots of the network management system,
including those resulting in a change of the physical
entity's entPhysicalIndex value.
If no asset tracking information is associated with the
physical component, then this object will contain a
zero-length string."
::= { entPhysicalEntry 15 }This one is basically the "remember my sticker label" object 🏷️💖 Writes need to stick around even through reboots, and it's totally fine for the little router ports to just say nothing 🙈
entPhysicalIsFRU OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates whether or not this physical entity
is considered a 'field replaceable unit' by the vendor. If
this object contains the value 'true(1)' then this
entPhysicalEntry identifies a field replaceable unit. For
all entPhysicalEntries that represent components
permanently contained within a field replaceable unit, the
value 'false(2)' should be returned for this object."
::= { entPhysicalEntry 16 }The FRU flag 🔧✨ true means "you can swap this out", and anything permanently living inside that thing gets false 💅
entPhysicalMfgDate OBJECT-TYPE
SYNTAX DateAndTime
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains the date of manufacturing of the
managed entity. If the manufacturing date is unknown or not
supported, the object is not instantiated. The special
value '0000000000000000'H may also be returned in this
case."
::= { entPhysicalEntry 17 }Manufacturing date 📅🌸 If nobody knows it, the object just doesn't show up, or it can return that special all-zeros value. Iconic, honestly.
entPhysicalUris OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object contains additional identification information
about the physical entity. The object contains URIs and,
therefore, the syntax of this object must conform to RFC
3986, section 2.
Multiple URIs may be present and are separated by white
space characters. Leading and trailing white space
characters are ignored.
If no additional identification information is known
about the physical entity or supported, the object is not
instantiated. A zero length octet string may also be
returned in this case."
REFERENCE
"RFC 3986, Uniform Resource Identifiers (URI): Generic
Syntax, section 2, August 1998."
::= { entPhysicalEntry 18 }URIs 🦋🔗 This is where the extra identification links go. Multiple ones are split up by whitespace, and the URI syntax has to follow RFC 3986 section 2, no cap.
-- The Logical Entity Table
entLogicalTable OBJECT-TYPE
SYNTAX SEQUENCE OF EntLogicalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table contains one row per logical entity. For agents
that implement more than one naming scope, at least one
entry must exist. Agents which instantiate all MIB objects
within a single naming scope are not required to implement
this table."
::= { entityLogical 1 }
entLogicalEntry OBJECT-TYPE
SYNTAX EntLogicalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular logical entity. Entities
may be managed by this agent or other SNMP agents (possibly)
in the same chassis."
INDEX { entLogicalIndex }
::= { entLogicalTable 1 }
EntLogicalEntry ::= SEQUENCE {
entLogicalIndex Integer32,
entLogicalDescr SnmpAdminString,
entLogicalType AutonomousType,
entLogicalCommunity OCTET STRING,
entLogicalTAddress TAddress,
entLogicalTDomain TDomain,
entLogicalContextEngineID SnmpEngineIdOrNone,
entLogicalContextName SnmpAdminString
}
entLogicalIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The value of this object uniquely identifies the logical
entity. The value should be a small positive integer; index
values for different logical entities are not necessarily
contiguous."
::= { entLogicalEntry 1 }
entLogicalDescr OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A textual description of the logical entity. This object
should contain a string that identifies the manufacturer's
name for the logical entity, and should be set to a distinct
value for each version of the logical entity."
::= { entLogicalEntry 2 }
entLogicalType OBJECT-TYPE
SYNTAX AutonomousType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An indication of the type of logical entity. This will
typically be the OBJECT IDENTIFIER name of the node in the
SMI's naming hierarchy which represents the major MIB
module, or the majority of the MIB modules, supported by the
logical entity. For example:
a logical entity of a regular host/router -> mib-2
a logical entity of a 802.1d bridge -> dot1dBridge
a logical entity of a 802.3 repeater -> snmpDot3RptrMgmt
If an appropriate node in the SMI's naming hierarchy cannot
be identified, the value 'mib-2' should be used."
::= { entLogicalEntry 3 }
entLogicalCommunity OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..255))
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"An SNMPv1 or SNMPv2C community-string, which can be used to
access detailed management information for this logical
entity. The agent should allow read access with this
community string (to an appropriate subset of all managed
objects) and may also return a community string based on the
privileges of the request used to read this object. Note
that an agent may return a community string with read-only
privileges, even if this object is accessed with a
read-write community string. However, the agent must take
care not to return a community string that allows more
privileges than the community string used to access this
object.
A compliant SNMP agent may wish to conserve naming scopes by
representing multiple logical entities in a single 'default'
naming scope. This is possible when the logical entities,
represented by the same value of entLogicalCommunity, have
no object instances in common. For example, 'bridge1' and
'repeater1' may be part of the main naming scope, but at
least one additional community string is needed to represent
'bridge2' and 'repeater2'.
Logical entities 'bridge1' and 'repeater1' would be
represented by sysOREntries associated with the 'default'
naming scope.
For agents not accessible via SNMPv1 or SNMPv2C, the value
of this object is the empty string. This object may also
contain an empty string if a community string has not yet
been assigned by the agent, or if no community string with
suitable access rights can be returned for a particular SNMP
request.
Note that this object is deprecated. Agents which implement
SNMPv3 access should use the entLogicalContextEngineID and
entLogicalContextName objects to identify the context
associated with each logical entity. SNMPv3 agents may
return a zero-length string for this object, or may continue
to return a community string (e.g., tri-lingual agent
support)."
::= { entLogicalEntry 4 }
entLogicalTAddress OBJECT-TYPE
SYNTAX TAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The transport service address by which the logical entity
receives network management traffic, formatted according to
the corresponding value of entLogicalTDomain.
For snmpUDPDomain, a TAddress is 6 octets long: the initial
4 octets contain the IP-address in network-byte order and
the last 2 contain the UDP port in network-byte order.
Consult 'Transport Mappings for the Simple Network
Management Protocol' (STD 62, RFC 3417 [RFC3417]) for
further information on snmpUDPDomain."
::= { entLogicalEntry 5 }entLogicalTDomain OBJECT-TYPE SYNTAX TDomain MAX-ACCESS read-only STATUS current DESCRIPTION "Indicates the kind of transport service by which the logical entity receives network management traffic. Possible values for this object are presently found in the Transport Mappings for Simple Network Management Protocol' (STD 62, RFC 3417 [RFC3417])." ::= { entLogicalEntry 6 }
entLogicalContextEngineID OBJECT-TYPE SYNTAX SnmpEngineIdOrNone MAX-ACCESS read-only STATUS current DESCRIPTION "The authoritative contextEngineID that can be used to send an SNMP message concerning information held by this logical entity, to the address specified by the associated 'entLogicalTAddress/entLogicalTDomain' pair.
This object, together with the associated entLogicalContextName object, defines the context associated with a particular logical entity, and allows access to SNMP engines identified by a contextEngineId and contextName pair.
If no value has been configured by the agent, a zero-length string is returned, or the agent may choose not to instantiate this object at all." ::= { entLogicalEntry 7 }
entLogicalContextName OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current DESCRIPTION "The contextName that can be used to send an SNMP message concerning information held by this logical entity, to the address specified by the associated 'entLogicalTAddress/entLogicalTDomain' pair.
This object, together with the associated entLogicalContextEngineID object, defines the context associated with a particular logical entity, and allows access to SNMP engines identified by a contextEngineId and contextName pair.
If no value has been configured by the agent, a zero-length string is returned, or the agent may choose not to instantiate this object at all." ::= { entLogicalEntry 8 }
entLPMappingTable OBJECT-TYPE SYNTAX SEQUENCE OF EntLPMappingEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains zero or more rows of logical entity to physical equipment associations. For each logical entity known by this agent, there are zero or more mappings to the physical resources, which are used to realize that logical entity.
An agent should limit the number and nature of entries in this table such that only meaningful and non-redundant information is returned. For example, in a system that contains a single power supply, mappings between logical entities and the power supply are not useful and should not be included.
Also, only the most appropriate physical component, which is closest to the root of a particular containment tree, should be identified in an entLPMapping entry.
For example, suppose a bridge is realized on a particular module, and all ports on that module are ports on this bridge. A mapping between the bridge and the module would be useful, but additional mappings between the bridge and each of the ports on that module would be redundant (because the entPhysicalContainedIn hierarchy can provide the same information). On the other hand, if more than one bridge were utilizing ports on this module, then mappings between each bridge and the ports it used would be appropriate.
Also, in the case of a single backplane repeater, a mapping for the backplane to the single repeater entity is not necessary." ::= { entityMapping 1 }
entLPMappingEntry OBJECT-TYPE SYNTAX EntLPMappingEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Information about a particular logical entity to physical equipment association. Note that the nature of the association is not specifically identified in this entry. It is expected that sufficient information exists in the MIBs used to manage a particular logical entity to infer how physical component information is utilized." INDEX { entLogicalIndex, entLPPhysicalIndex } ::= { entLPMappingTable 1 }
EntLPMappingEntry ::= SEQUENCE { entLPPhysicalIndex PhysicalIndex }
entLPPhysicalIndex OBJECT-TYPE SYNTAX PhysicalIndex MAX-ACCESS read-only STATUS current DESCRIPTION "The value of this object identifies the index value of a particular entPhysicalEntry associated with the indicated entLogicalEntity." ::= { entLPMappingEntry 1 }
-- logical entity/component to alias table entAliasMappingTable OBJECT-TYPE SYNTAX SEQUENCE OF EntAliasMappingEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains zero or more rows, representing mappings of logical entity and physical component to external MIB identifiers. Each physical port in the system may be associated with a mapping to an external identifier, which itself is associated with a particular logical entity's naming scope. A 'wildcard' mechanism is provided to indicate that an identifier is associated with more than one logical entity." ::= { entityMapping 2 }
entAliasMappingEntry OBJECT-TYPE SYNTAX EntAliasMappingEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Information about a particular physical equipment, logical entity to external identifier binding. Each logical entity/physical component pair may be associated with one alias mapping. The logical entity index may also be used as a 'wildcard' (refer to the entAliasLogicalIndexOrZero object DESCRIPTION clause for details.)
Note that only entPhysicalIndex values that represent physical ports (i.e., associated entPhysicalClass value is 'port(10)') are permitted to exist in this table." INDEX { entPhysicalIndex, entAliasLogicalIndexOrZero } ::= { entAliasMappingTable 1 }
EntAliasMappingEntry ::= SEQUENCE { entAliasLogicalIndexOrZero Integer32, entAliasMappingIdentifier RowPointer }
entAliasLogicalIndexOrZero OBJECT-TYPE SYNTAX Integer32 (0..2147483647) MAX-ACCESS not-accessible STATUS current DESCRIPTION "The value of this object identifies the logical entity that defines the naming scope for the associated instance of the 'entAliasMappingIdentifier' object.
If this object has a non-zero value, then it identifies the logical entity named by the same value of entLogicalIndex.
If this object has a value of zero, then the mapping between the physical component and the alias identifier for this entAliasMapping entry is associated with all unspecified logical entities. That is, a value of zero (the default mapping) identifies any logical entity that does not have an explicit entry in this table for a particular entPhysicalIndex/entAliasMappingIdentifier pair.
For example, to indicate that a particular interface (e.g., physical component 33) is identified by the same value of ifIndex for all logical entities, the following instance might exist:
entAliasMappingIdentifier.33.0 = ifIndex.5
In the event an entPhysicalEntry is associated differently for some logical entities, additional entAliasMapping entries may exist, e.g.:
entAliasMappingIdentifier.33.0 = ifIndex.6 entAliasMappingIdentifier.33.4 = ifIndex.1 entAliasMappingIdentifier.33.5 = ifIndex.1 entAliasMappingIdentifier.33.10 = ifIndex.12
Note that entries with non-zero entAliasLogicalIndexOrZero index values have precedence over zero-indexed entries. In this example, all logical entities except 4, 5, and 10, associate physical entity 33 with ifIndex.6." ::= { entAliasMappingEntry 1 }
entAliasMappingIdentifier OBJECT-TYPE SYNTAX RowPointer MAX-ACCESS read-only STATUS current DESCRIPTION "The value of this object identifies a particular conceptual row associated with the indicated entPhysicalIndex and entLogicalIndex pair.
Because only physical ports are modeled in this table, only entries that represent interfaces or ports are allowed. If an ifEntry exists on behalf of a particular physical port, then this object should identify the associated 'ifEntry'. For repeater ports, the appropriate row in the 'rptrPortGroupTable' should be identified instead.
For example, suppose a physical port was represented by entPhysicalEntry.3, entLogicalEntry.15 existed for a repeater, and entLogicalEntry.22 existed for a bridge. Then there might be two related instances of entAliasMappingIdentifier: entAliasMappingIdentifier.3.15 == rptrPortGroupIndex.5.2 entAliasMappingIdentifier.3.22 == ifIndex.17 It is possible that other mappings (besides interfaces and repeater ports) may be defined in the future, as required.
Bridge ports are identified by examining the Bridge MIB and appropriate ifEntries associated with each 'dot1dBasePort', and are thus not represented in this table." ::= { entAliasMappingEntry 2 }
-- physical mapping table entPhysicalContainsTable OBJECT-TYPE SYNTAX SEQUENCE OF EntPhysicalContainsEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A table that exposes the container/'containee' relationships between physical entities. This table provides all the information found by constructing the virtual containment tree for a given entPhysicalTable, but in a more direct format.
In the event a physical entity is contained by more than one other physical entity (e.g., double-wide modules), this table should include these additional mappings, which cannot be represented in the entPhysicalTable virtual containment tree." ::= { entityMapping 3 }
entPhysicalContainsEntry OBJECT-TYPE SYNTAX EntPhysicalContainsEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A single container/'containee' relationship." INDEX { entPhysicalIndex, entPhysicalChildIndex } ::= { entPhysicalContainsTable 1 }
EntPhysicalContainsEntry ::= SEQUENCE { entPhysicalChildIndex PhysicalIndex }
entPhysicalChildIndex OBJECT-TYPE SYNTAX PhysicalIndex MAX-ACCESS read-only STATUS current DESCRIPTION "The value of entPhysicalIndex for the contained physical entity." ::= { entPhysicalContainsEntry 1 }
-- last change time stamp for the whole MIB
okay so this next bit is where the MIB gets its general "something changed" stamp 💖 entLastChangeTime is the sysUpTime value from whenever a row gets created, modified, or deleted in any of those five tables ✨
entLastChangeTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime at the time a conceptual row is
created, modified, or deleted in any of these tables:
- entPhysicalTable
- entLogicalTable
- entLPMappingTable
- entAliasMappingTable
- entPhysicalContainsTable
"
::= { entityGeneral 1 }now the traps 🔔 entConfigChange is the notification that fires when entLastChangeTime changes, and NMSes can use it to kick off table polls 🫶 the throttling rules are wild, so read them closely 👀
-- Entity MIB Trap Definitions
entityMIBTraps OBJECT IDENTIFIER ::= { entityMIB 2 }
entityMIBTrapPrefix OBJECT IDENTIFIER ::= { entityMIBTraps 0 }
entConfigChange NOTIFICATION-TYPE
STATUS current
DESCRIPTION
"An entConfigChange notification is generated when the value
of entLastChangeTime changes. It can be utilized by an NMS
to trigger logical/physical entity table maintenance polls.
An agent should not generate more than one entConfigChange
'notification-event' in a given time interval (five seconds
is the suggested default). A 'notification-event' is the
transmission of a single trap or inform PDU to a list of
notification destinations.
If additional configuration changes occur within the
throttling period, then notification-events for these
changes should be suppressed by the agent until the current
throttling period expires. At the end of a throttling
period, one notification-event should be generated if any
configuration changes occurred since the start of the
throttling period. In such a case, another throttling
period is started right away.
An NMS should periodically check the value of
entLastChangeTime to detect any missed entConfigChange
notification-events, e.g., due to throttling or transmission
loss."
::= { entityMIBTrapPrefix 1 }next up is conformance 🎀 the compliance statements tell you which groups a device has to implement depending on which version of the Entity MIB it's doing 💅
-- conformance information
entityConformance OBJECT IDENTIFIER ::= { entityMIB 3 }
entityCompliances OBJECT IDENTIFIER ::= { entityConformance 1 }
entityGroups OBJECT IDENTIFIER ::= { entityConformance 2 }
-- compliance statements
entityCompliance MODULE-COMPLIANCE
STATUS deprecated
DESCRIPTION
"The compliance statement for SNMP entities that implement
version 1 of the Entity MIB."
MODULE -- this module
MANDATORY-GROUPS {
entityPhysicalGroup,
entityLogicalGroup,
entityMappingGroup,
entityGeneralGroup,
entityNotificationsGroup
}
::= { entityCompliances 1 }
entity2Compliance MODULE-COMPLIANCE
STATUS deprecated
DESCRIPTION
"The compliance statement for SNMP entities that implement
version 2 of the Entity MIB."
MODULE -- this module
MANDATORY-GROUPS {
entityPhysicalGroup,
entityPhysical2Group,
entityGeneralGroup,
entityNotificationsGroup
}
GROUP entityLogical2Group
DESCRIPTION
"Implementation of this group is not mandatory for agents
that model all MIB object instances within a single naming
scope."
GROUP entityMappingGroup
DESCRIPTION
"Implementation of the entPhysicalContainsTable is mandatory
for all agents. Implementation of the entLPMappingTable and
entAliasMappingTables are not mandatory for agents that
model all MIB object instances within a single naming scope.
Note that the entAliasMappingTable may be useful for all
agents; however, implementation of the entityLogicalGroup or
entityLogical2Group is required to support this table."
OBJECT entPhysicalSerialNum
MIN-ACCESS not-accessible
DESCRIPTION
"Read and write access is not required for agents that
cannot identify serial number information for physical
entities, and/or cannot provide non-volatile storage for
NMS-assigned serial numbers.
Write access is not required for agents that can identify
serial number information for physical entities, but cannot
provide non-volatile storage for NMS-assigned serial
numbers.
Write access is not required for physical entities for which
the associated value of the entPhysicalIsFRU object is equal
to 'false(2)'."
OBJECT entPhysicalAlias
MIN-ACCESS read-only
DESCRIPTION
"Write access is required only if the associated
entPhysicalClass value is equal to 'chassis(3)'."
OBJECT entPhysicalAssetID
MIN-ACCESS not-accessible
DESCRIPTION
"Read and write access is not required for agents that
cannot provide non-volatile storage for NMS-assigned asset
identifiers.
Write access is not required for physical entities for which
the associated value of the entPhysicalIsFRU object is equal
to 'false(2)'."
OBJECT entPhysicalClass
SYNTAX INTEGER {
other(1),
unknown(2),
chassis(3),
backplane(4),
container(5),
powerSupply(6),
fan(7),
sensor(8),
module(9),
port(10),
stack(11)
}
DESCRIPTION
"Implementation of the 'cpu(12)' enumeration is not
required."
::= { entityCompliances 2 }
entity3Compliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for SNMP entities that implement
version 3 of the Entity MIB."
MODULE -- this module
MANDATORY-GROUPS {
entityPhysicalGroup,
entityPhysical2Group,
entityPhysical3Group,
entityGeneralGroup,
entityNotificationsGroup
}
GROUP entityLogical2Group
DESCRIPTION
"Implementation of this group is not mandatory for agents
that model all MIB object instances within a single naming
scope."
GROUP entityMappingGroup
DESCRIPTION
"Implementation of the entPhysicalContainsTable is mandatory
for all agents. Implementation of the entLPMappingTable and
entAliasMappingTables are not mandatory for agents that
model all MIB object instances within a single naming scope.
Note that the entAliasMappingTable may be useful for all
agents; however, implementation of the entityLogicalGroup or
entityLogical2Group is required to support this table."
OBJECT entPhysicalSerialNum
MIN-ACCESS not-accessible
DESCRIPTION
"Read and write access is not required for agents that
cannot identify serial number information for physical
entities, and/or cannot provide non-volatile storage for
NMS-assigned serial numbers.
Write access is not required for agents that can identify
serial number information for physical entities, but cannot
provide non-volatile storage for NMS-assigned serial
numbers.
Write access is not required for physical entities for
which the associated value of the entPhysicalIsFRU object
is equal to 'false(2)'."
OBJECT entPhysicalAlias
MIN-ACCESS read-only
DESCRIPTION
"Write access is required only if the associated
entPhysicalClass value is equal to 'chassis(3)'."
OBJECT entPhysicalAssetID
MIN-ACCESS not-accessible
DESCRIPTION
"Read and write access is not required for agents that
cannot provide non-volatile storage for NMS-assigned asset
identifiers.
Write access is not required for physical entities for which
the associated value of entPhysicalIsFRU is equal to
'false(2)'."
::= { entityCompliances 3 }last bit for this stretch 🧚 these are the MIB groupings, which just bundle related objects together so compliance can point at them 🍓
-- MIB groupings
entityPhysicalGroup OBJECT-GROUP
OBJECTS {
entPhysicalDescr,
entPhysicalVendorType,
entPhysicalContainedIn,
entPhysicalClass,
entPhysicalParentRelPos,
entPhysicalName
}
STATUS current
DESCRIPTION
"The collection of objects used to represent physical
system components, for which a single agent provides
management information."
::= { entityGroups 1 }
entityLogicalGroup OBJECT-GROUP
OBJECTS {
entLogicalDescr,
entLogicalType,
entLogicalCommunity,
entLogicalTAddress,
entLogicalTDomain
}
STATUS deprecated
DESCRIPTION
"The collection of objects used to represent the list of
logical entities, for which a single agent provides
management information."
::= { entityGroups 2 }
entityMappingGroup OBJECT-GROUP
OBJECTS {
entLPPhysicalIndex,
entAliasMappingIdentifier,
entPhysicalChildIndex
}
STATUS current
DESCRIPTION
"The collection of objects used to represent the
associations between multiple logical entities, physical
components, interfaces, and port identifiers, for which a
single agent provides management information."
::= { entityGroups 3 }
entityGeneralGroup OBJECT-GROUP
OBJECTS {
entLastChangeTime
}
STATUS current
DESCRIPTION
"The collection of objects used to represent general entity
information, for which a single agent provides management
information."
::= { entityGroups 4 }entityNotificationsGroup NOTIFICATION-GROUP
NOTIFICATIONS { entConfigChange }
STATUS current
DESCRIPTION
"The collection of notifications used to indicate Entity MIB
data consistency and general status information."
::= { entityGroups 5 }
entityPhysical2Group OBJECT-GROUP
OBJECTS {
entPhysicalHardwareRev,
entPhysicalFirmwareRev,
entPhysicalSoftwareRev,
entPhysicalSerialNum,
entPhysicalMfgName,
entPhysicalModelName,
entPhysicalAlias,
entPhysicalAssetID,
entPhysicalIsFRU
}
STATUS current
DESCRIPTION
"The collection of objects used to represent physical
system components, for which a single agent provides
management information. This group augments the objects
contained in the entityPhysicalGroup."
::= { entityGroups 6 }
entityLogical2Group OBJECT-GROUP
OBJECTS {
entLogicalDescr,
entLogicalType,
entLogicalTAddress,
entLogicalTDomain,
entLogicalContextEngineID,
entLogicalContextName
}
STATUS current
DESCRIPTION
"The collection of objects used to represent the
list of logical entities, for which a single SNMP entity
provides management information."
::= { entityGroups 7 }
entityPhysical3Group OBJECT-GROUP
OBJECTS {
entPhysicalMfgDate,
entPhysicalUris
}
STATUS current
DESCRIPTION
"The collection of objects used to represent physical
system components, for which a single agent provides
management information. This group augments the objects
contained in the entityPhysicalGroup."
::= { entityGroups 8 }
END4. Usage Examples ✨
Okay, time for the fun part 🎀 These sections walk through the instance values for two example networking devices. I kept them simple on purpose so they're easier to vibe with 💖 Auxiliary components like fans, sensors, empty slots, and sub-modules aren't shown here, but real implementations might model them 🫶
4.1. Router/Bridge
Our first example is a router with two slots 🦋 Each slot holds a 3 port router/bridge module, and every port shows up in the ifTable 🌸 The device also runs two logical instances of OSPF and has two logical bridges, so it's a whole main character situation 👑
Physical entities -- entPhysicalTable:
1 Field-replaceable physical chassis:
entPhysicalDescr.1 == 'Acme Chassis Model 100'
entPhysicalVendorType.1 == acmeProducts.chassisTypes.1
entPhysicalContainedIn.1 == 0
entPhysicalClass.1 == chassis(3)
entPhysicalParentRelPos.1 == 0
entPhysicalName.1 == '100-A'
entPhysicalHardwareRev.1 == 'A(1.00.02)'
entPhysicalSoftwareRev.1 == ''
entPhysicalFirmwareRev.1 == ''
entPhysicalSerialNum.1 == 'C100076544'
entPhysicalMfgName.1 == 'Acme'
entPhysicalModelName.1 == '100'
entPhysicalAlias.1 == 'cl-SJ17-3-006:rack1:rtr-U3'
entPhysicalAssetID.1 == '0007372293'
entPhysicalIsFRU.1 == true(1)
entPhysicalMfgDate.1 == '2002-5-26,13:30:30.0,-4:0'
entPhysicalUris.1 == 'URN:CLEI:CNME120ARA'
2 slots within the chassis:
entPhysicalDescr.2 == 'Acme Chassis Slot Type AA'
entPhysicalVendorType.2 == acmeProducts.slotTypes.1
entPhysicalContainedIn.2 == 1
entPhysicalClass.2 == container(5)
entPhysicalParentRelPos.2 == 1
entPhysicalName.2 == 'S1'
entPhysicalHardwareRev.2 == 'B(1.00.01)'
entPhysicalSoftwareRev.2 == ''
entPhysicalFirmwareRev.2 == ''
entPhysicalSerialNum.2 == ''
entPhysicalMfgName.2 == 'Acme'
entPhysicalModelName.2 == 'AA'
entPhysicalAlias.2 == ''
entPhysicalAssetID.2 == ''
entPhysicalIsFRU.2 == false(2)
entPhysicalMfgDate.2 == '2002-7-26,12:22:12.0,-4:0'
entPhysicalUris.2 == 'URN:CLEI:CNME123ARA'
entPhysicalDescr.3 == 'Acme Chassis Slot Type AA'
entPhysicalVendorType.3 = acmeProducts.slotTypes.1
entPhysicalContainedIn.3 == 1
entPhysicalClass.3 == container(5)
entPhysicalParentRelPos.3 == 2
entPhysicalName.3 == 'S2'
entPhysicalHardwareRev.3 == '1.00.07'
entPhysicalSoftwareRev.3 == ''
entPhysicalFirmwareRev.3 == ''
entPhysicalSerialNum.3 == ''
entPhysicalMfgName.3 == 'Acme'
entPhysicalModelName.3 == 'AA'
entPhysicalAlias.3 == ''
entPhysicalAssetID.3 == ''
entPhysicalIsFRU.3 == false(2)
entPhysicalMfgDate.3 == '2002-7-26,12:12:12.0,-4:0'
entPhysicalUris.3 == 'URN:CLEI:CNME123ARA'
2 Field-replaceable modules:
Slot 1 contains a module with 3 ports:
entPhysicalDescr.4 == 'Acme Router-100'
entPhysicalVendorType.4 == acmeProducts.moduleTypes.14
entPhysicalContainedIn.4 == 2
entPhysicalClass.4 == module(9)
entPhysicalParentRelPos.4 == 1
entPhysicalName.4 == 'M1'
entPhysicalHardwareRev.4 == '1.00.07'
entPhysicalSoftwareRev.4 == '1.4.1'
entPhysicalFirmwareRev.4 == 'A(1.1)'
entPhysicalSerialNum.4 == 'C100087363'
entPhysicalMfgName.4 == 'Acme'
entPhysicalModelName.4 == 'R100-FE'
entPhysicalAlias.4 == 'rtr-U3:m1:SJ17-3-eng'
entPhysicalAssetID.4 == '0007372462'
entPhysicalIsFRU.4 == true(1)
entPhysicalMfgDate.4 == '2003-7-18,13:30:30.0,-4:0'
entPhysicalUris.4 == 'URN:CLEI:CNRU123CAA'
entPhysicalDescr.5 == 'Acme Ethernet-100 Port'
entPhysicalVendorType.5 == acmeProducts.portTypes.2
entPhysicalContainedIn.5 == 4
entPhysicalClass.5 == port(10)
entPhysicalParentRelPos.5 == 1
entPhysicalName.5 == 'P1'
entPhysicalHardwareRev.5 == 'G(1.02)'
entPhysicalSoftwareRev.5 == ''
entPhysicalFirmwareRev.5 == '1.1'
entPhysicalSerialNum.5 == ''
entPhysicalMfgName.5 == 'Acme'
entPhysicalModelName.5 == 'FE-100'
entPhysicalAlias.5 == ''
entPhysicalAssetID.5 == ''
entPhysicalIsFRU.5 == false(2)
entPhysicalMfgDate.5 == '2003-7-18,14:20:22.0,-4:0'
entPhysicalUris.5 == 'URN:CLEI:CNMES23ARA'
entPhysicalDescr.6 == 'Acme Ethernet-100 Port'
entPhysicalVendorType.6 == acmeProducts.portTypes.2
entPhysicalContainedIn.6 == 4
entPhysicalClass.6 == port(10)
entPhysicalParentRelPos.6 == 2
entPhysicalName.6 == 'P2'
entPhysicalHardwareRev.6 == 'G(1.02)'
entPhysicalSoftwareRev.6 == ''
entPhysicalFirmwareRev.6 == '1.1'
entPhysicalSerialNum.6 == ''
entPhysicalMfgName.6 == 'Acme'
entPhysicalModelName.6 == 'FE-100'
entPhysicalAlias.6 == ''
entPhysicalAssetID.6 == ''
entPhysicalIsFRU.6 == false(2)
entPhysicalMfgDate.6 == '2003-7-19,10:15:15.0,-4:0'
entPhysicalUris.6 == 'URN:CLEI:CNMES23ARA'
entPhysicalDescr.7 == 'Acme Router-100 FDDI-Port'
entPhysicalVendorType.7 == acmeProducts.portTypes.3
entPhysicalContainedIn.7 == 4
entPhysicalClass.7 == port(10)
entPhysicalParentRelPos.7 == 3
entPhysicalName.7 == 'P3'
entPhysicalHardwareRev.7 == 'B(1.03)'
entPhysicalSoftwareRev.7 == '2.5.1'
entPhysicalFirmwareRev.7 == '2.5F'
entPhysicalSerialNum.7 == ''
entPhysicalMfgName.7 == 'Acme'
entPhysicalModelName.7 == 'FDDI-100'
entPhysicalAlias.7 == ''
entPhysicalAssetID.7 == ''
entPhysicalIsFRU.7 == false(2)
Slot 2 contains another 3-port module:
entPhysicalDescr.8 == 'Acme Router-100 Comm Module'
entPhysicalVendorType.8 == acmeProducts.moduleTypes.15
entPhysicalContainedIn.8 == 3
entPhysicalClass.8 == module(9)
entPhysicalParentRelPos.8 == 1
entPhysicalName.8 == 'M2'
entPhysicalHardwareRev.8 == '2.01.00'
entPhysicalSoftwareRev.8 == '3.0.7'
entPhysicalFirmwareRev.8 == 'A(1.2)'
entPhysicalSerialNum.8 == 'C100098732'
entPhysicalMfgName.8 == 'Acme'
entPhysicalModelName.8 == 'C100'
entPhysicalAlias.8 == 'rtr-U3:m2:SJ17-2-eng'
entPhysicalAssetID.8 == '0007373982'
entPhysicalIsFRU.8 == true(1)
entPhysicalMfgDate.8 == '2002-5-26,13:30:15.0,-4:0'
entPhysicalUris.8 == 'URN:CLEI:CNRT321MAA'
entPhysicalDescr.9 == 'Acme Fddi-100 Port'
entPhysicalVendorType.9 == acmeProducts.portTypes.5
entPhysicalContainedIn.9 == 8
entPhysicalClass.9 == port(10)
entPhysicalParentRelPos.9 == 1
entPhysicalName.9 == 'FDDI Primary'
entPhysicalHardwareRev.9 == 'CC(1.07)'
entPhysicalSoftwareRev.9 == '2.0.34'
entPhysicalFirmwareRev.9 == '1.1'
entPhysicalSerialNum.9 == ''
entPhysicalMfgName.9 == 'Acme'
entPhysicalModelName.9 == 'FDDI-100'
entPhysicalAlias.9 == ''
entPhysicalAssetID.9 == ''
entPhysicalIsFRU.9 == false(2)
entPhysicalDescr.10 == 'Acme Ethernet-100 Port'
entPhysicalVendorType.10 == acmeProducts.portTypes.2
entPhysicalContainedIn.10 == 8
entPhysicalClass.10 == port(10)
entPhysicalParentRelPos.10 == 2
entPhysicalName.10 == 'Ethernet A'
entPhysicalHardwareRev.10 == 'G(1.04)'
entPhysicalSoftwareRev.10 == ''
entPhysicalFirmwareRev.10 == '1.3'
entPhysicalSerialNum.10 == ''
entPhysicalMfgName.10 == 'Acme'
entPhysicalModelName.10 == 'FE-100'
entPhysicalAlias.10 == ''
entPhysicalAssetID.10 == ''
entPhysicalIsFRU.10 == false(2)
entPhysicalMfgDate.10 == '2002-7-26,13:30:15.0,-4:0'
entPhysicalUris.10 == 'URN:CLEI:CNMES23ARA' entPhysicalDescr.11 == 'Acme Ethernet-100 Port'
entPhysicalVendorType.11 == acmeProducts.portTypes.2
entPhysicalContainedIn.11 == 8
entPhysicalClass.11 == port(10)
entPhysicalParentRelPos.11 == 3
entPhysicalName.11 == 'Ethernet B'
entPhysicalHardwareRev.11 == 'G(1.04)'
entPhysicalSoftwareRev.11 == ''
entPhysicalFirmwareRev.11 == '1.3'
entPhysicalSerialNum.11 == ''
entPhysicalMfgName.11 == 'Acme'
entPhysicalModelName.11 == 'FE-100'
entPhysicalAlias.11 == ''
entPhysicalAssetID.11 == ''
entPhysicalIsFRU.11 == false(2)
entPhysicalMfgDate.11 == '2002-8-16,15:35:15.0,-4:0'
entPhysicalUris.11 == 'URN:CLEI:CNMES23ARA'
Logical entities -- entLogicalTable; no SNMPv3 support
2 OSPF instances:
entLogicalDescr.1 == 'Acme OSPF v1.1'
entLogicalType.1 == ospf
entLogicalCommunity.1 == 'public-ospf1'
entLogicalTAddress.1 == 192.0.2.1:161
entLogicalTDomain.1 == snmpUDPDomain
entLogicalContextEngineID.1 == ''
entLogicalContextName.1 == ''
entLogicalDescr.2 == 'Acme OSPF v1.1'
entLogicalType.2 == ospf
entLogicalCommunity.2 == 'public-ospf2'
entLogicalTAddress.2 == 192.0.2.1:161
entLogicalTDomain.2 == snmpUDPDomain
entLogicalContextEngineID.2 == ''
entLogicalContextName.2 == ''
2 logical bridges:
entLogicalDescr.3 == 'Acme Bridge v2.1.1'
entLogicalType.3 == dot1dBridge
entLogicalCommunity.3 == 'public-bridge1'
entLogicalTAddress.3 == 192.0.2.1:161
entLogicalTDomain.3 == snmpUDPDomain
entLogicalContextEngineID.3 == ''
entLogicalContextName.3 == ''
entLogicalDescr.4 == 'Acme Bridge v2.1.1'
entLogicalType.4 == dot1dBridge
entLogicalCommunity.4 == 'public-bridge2'
entLogicalTAddress.4 == 192.0.2.1:161
entLogicalTDomain.4 == snmpUDPDomain
entLogicalContextEngineID.4 == ''
entLogicalContextName.4 == ''
Logical to Physical Mappings:
1st OSPF instance: uses module 1-port 1
entLPPhysicalIndex.1.5 == 5
2nd OSPF instance: uses module 2-port 1
entLPPhysicalIndex.2.9 == 9
1st bridge group: uses module 1, all ports
[ed. -- Note that these mappings are included in the table because
another logical entity (1st OSPF) utilizes one of the
ports. If this were not the case, then a single mapping
to the module (e.g., entLPPhysicalIndex.3.4) would be
present instead.]
entLPPhysicalIndex.3.5 == 5
entLPPhysicalIndex.3.6 == 6
entLPPhysicalIndex.3.7 == 7
2nd bridge group: uses module 2, all ports
entLPPhysicalIndex.4.9 == 9
entLPPhysicalIndex.4.10 == 10
entLPPhysicalIndex.4.11 == 11
Physical to Logical to MIB Alias Mappings -- entAliasMappingTable:
Example 1: ifIndex values are global to all logical entities
entAliasMappingIdentifier.5.0 == ifIndex.1
entAliasMappingIdentifier.6.0 == ifIndex.2
entAliasMappingIdentifier.7.0 == ifIndex.3
entAliasMappingIdentifier.9.0 == ifIndex.4
entAliasMappingIdentifier.10.0 == ifIndex.5
entAliasMappingIdentifier.11.0 == ifIndex.6
Example 2: ifIndex values are not shared by all logical entities;
(Bridge-1 uses ifIndex values 101 - 103 and Bridge-2 uses
ifIndex values 204-206.)
entAliasMappingIdentifier.5.0 == ifIndex.1
entAliasMappingIdentifier.5.3 == ifIndex.101
entAliasMappingIdentifier.6.0 == ifIndex.2
entAliasMappingIdentifier.6.3 == ifIndex.102
entAliasMappingIdentifier.7.0 == ifIndex.3
entAliasMappingIdentifier.7.3 == ifIndex.103
entAliasMappingIdentifier.9.0 == ifIndex.4
entAliasMappingIdentifier.9.4 == ifIndex.204
entAliasMappingIdentifier.10.0 == ifIndex.5
entAliasMappingIdentifier.10.4 == ifIndex.205
entAliasMappingIdentifier.11.0 == ifIndex.6
entAliasMappingIdentifier.11.4 == ifIndex.206
Physical Containment Tree -- entPhysicalContainsTable
chassis has two containers:
entPhysicalChildIndex.1.2 == 2
entPhysicalChildIndex.1.3 == 3
container 1 has a module:
entPhysicalChildIndex.2.4 == 4
container 2 has a module:
entPhysicalChildIndex.3.8 == 8
module 1 has 3 ports:
entPhysicalChildIndex.4.5 == 5
entPhysicalChildIndex.4.6 == 6
entPhysicalChildIndex.4.7 == 7
module 2 has 3 ports:
entPhysicalChildIndex.8.9 == 9
entPhysicalChildIndex.8.10 == 10
entPhysicalChildIndex.8.11 == 114.2. Repeaters ✨
okay bestie, this one is a 3-slot Hub with 2 backplane ethernet segments 🍓 Slot three is empty rn, and the remaining slots hold ethernet repeater modules 🔥
ngl this example assumes an older Repeater MIB implementation (RFC 1516 [RFC1516]) instead of the new Repeater MIB (RFC 2108 [RFC2108]) 💀 The new version has an object called rptrPortRptrId, which should be used to identify repeater port groupings, rather than using community strings or contexts 🦋
Physical entities -- entPhysicalTable:
1 Field-replaceable physical chassis:
entPhysicalDescr.1 == 'Acme Chassis Model 110'
entPhysicalVendorType.1 == acmeProducts.chassisTypes.2
entPhysicalContainedIn.1 == 0
entPhysicalClass.1 == chassis(3)
entPhysicalParentRelPos.1 ==0
entPhysicalName.1 == '110-B'
entPhysicalHardwareRev.1 == 'A(1.02.00)'
entPhysicalSoftwareRev.1 == ''
entPhysicalFirmwareRev.1 == ''
entPhysicalSerialNum.1 == 'C100079294'
entPhysicalMfgName.1 == 'Acme'
entPhysicalModelName.1 == '110'
entPhysicalAlias.1 == 'bldg09:floor1:rptr18:0067eea0229f'
entPhysicalAssetID.1 == '0007386327'
entPhysicalIsFRU.1 == true(1)
2 Chassis Ethernet Backplanes:
entPhysicalDescr.2 == 'Acme Ethernet Backplane Type A'
entPhysicalVendorType.2 == acmeProducts.backplaneTypes.1
entPhysicalContainedIn.2 == 1
entPhysicalClass.2 == backplane(4)
entPhysicalParentRelPos.2 == 1
entPhysicalName.2 == 'B1'
entPhysicalHardwareRev.2 == 'A(2.04.01)'
entPhysicalSoftwareRev.2 == ''
entPhysicalFirmwareRev.2 == ''
entPhysicalSerialNum.2 == ''
entPhysicalMfgName.2 == 'Acme'
entPhysicalModelName.2 == 'BK-A'
entPhysicalAlias.2 == ''
entPhysicalAssetID.2 == ''
entPhysicalIsFRU.2 == false(2)
entPhysicalDescr.3 == 'Acme Ethernet Backplane Type A'
entPhysicalVendorType.3 == acmeProducts.backplaneTypes.1
entPhysicalContainedIn.3 == 1
entPhysicalClass.3 == backplane(4)
entPhysicalParentRelPos.3 == 2
entPhysicalName.3 == 'B2'
entPhysicalHardwareRev.3 == 'A(2.04.01)'
entPhysicalSoftwareRev.3 == ''
entPhysicalFirmwareRev.3 == ''
entPhysicalSerialNum.3 == ''
entPhysicalMfgName.3 == 'Acme'
entPhysicalModelName.3 == 'BK-A'
entPhysicalAlias.3 == ''
entPhysicalAssetID.3 == ''
entPhysicalIsFRU.3 == false(2)
3 slots within the chassis:
entPhysicalDescr.4 == 'Acme Hub Slot Type RB'
entPhysicalVendorType.4 == acmeProducts.slotTypes.5
entPhysicalContainedIn.4 == 1
entPhysicalClass.4 == container(5)
entPhysicalParentRelPos.4 == 1
entPhysicalName.4 == 'Slot 1'
entPhysicalHardwareRev.4 == 'B(1.00.03)'
entPhysicalSoftwareRev.4 == ''
entPhysicalFirmwareRev.4 == ''
entPhysicalSerialNum.4 == ''
entPhysicalMfgName.4 == 'Acme'
entPhysicalModelName.4 == 'RB'
entPhysicalAlias.4 == ''
entPhysicalAssetID.4 == ''
entPhysicalIsFRU.4 == false(2)
entPhysicalDescr.5 == 'Acme Hub Slot Type RB'
entPhysicalVendorType.5 == acmeProducts.slotTypes.5
entPhysicalContainedIn.5 == 1
entPhysicalClass.5 == container(5)
entPhysicalParentRelPos.5 == 2
entPhysicalName.5 == 'Slot 2'
entPhysicalHardwareRev.5 == 'B(1.00.03)'
entPhysicalSoftwareRev.5 == ''
entPhysicalFirmwareRev.5 == ''
entPhysicalSerialNum.5 == ''
entPhysicalMfgName.5 == 'Acme'
entPhysicalModelName.5 == 'RB'
entPhysicalAlias.5 == ''
entPhysicalAssetID.5 == ''
entPhysicalIsFRU.5 == false(2)
entPhysicalDescr.6 == 'Acme Hub Slot Type RB'
entPhysicalVendorType.6 == acmeProducts.slotTypes.5
entPhysicalContainedIn.6 == 1
entPhysicalClass.6 == container(5)
entPhysicalParentRelPos.6 == 3
entPhysicalName.6 == 'Slot 3'
entPhysicalHardwareRev.6 == 'B(1.00.03)'
entPhysicalSoftwareRev.6 == ''
entPhysicalFirmwareRev.6 == ''
entPhysicalSerialNum.6 == ''
entPhysicalMfgName.6 == 'Acme'
entPhysicalModelName.6 == 'RB'
entPhysicalAlias.6 == ''
entPhysicalAssetID.6 == ''
entPhysicalIsFRU.6 == false(2)
Slot 1 contains a plug-in module with 4 10-BaseT ports:
entPhysicalDescr.7 == 'Acme 10Base-T Module 114'
entPhysicalVendorType.7 == acmeProducts.moduleTypes.32
entPhysicalContainedIn.7 == 4
entPhysicalClass.7 == module(9)
entPhysicalParentRelPos.7 == 1
entPhysicalName.7 == 'M1'
entPhysicalHardwareRev.7 == 'A(1.02.01)'
entPhysicalSoftwareRev.7 == '1.7.2'
entPhysicalFirmwareRev.7 == 'A(1.5)'
entPhysicalSerialNum.7 == 'C100096244'
entPhysicalMfgName.7 == 'Acme'
entPhysicalModelName.7 = '114'
entPhysicalAlias.7 == 'bldg09:floor1:eng'
entPhysicalAssetID.7 == '0007962951'
entPhysicalIsFRU.7 == true(1)
entPhysicalDescr.8 == 'Acme 10Base-T Port RB'
entPhysicalVendorType.8 == acmeProducts.portTypes.10
entPhysicalContainedIn.8 == 7
entPhysicalClass.8 == port(10)
entPhysicalParentRelPos.8 == 1
entPhysicalName.8 == 'Ethernet-A'
entPhysicalHardwareRev.8 == 'A(1.04F)'
entPhysicalSoftwareRev.8 == ''
entPhysicalFirmwareRev.8 == '1.4'
entPhysicalSerialNum.8 == ''
entPhysicalMfgName.8 == 'Acme'
entPhysicalModelName.8 == 'RB'
entPhysicalAlias.8 == ''
entPhysicalAssetID.8 == ''
entPhysicalIsFRU.8 == false(2) entPhysicalDescr.9 == 'Acme 10Base-T Port RB'
entPhysicalVendorType.9 == acmeProducts.portTypes.10
entPhysicalContainedIn.9 == 7
entPhysicalClass.9 == port(10)
entPhysicalParentRelPos.9 == 2
entPhysicalName.9 == 'Ethernet-B'
entPhysicalHardwareRev.9 == 'A(1.04F)'
entPhysicalSoftwareRev.9 == ''
entPhysicalFirmwareRev.9 == '1.4'
entPhysicalSerialNum.9 == ''
entPhysicalMfgName.9 == 'Acme'
entPhysicalModelName.9 = 'RB'
entPhysicalAlias.9 == ''
entPhysicalAssetID.9 == ''
entPhysicalIsFRU.9 == false(2)
entPhysicalDescr.10 == 'Acme 10Base-T Port RB'
entPhysicalVendorType.10 == acmeProducts.portTypes.10
entPhysicalContainedIn.10 == 7
entPhysicalClass.10 == port(10)
entPhysicalParentRelPos.10 == 3
entPhysicalName.10 == 'Ethernet-C'
entPhysicalHardwareRev.10 == 'B(1.02.07)'
entPhysicalSoftwareRev.10 == ''
entPhysicalFirmwareRev.10 == '1.4'
entPhysicalSerialNum.10 == ''
entPhysicalMfgName.10 == 'Acme'
entPhysicalModelName.10 == 'RB'
entPhysicalAlias.10 == ''
entPhysicalAssetID.10 == ''
entPhysicalIsFRU.10 == false(2)
entPhysicalDescr.11 == 'Acme 10Base-T Port RB'
entPhysicalVendorType.11 == acmeProducts.portTypes.10
entPhysicalContainedIn.11 == 7
entPhysicalClass.11 == port(10)
entPhysicalParentRelPos.11 == 4
entPhysicalName.11 == 'Ethernet-D'
entPhysicalHardwareRev.11 == 'B(1.02.07)'
entPhysicalSoftwareRev.11 == ''
entPhysicalFirmwareRev.11 == '1.4'
entPhysicalSerialNum.11 == ''
entPhysicalMfgName.11 == 'Acme'
entPhysicalModelName.11 == 'RB'
entPhysicalAlias.11 == ''
entPhysicalAssetID.11 == ''
entPhysicalIsFRU.11 == false(2)
Slot 2 contains another ethernet module with 2 ports.
entPhysicalDescr.12 == 'Acme 10Base-T Module Model 4'
entPhysicalVendorType.12 == acmeProducts.moduleTypes.30
entPhysicalContainedIn.12 = 5
entPhysicalClass.12 == module(9)
entPhysicalParentRelPos.12 == 1
entPhysicalName.12 == 'M2'
entPhysicalHardwareRev.12 == 'A(1.01.07)'
entPhysicalSoftwareRev.12 == '1.8.4'
entPhysicalFirmwareRev.12 == 'A(1.8)'
entPhysicalSerialNum.12 == 'C100102384'
entPhysicalMfgName.12 == 'Acme'
entPhysicalModelName.12 == '4'
entPhysicalAlias.12 == 'bldg09:floor1:devtest'
entPhysicalAssetID.12 == '0007968462'
entPhysicalIsFRU.12 == true(1)
entPhysicalDescr.13 == 'Acme 802.3 AUI Port'
entPhysicalVendorType.13 == acmeProducts.portTypes.11
entPhysicalContainedIn.13 == 12
entPhysicalClass.13 == port(10)
entPhysicalParentRelPos.13 == 1
entPhysicalName.13 == 'AUI'
entPhysicalHardwareRev.13 == 'A(1.06F)'
entPhysicalSoftwareRev.13 == ''
entPhysicalFirmwareRev.13 == '1.5'
entPhysicalSerialNum.13 == ''
entPhysicalMfgName.13 == 'Acme'
entPhysicalModelName.13 == ''
entPhysicalAlias.13 == ''
entPhysicalAssetID.13 == ''
entPhysicalIsFRU.13 == false(2)
entPhysicalDescr.14 == 'Acme 10Base-T Port RD'
entPhysicalVendorType.14 == acmeProducts.portTypes.14
entPhysicalContainedIn.14 == 12
entPhysicalClass.14 == port(10)
entPhysicalParentRelPos.14 == 2
entPhysicalName.14 == 'E2'
entPhysicalHardwareRev.14 == 'B(1.01.02)'
entPhysicalSoftwareRev.14 == ''
entPhysicalFirmwareRev.14 == '2.1'
entPhysicalSerialNum.14 == ''
entPhysicalMfgName.14 == 'Acme'
entPhysicalModelName.14 == ''
entPhysicalAlias.14 == ''
entPhysicalAssetID.14 == ''
entPhysicalIsFRU.14 == false(2)
Logical entities -- entLogicalTable; with SNMPv3 support
Repeater 1--comprised of any ports attached to backplane 1
entLogicalDescr.1 == 'Acme repeater v3.1'
entLogicalType.1 == snmpDot3RptrMgt
entLogicalCommunity.1 'public-repeater1'
entLogicalTAddress.1 == 192.0.2.1:161
entLogicalTDomain.1 == snmpUDPDomain
entLogicalContextEngineID.1 == '80000777017c7d7e7f'H
entLogicalContextName.1 == 'repeater1'
Repeater 2--comprised of any ports attached to backplane 2:
entLogicalDescr.2 == 'Acme repeater v3.1'
entLogicalType.2 == snmpDot3RptrMgt
entLogicalCommunity.2 == 'public-repeater2'
entLogicalTAddress.2 == 192.0.2.1:161
entLogicalTDomain.2 == snmpUDPDomain
entLogicalContextEngineID.2 == '80000777017c7d7e7f'H
entLogicalContextName.2 == 'repeater2'
Logical to Physical Mappings -- entLPMappingTable:
repeater1 uses backplane 1, slot 1-ports 1 & 2, slot 2-port 1
[ed. -- Note that a mapping to the module is not included,
because this example represents a port-switchable hub.
Even though all ports on the module could belong to the
same repeater as a matter of configuration, the LP port
mappings should not be replaced dynamically with a single
mapping for the module (e.g., entLPPhysicalIndex.1.7).
If all ports on the module shared a single backplane connection,
then a single mapping for the module would be more appropriate.]
entLPPhysicalIndex.1.2 == 2
entLPPhysicalIndex.1.8 == 8
entLPPhysicalIndex.1.9 == 9
entLPPhysicalIndex.1.13 == 13
repeater2 uses backplane 2, slot 1-ports 3 & 4, slot 2-port 2
entLPPhysicalIndex.2.3 == 3
entLPPhysicalIndex.2.10 == 10
entLPPhysicalIndex.2.11 == 11
entLPPhysicalIndex.2.14 == 14
Physical to Logical to MIB Alias Mappings -- entAliasMappingTable:
Repeater Port Identifier values are shared by both repeaters:
entAliasMappingIdentifier.8.0 == rptrPortGroupIndex.1.1
entAliasMappingIdentifier.9.0 == rptrPortGroupIndex.1.2
entAliasMappingIdentifier.10.0 == rptrPortGroupIndex.1.3
entAliasMappingIdentifier.11.0 == rptrPortGroupIndex.1.4
entAliasMappingIdentifier.13.0 == rptrPortGroupIndex.2.1
entAliasMappingIdentifier.14.0 == rptrPortGroupIndex.2.2
Physical Containment Tree -- entPhysicalContainsTable
chassis has two backplanes and three containers:
entPhysicalChildIndex.1.2 == 2
entPhysicalChildIndex.1.3 == 3
entPhysicalChildIndex.1.4 == 4
entPhysicalChildIndex.1.5 == 5
entPhysicalChildIndex.1.6 == 6
container 1 has a module:
entPhysicalChildIndex.4.7 == 7
container 2 has a module
entPhysicalChildIndex.5.12 == 12
[ed. -- in this example, container 3 is empty.]
module 1 has 4 ports:
entPhysicalChildIndex.7.8 == 8
entPhysicalChildIndex.7.9 == 9
entPhysicalChildIndex.7.10 == 10
entPhysicalChildIndex.7.11 == 11
module 2 has 2 ports:
entPhysicalChildIndex.12.13 == 13
entPhysicalChildIndex.12.14 == 145. Security Considerations 🔒
okay bestie, this part is serious, so let's be real about it 💀. A bunch of the management objects in this MIB have a MAX-ACCESS clause of read-write and/or read-create. Those objects might be sensitive or vulnerable depending on the network you're in, and SET operations in a non-secure environment, without proper protection, can seriously mess with network operations 😭.
A bunch of objects in this MIB can also hold sensitive info. Here they are:
entPhysicalDescrentPhysicalVendorTypeentPhysicalHardwareReventPhysicalFirmwareReventPhysicalSoftwareReventPhysicalSerialNumentPhysicalMfgNameentPhysicalModelName
These objects spill details about the physical entities inside a managed system, so someone could figure out the vendor, model, and version of each component. Lowkey a lot of info to hand over 👀.
entPhysicalAssetID
This one can expose asset identifiers for different system components, but only if an NMS application actually configures this MIB object 🫣.
entLogicalDescrentLogicalType
These objects show what kinds of logical entities are running on the managed system 🧚.
entLogicalCommunity
This object exposes the community names tied to particular logical entities in the system. Community names are basically a password vibe, so yeah, handle with care 🔑.
entLogicalTAddressentLogicalTDomain
These objects expose network addresses you could use to talk to an SNMP agent on behalf of particular logical entities in the system 🌐.
entLogicalContextEngineIDentLogicalContextName
These objects identify the authoritative SNMP engine holding info on behalf of particular logical entities in the system 🦋.
It is thus important to control even GET access to these objects, and possibly to encrypt their values when sending them over the network via SNMP. Not all versions of SNMP have features for a secure environment, so keep that in mind 🙈.
SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example, by using IPSec), there is still no control over who on that secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB. Not me being like "wait, that's wild" 💀.
It is recommended that implementers consider the security features provided by the SNMPv3 framework. Specifically, the use of the User-based Security Model RFC 3414 [RFC3414] and the View-based Access Control Model RFC 3415 [RFC3415] is recommended. Main character energy means locking this down properly 👑.
It is then a customer or user responsibility to make sure the SNMP entity giving access to an instance of this MIB is configured properly, so that only the principals (users) with legitimate rights can GET or SET (change/create/delete) those objects. Honestly that's the whole vibe 💅.
6. IANA Considerations 📋
The MIB module in this document uses the following IANA-assigned OBJECT IDENTIFIER values, recorded in the SMI Numbers registry:
Descriptor OBJECT IDENTIFIER value
---------- -----------------------
entityMIB { mib-2 47 }7. Acknowledgements 🫶
This memo was produced by the IETF's Entity MIB working group. Shoutout to them, they really did the most 🌸.
8. References ✨
8.1. Normative References ✨
okay so these are the docs this spec literally cannot work without 😭 you NEED to read these first, bestie 💅
[RFC2578]McCloghrie, K., Perkins, D., and J. Schoenwaelder, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.[RFC2579]McCloghrie, K., Perkins, D., and J. Schoenwaelder, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999.[RFC2580]McCloghrie, K., Perkins, D., and J. Schoenwaelder, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999.[RFC3411]Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks", STD 62, RFC 3411, December 2002.[RFC3417]Presuhn, R., "Transport Mappings for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3417, December 2002.[RFC3986]Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005.
8.2. Informative References ✨
these ones are the extra reading 🧚 not strictly required to get the spec, but they give you the backstory and the vibes, so go for it 🌈
[RFC1157]Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol", STD 15, RFC 1157, May 1990.[RFC1493]Decker, E., Langille, P., Rijsinghani, A., and K. McCloghrie, "Definitions of Managed Objects for Bridges", RFC 1493, July 1993.[RFC1516]McMaster, D. and K. McCloghrie, "Definitions of Managed Objects for IEEE 802.3 Repeater Devices", RFC 1516, September 1993.[RFC2037]McCloghrie, K. and A. Bierman, "Entity MIB using SMIv2", RFC 2037, October 1996.[RFC2108]de Graaf, K., Romascanu, D., McMaster, D., and K. McCloghrie, "Definitions of Managed Objects for IEEE 802.3 Repeater Devices using SMIv2", RFC 2108, February 1997.[RFC2737]McCloghrie, K. and A. Bierman, "Entity MIB (Version 2)", RFC 2737, December 1999.[RFC2863]McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000.[RFC3406]Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, "Uniform Resource Names (URN) Namespace Definition Mechanisms", BCP 66, RFC 3406, October 2002.[RFC3410]Case, J., Mundy, R., Partain, D., and B. Stewart, "Introduction and Applicability Statements for Internet-Standard Management Framework", RFC 3410, December 2002.[RFC3414]Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", STD 62, RFC 3414, December 2002.[RFC3415]Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3415, December 2002.[RFC4152]Tesink, K. and R. Fox, "A Uniform Resource Name (URN) Namespace for the CLEI Code", RFC 4152, August 2005.[T1.213]ATIS T1.213-2001, "Coded Identification of Equipment Entities in the North American Telecommunications System for Information Exchange", 2001, www.ansi.org.[T1.213a]ATIS T1.213a, "Supplement to T1.213-2001, Coded Identification of Equipment Entities in the North American Telecommunications System for Information Exchange, to correct the representation of the Basic Code in Figure B.1", 2001, www.ansi.org.
Authors' Addresses 🎀
meet the people who made this happen 🫶
Andy Bierman
EMail: ietf@andybierman.com
Keith McCloghrie Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 USA
Phone: +1 408-526-5260 EMail: kzm@cisco.com
Full Copyright Statement 💜
Copyright (C) The Internet Society (2005).
the legal bit, but make it cute: the authors keep their rights, and this doc is covered by BCP 78. Here's the exact wording so nothing gets lost in translation:
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Intellectual Property 🦋
okay so the IETF is NOT saying whether any patents or rights are out there for this tech, and it doesn't claim it went looking either 🙈 if you want the rules on rights in RFCs, check BCP 78 and BCP 79.
IPR disclosures sent to the IETF Secretariat, plus any licence assurances, or the results of trying to get a general licence or permission for implementers or users, can be found in the IETF online IPR repository at http://www.ietf.org/ipr.
the IETF also invites anyone to flag copyrights, patents, patent applications, or other proprietary rights that might cover technology needed to implement this standard. Send that info to the IETF at ietf-ipr@ietf.org. ✨
Acknowledgement 🌸
Funding for the RFC Editor function is currently provided by the Internet Society. 💖
📦 where this page comes from
- ietf: rfc4133 2005-08
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms