





Network Working Group                                        S. Chisholm
Request for Comments: 4268                               Nortel Networks
Category: Standards Track                                     D. Perkins
                                                                SNMPinfo
                                                           November 2005


                            Entity State MIB

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

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.
   In particular, it describes extensions to the Entity MIB to provide
   information about the state of physical entities.

   In addition, this memo defines a set of Textual Conventions to
   represent various states of an entity.  The intent is that these
   Textual Conventions will be imported and used in MIB modules that
   would otherwise define their own representations.

Table of Contents

   1. The Internet-Standard Management Framework ......................2
   2. Entity State ....................................................2
      2.1. Hierarchical State Management ..............................3
      2.2. Entity Redundancy ..........................................3
      2.3. Physical Entity Users ......................................3
      2.4. Physical Class Behavior ....................................4
   3. Relation to Other MIBs ..........................................4
      3.1. Relation to the Interfaces MIB .............................4
      3.2. Relation to Alarm MIB ......................................5
      3.3. Relation to Bridge MIB .....................................5
      3.4. Relation to the Host Resources MIB .........................5
   4. Textual Conventions .............................................6
   5. Definitions .................................................... 9



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   6. Security Considerations ........................................16
   7. Acknowledgements ...............................................17
   8. References .....................................................17
      8.1. Normative References ......................................17
      8.2. Informative References ....................................18

1.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   Managed objects are accessed via a virtual information store, termed
   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 defined 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.  Entity State

   The goal in adding state objects to the Entity MIB [RFC4133] is to
   define a useful subset of the possible state attributes that could be
   tracked for a given entity and that both fit into the state models
   such as those used in the Interfaces MIB [RFC2863] as well as
   leverage existing well-deployed models.  The entStateTable contains
   state objects that are a subset of the popular ISO/OSI states that
   are also defined in ITU's X.731 specification [X.731].  Objects are
   defined to capture administrative, operational, and usage states.  In
   addition, there are further state objects defined to provide more
   information for these three basic states.

   Administrative state indicates permission to use or prohibition
   against using the entity and is imposed through the management
   services.

   Operational state indicates whether or not the entity is physically
   installed and working.  Note that unlike the ifOperStatus [RFC2863],
   this operational state is independent of the administrative state.

   Usage state indicates whether or not the entity is in use at a
   specific instance, and if so, whether or not it currently has spare
   capacity to serve additional users.  In the context of this MIB, the
   usage state refers to the ability of an entity to service other
   entities within its containment hierarchy.




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   Alarm state indicates whether or not there are any alarms active
   against the entity.  In addition to those alarm states defined in
   X.731 [X.731], warning and indeterminate status are also defined to
   provide a more complete mapping to the Alarm MIB [RFC3877].

   Standby state indicates whether the entity is currently running as
   hot standby or cold standby or is currently providing service.

   The terms "state" and "status" are used interchangeably in this memo.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.1.  Hierarchical State Management

   Physical entities exist within a containment hierarchy.  Physical
   containment is defined by the entPhysicalContainedIn object[RFC4133].
   This raises some interesting issues not addressed in existing work on
   state management.

   There are two types of state for an entity:

   1) The state of the entity independent of the states of its parents
   and children in its containment hierarchy.  This is often referred to
   as raw state.

   2) The state of the entity, as it may be influenced by the state of
   its parents and children.  This is often referred to as computed
   state.

   All state objects in this memo are raw state.

2.2.  Entity Redundancy

   While this memo is not attempting to address the entire problem space
   around redundancy, the entStateStandby object provides an important
   piece of state information for entities, which helps identify which
   pieces of redundant equipment are currently providing service, and
   which are waiting in either hot or cold standby mode.

2.3.  Physical Entity Users

   There are three ways to define the 'user' of a physical entity

   1. Direct containment in physical hierarchy

   2. Anywhere in physical hierarchy



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   3. As defined by a means outside the scope of this MIB.  This could
   include logical interfaces that could run on a port, software that
   could run on a module, etc.

   Administrative, operational, alarm, and standby state use all three
   definitions of 'user'.  Usage state supports only the concept of
   direct containment to simplify implementations of this object.

2.4.  Physical Class Behavior

   This MIB makes no effort to standardize the behaviors and
   characteristics of the various physical classes [RFC4133], but rather
   how this information is reported.  In looking at real-world products,
   items within the same physical class vary substantially.  The MIB has
   therefore provided guidance on how to support objects where a
   particular instance of a physical class cannot support part or all of
   a particular state.

3.  Relation to Other MIBs

3.1.  Relation to the Interfaces MIB

   The Interfaces MIB [RFC2863] defines the ifAdminStatus object, which
   has states of up, down, and testing, and the ifOperStatus object,
   which has states of up, down, testing, unknown, dormant, notPresent,
   and lowerLayerDown.

   An ifAdminStatus of 'up' is equivalent to setting the entStateAdmin
   object to 'unlocked'.  An ifAdminStatus of 'down' is equivalent to
   setting the entStateAdmin object to either 'locked' or
   'shuttingDown', depending on a system's interpretation of 'down'.

   An ifOperStatus of 'up' is equivalent to an entStateOper value of
   'enabled'.  An ifOperStatus of 'down' due to operational failure is
   equivalent to an entStateOper value of 'disabled'.  An ifOperStatus
   of 'down' due to being administratively disabled is equivalent to an
   entStateAdmin value of 'locked' and an entStateOper value of either
   'enabled' or 'disabled' depending on whether there are any known
   issues that would prevent the entity from becoming operational when
   its entStateAdmin is set to 'unlocked'.  An ifOperStatus of 'unknown'
   is equivalent to an entStateOper value of 'unknown'.  The
   ifOperStatus values of 'testing' and 'dormant' are not explicitly
   supported by this MIB, but the state objects will be able to reflect
   other aspects of the entities' administrative and operational state.
   The ifOperStatus values of 'notPresent' and 'lowerLayerDown' are in
   some ways computed states and so are therefore not supported in this





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   MIB.  They can, though, be computed by examining the states of
   entities within this object's containment hierarchy and other
   available related states.

3.2.  Relation to Alarm MIB

   The entStateAlarm object indicates whether or not there are any
   active alarms against this entity.  If there are active alarms, then
   the alarmActiveTable in the Alarm MIB [RFC3877] should be searched
   for rows whose alarmActiveResourceId matches this entPhysicalIndex.

   Alternatively, if the alarmActiveTable is queried first and an active
   alarm with a value of alarmActiveResourceId that matches this
   entPhysicalIndex is found, then entStateAlarm can be used to quickly
   determine if there are additional active alarms with a different
   severity against this physical entity.

3.3 Relation to Bridge MIB

   For entities of physical type of 'port' that support the
   dot1dStpPortEnable object in the Bridge MIB [RFC4188], a value of
   'enabled' is equivalent to setting the entStateAdmin object to
   'unlocked'.  Setting dot1dStpPortEnable to 'disabled' is equivalent
   to setting the entStateAdmin object to 'locked'.

3.4 Relation to the Host Resources MIB

   The hrDeviceStatus object in the Host Resources MIB [RFC2790]
   provides an operational state for devices.  For entities that
   logically correspond to the concept of a device, a value of 'unknown'
   for hrDeviceStatus corresponds to an entStateOper value of 'unknown'.
   A value of 'running' corresponds to an entStateOper value of
   'enabled'.  A value of 'warning' also corresponds to an entStateOper
   value of 'enabled', but with appropriate bits set in the
   entStateAlarm object to indicate the alarms corresponding to the
   unusual error condition detected.  A value of 'testing' or 'down' is
   equivalent to an entStateOper value of 'disabled'.














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4.  Textual Conventions

   ENTITY-STATE-TC-MIB DEFINITIONS ::= BEGIN

   IMPORTS
      MODULE-IDENTITY, mib-2       FROM SNMPv2-SMI
      TEXTUAL-CONVENTION           FROM SNMPv2-TC;

    entityStateTc MODULE-IDENTITY
        LAST-UPDATED "200511220000Z"
        ORGANIZATION "IETF Entity MIB Working Group"
        CONTACT-INFO
                "General Discussion: entmib@ietf.org
                 To Subscribe:
                 http://www.ietf.org/mailman/listinfo/entmib

                 http://www.ietf.org/html.charters/entmib-charter.html

                 Sharon Chisholm
                 Nortel Networks
                 PO Box 3511 Station C
                 Ottawa, Ont.  K1Y 4H7
                 Canada
                 schishol@nortel.com

                 David T. Perkins
                 548 Qualbrook Ct
                 San Jose, CA 95110
                 USA
                 Phone: 408 394-8702
                 dperkins@snmpinfo.com"
         DESCRIPTION
                "This MIB defines state textual conventions.

                 Copyright (C) The Internet Society 2005.  This version
                 of this MIB module is part of RFC 4268;  see the RFC
                 itself for full legal notices."
         REVISION    "200511220000Z"
         DESCRIPTION
             "Initial version, published as RFC 4268."
        ::= { mib-2 130 }

     EntityAdminState  ::=  TEXTUAL-CONVENTION
       STATUS         current
       DESCRIPTION
            " Represents the various possible administrative states.





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              A value of 'locked' means the resource is administratively
              prohibited from use.  A value of 'shuttingDown' means that
              usage is administratively limited to current instances of
              use.  A value of 'unlocked' means the resource is not
              administratively prohibited from use.  A value of
              'unknown' means that this resource is unable to
              report administrative state."
       SYNTAX         INTEGER
                 {
                 unknown (1),
                 locked (2),
                 shuttingDown (3),
                 unlocked (4)
                 }

     EntityOperState  ::=  TEXTUAL-CONVENTION
       STATUS         current
       DESCRIPTION
            " Represents the possible values of operational states.

              A value of 'disabled' means the resource is totally
              inoperable.  A value of 'enabled' means the resource
              is partially or fully operable.  A value of 'testing'
              means the resource is currently being tested
              and cannot therefore report whether it is operational
              or not.  A value of 'unknown' means that this
              resource is unable to report operational state."
       SYNTAX         INTEGER
                 {
                 unknown (1),
                 disabled (2),
                 enabled (3),
                 testing (4)
                 }

     EntityUsageState  ::=  TEXTUAL-CONVENTION
       STATUS         current
       DESCRIPTION
            " Represents the possible values of usage states.
              A value of 'idle' means the resource is servicing no
              users.  A value of 'active' means the resource is
              currently in use and it has sufficient spare capacity
              to provide for additional users.  A value of 'busy'
              means the resource is currently in use, but it
              currently has no spare capacity to provide for
              additional users.  A value of 'unknown' means
              that this resource is unable to report usage state."
       SYNTAX         INTEGER



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                 {
                 unknown (1),
                 idle (2),
                 active (3),
                 busy (4)
                 }


    EntityAlarmStatus  ::=  TEXTUAL-CONVENTION
       STATUS         current
       DESCRIPTION
          " Represents the possible values of alarm status.
            An Alarm [RFC3877] is a persistent indication
            of an error or warning condition.

            When no bits of this attribute are set, then no active
            alarms are known against this entity and it is not under
            repair.

            When the 'value of underRepair' is set, the resource is
            currently being repaired, which, depending on the
            implementation, may make the other values in this bit
            string not meaningful.

            When the value of 'critical' is set, one or more critical
            alarms are active against the resource.  When the value
            of 'major' is set, one or more major alarms are active
            against the resource.  When the value of 'minor' is set,
            one or more minor alarms are active against the resource.
            When the value of 'warning' is set, one or more warning
            alarms are active against the resource.  When the value
            of 'indeterminate' is set, one or more alarms of whose
            perceived severity cannot be determined are active
            against this resource.

            A value of 'unknown' means that this resource is
            unable to report alarm state."
             SYNTAX         BITS
                {
                unknown (0),
                underRepair (1),
                critical(2),
                major(3),
                minor(4),
                -- The following are not defined in X.733
                warning (5),
                indeterminate (6)
                              }



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     EntityStandbyStatus  ::=  TEXTUAL-CONVENTION
       STATUS         current
       DESCRIPTION
            " Represents the possible values of standby status.

              A value of 'hotStandby' means the resource is not
              providing service, but it will be immediately able to
              take over the role of the resource to be backed up,
              without the need for initialization activity, and will
              contain the same information as the resource to be
              backed up.  A value of 'coldStandy' means that the
              resource is to back up another resource, but will not
              be immediately able to take over the role of a resource
              to be backed up, and will require some initialization
              activity.  A value of 'providingService' means the
              resource is providing service.  A value of
              'unknown' means that this resource is unable to
              report standby state."
             SYNTAX         INTEGER
               {
               unknown (1),
               hotStandby (2),
               coldStandby (3),
               providingService (4)
               }

   END

5.  Definitions

   ENTITY-STATE-MIB DEFINITIONS ::= BEGIN

     IMPORTS
         MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE, mib-2
             FROM SNMPv2-SMI
         DateAndTime
             FROM SNMPv2-TC
         MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
              FROM SNMPv2-CONF
         entPhysicalIndex
              FROM ENTITY-MIB
         EntityAdminState, EntityOperState, EntityUsageState,
         EntityAlarmStatus, EntityStandbyStatus
              FROM ENTITY-STATE-TC-MIB;

     entityStateMIB MODULE-IDENTITY
         LAST-UPDATED "200511220000Z"
         ORGANIZATION "IETF Entity MIB Working Group"



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         CONTACT-INFO
                 " General Discussion: entmib@ietf.org
                   To Subscribe:
                   http://www.ietf.org/mailman/listinfo/entmib

                   http://www.ietf.org/html.charters/entmib-charter.html

                   Sharon Chisholm
                   Nortel Networks
                   PO Box 3511 Station C
                   Ottawa, Ont.  K1Y 4H7
                   Canada
                   schishol@nortel.com

                   David T. Perkins
                   548 Qualbrook Ct
                   San Jose, CA 95110
                   USA
                   Phone: 408 394-8702
                   dperkins@snmpinfo.com
                  "
         DESCRIPTION
             "This MIB defines a state extension to the Entity MIB.

              Copyright (C) The Internet Society 2005.  This version
              of this MIB module is part of RFC 4268; see the RFC
              itself for full legal notices."
         REVISION    "200511220000Z"
         DESCRIPTION
             "Initial version, published as RFC 4268."
         ::= { mib-2 131 }


     -- Entity State Objects

     entStateObjects OBJECT IDENTIFIER ::= { entityStateMIB 1 }

     entStateTable OBJECT-TYPE
      SYNTAX      SEQUENCE OF EntStateEntry
      MAX-ACCESS  not-accessible
      STATUS      current
      DESCRIPTION
          "A table of information about state/status of entities.
           This is a sparse augment of the entPhysicalTable.  Entries
           appear in this table for values of
           entPhysicalClass [RFC4133] that in this implementation
           are able to report any of the state or status stored in
           this table.



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           "
      ::= { entStateObjects 1 }


       entStateEntry OBJECT-TYPE
          SYNTAX      EntStateEntry
          MAX-ACCESS  not-accessible
          STATUS      current
          DESCRIPTION
              "State information about this physical entity."
          INDEX       { entPhysicalIndex }
          ::= { entStateTable 1 }

       EntStateEntry ::= SEQUENCE {
           entStateLastChanged DateAndTime,
           entStateAdmin       EntityAdminState,
           entStateOper        EntityOperState,
           entStateUsage       EntityUsageState,
           entStateAlarm       EntityAlarmStatus,
           entStateStandby     EntityStandbyStatus
          }

     entStateLastChanged OBJECT-TYPE
      SYNTAX      DateAndTime
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
        "The value of this object is the date and
         time when the value of any of entStateAdmin,
         entStateOper, entStateUsage, entStateAlarm,
         or entStateStandby changed for this entity.

         If there has been no change since
         the last re-initialization of the local system,
         this object contains the date and time of
         local system initialization.  If there has been
         no change since the entity was added to the
         local system, this object contains the date and
         time of the insertion."
      ::= { entStateEntry 1 }

   entStateAdmin OBJECT-TYPE
          SYNTAX      EntityAdminState
          MAX-ACCESS  read-write
          STATUS      current
          DESCRIPTION
               "The administrative state for this entity.




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                This object refers to an entities administrative
                permission to service both other entities within
                its containment hierarchy as well other users of
                its services defined by means outside the scope
                of this MIB.

                Setting this object to 'notSupported' will result
                in an 'inconsistentValue' error.  For entities that
                do not support administrative state, all set
                operations will result in an 'inconsistentValue'
                error.

                Some physical entities exhibit only a subset of the
                remaining administrative state values.  Some entities
                cannot be locked, and hence this object exhibits only
                the 'unlocked' state.  Other entities cannot be shutdown
                gracefully, and hence this object does not exhibit the
                'shuttingDown' state.  A value of 'inconsistentValue'
                will be returned if attempts are made to set this
                object to values not supported by its administrative
                model."
          ::= { entStateEntry 2 }

    entStateOper OBJECT-TYPE
          SYNTAX      EntityOperState
          MAX-ACCESS  read-only
          STATUS      current
          DESCRIPTION
              "The operational state for this entity.

               Note that unlike the state model used within the
               Interfaces MIB [RFC2863], this object does not follow
               the administrative state.  An administrative state of
               down does not predict an operational state
               of disabled.

               A value of 'testing' means that entity currently being
               tested and cannot therefore report whether it is
               operational or not.

               A value of 'disabled' means that an entity is totally
               inoperable and unable to provide service both to entities
               within its containment hierarchy, or to other receivers
               of its service as defined in ways outside the scope of
               this MIB.

               A value of 'enabled' means that an entity is fully or
               partially operable and able to provide service both to



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               entities within its containment hierarchy, or to other
               receivers of its service as defined in ways outside the
               scope of this MIB.

               Note that some implementations may not be able to
               accurately report entStateOper while the
               entStateAdmin object has a value other than 'unlocked'.
               In these cases, this object MUST have a value
               of 'unknown'."
          ::= { entStateEntry 3 }

    entStateUsage OBJECT-TYPE
          SYNTAX      EntityUsageState
          MAX-ACCESS  read-only
          STATUS      current
          DESCRIPTION
              "The usage state for this entity.

               This object refers to an entity's ability to service more
               physical entities in a containment hierarchy.  A value
               of 'idle' means this entity is able to contain other
               entities but that no other entity is currently
               contained within this entity.

               A value of 'active' means that at least one entity is
               contained within this entity, but that it could handle
               more.  A value of 'busy' means that the entity is unable
               to handle any additional entities being contained in it.

               Some entities will exhibit only a subset of the
               usage state values.  Entities that are unable to ever
               service any entities within a containment hierarchy will
               always have a usage state of 'busy'.  Some entities will
               only ever be able to support one entity within its
               containment hierarchy and will therefore only exhibit
               values of 'idle' and 'busy'."
             ::= { entStateEntry 4 }

    entStateAlarm OBJECT-TYPE
          SYNTAX      EntityAlarmStatus
          MAX-ACCESS  read-only
          STATUS      current
          DESCRIPTION
              "The alarm status for this entity.  It does not include
               the alarms raised on child components within its
               containment hierarchy.

               A value of 'unknown' means that this entity is



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               unable to report alarm state.  Note that this differs
               from 'indeterminate', which means that alarm state
               is supported and there are alarms against this entity,
               but the severity of some of the alarms is not known.

               If no bits are set, then this entity supports reporting
               of alarms, but there are currently no active alarms
               against this entity."
          ::= { entStateEntry 5 }

   entStateStandby OBJECT-TYPE
          SYNTAX EntityStandbyStatus
          MAX-ACCESS read-only
          STATUS current
          DESCRIPTION
               "The standby status for this entity.

               Some entities will exhibit only a subset of the
               remaining standby state values.  If this entity
               cannot operate in a standby role, the value of this
               object will always be 'providingService'."
     ::= { entStateEntry 6 }

   -- Notifications
    entStateNotifications OBJECT IDENTIFIER ::= { entityStateMIB 0 }

   entStateOperEnabled NOTIFICATION-TYPE
      OBJECTS { entStateAdmin,
                entStateAlarm
              }
      STATUS             current
      DESCRIPTION
              "An entStateOperEnabled notification signifies that the
               SNMP entity, acting in an agent role, has detected that
               the entStateOper object for one of its entities has
               transitioned into the 'enabled' state.

               The entity this notification refers can be identified by
               extracting the entPhysicalIndex from one of the
               variable bindings.  The entStateAdmin and entStateAlarm
               varbinds may be examined to find out additional
               information on the administrative state at the time of
               the operation state change as well as to find out whether
               there were any known alarms against the entity at that
               time that may explain why the physical entity has become
               operationally disabled."
     ::= { entStateNotifications 1 }




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   entStateOperDisabled NOTIFICATION-TYPE
      OBJECTS { entStateAdmin,
                entStateAlarm }
      STATUS             current
      DESCRIPTION
              "An entStateOperDisabled notification signifies that the
               SNMP entity, acting in an agent role, has detected that
               the entStateOper object for one of its entities has
               transitioned into the 'disabled' state.

               The entity this notification refers can be identified by
               extracting the entPhysicalIndex from one of the
               variable bindings.  The entStateAdmin and entStateAlarm
               varbinds may be examined to find out additional
               information on the administrative state at the time of
               the operation state change as well as to find out whether
               there were any known alarms against the entity at that
               time that may affect the physical entity's
               ability to stay operationally enabled."
     ::= { entStateNotifications 2 }

   -- Conformance and Compliance

   entStateConformance OBJECT IDENTIFIER ::= { entityStateMIB 2 }

   entStateCompliances OBJECT IDENTIFIER
                     ::= { entStateConformance 1 }

   entStateCompliance MODULE-COMPLIANCE
         STATUS  current
         DESCRIPTION
             "The compliance statement for systems supporting
             the Entity State MIB."
         MODULE -- this module
             MANDATORY-GROUPS {
              entStateGroup
             }
         GROUP       entStateNotificationsGroup
            DESCRIPTION
                "This group is optional."
         OBJECT entStateAdmin
          MIN-ACCESS  read-only
          DESCRIPTION
              "Write access is not required."
      ::= { entStateCompliances 1 }

   entStateGroups OBJECT IDENTIFIER ::= { entStateConformance 2 }




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   entStateGroup OBJECT-GROUP
      OBJECTS {
              entStateLastChanged,
              entStateAdmin,
              entStateOper,
              entStateUsage,
              entStateAlarm,
              entStateStandby
              }
       STATUS   current
       DESCRIPTION
            "Standard Entity State group."
       ::= { entStateGroups 1}

   entStateNotificationsGroup NOTIFICATION-GROUP
      NOTIFICATIONS {
              entStateOperEnabled,
              entStateOperDisabled
              }
       STATUS   current
       DESCRIPTION
            "Standard Entity State Notification group."
       ::= { entStateGroups 2}

   END

6.  Security Considerations

   The ENTITY-STATE-TC-MIB defined in section 4 does not define any
   management objects.  Instead, it defines a set of textual conventions
   that may be used by other MIB modules to define management objects.
   Meaningful security considerations can only be written in the MIB
   modules that define management objects.  The ENTITY-STATE-TC-MIB has
   therefore no impact on the security of the Internet.

   The ENTITY-STATE-MIB defined in section 5 defines one management
   object -- entStateAdmin -- that has a MAX-ACCESS clause of read-
   write.  The object may be considered sensitive or vulnerable in some
   network environments.  The support for SET operations in a non-secure
   environment without proper protection can have a negative effect on
   network operations.

   Note that setting the entStateAdmin to 'locked' or 'shuttingDown' can
   cause disruption of services ranging from those running on a port to
   those on an entire device, depending on the type of entity.  Access
   to this object should be properly protected.





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   Access to the objects defined in this MIB allows one to figure out
   what the active and standby resources in a network are.  This
   information can be used to optimize attacks on networks so even
   read-only access to this MIB should be properly protected.

   SNMP versions prior to SNMPv3 did not include adequate security.
   Even if the network itself is secure (for example by using IPsec),
   even then, there is no control as to who on the secure network is
   allowed to access and GET/SET (read/change/create/delete) the objects
   in this MIB module.

   It is RECOMMENDED that implementers consider the security features as
   provided by the SNMPv3 framework (see [RFC3410], section 8),
   including full support for the SNMPv3 cryptographic mechanisms (for
   authentication and privacy).

   Further, deployment of SNMP versions prior to SNMPv3 is NOT
   RECOMMENDED.  Instead, it is RECOMMENDED to deploy SNMPv3 and to
   enable cryptographic security.  It is then a customer/operator
   responsibility to ensure that the SNMP entity giving access to an
   instance of this MIB module is properly configured to give access to
   the objects only to those principals (entities) that have legitimate
   rights to indeed GET or SET (change/create/delete) them.

7.  Acknowledgements

   This document is a product of the Entity MIB Working Group.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2578]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
              Rose, M., and S. Waldbusser, "Structure of Management
              Information Version 2 (SMIv2)", STD 58, RFC 2578, April
              1999.

   [RFC2579]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
              Rose, M., and S. Waldbusser, "Textual Conventions for
              SMIv2", STD 58, RFC 2579, April 1999.

   [RFC2580]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
              Rose, M., and S. Waldbusser, "Conformance Statements for
              SMIv2", STD 58, RFC 2580, April 1999.




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   [RFC4133]  Bierman, A. and K. McCloghrie, "Entity MIB (Version 3)",
              RFC 4133, August 2005.

8.2.  Informative References

   [RFC2790]  Waldbusser, S. and P. Grillo, "Host Resources MIB", RFC
              2790, March 2000.

   [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
              MIB using SMIv2", RFC 2863, June 2000.

   [RFC3410]  Case, J., Mundy, R., Partain, D., and B. Stewart,
              "Introduction and Applicability Statements for Internet-
              Standard Management Framework", RFC 3410, December 2002.

   [RFC3877]  Chisholm, S. and D. Romascanu, "Alarm Management
              Information Base (MIB)", RFC 3877, September 2004.

   [RFC4188]  Norseth, K. and E. Bell, "Definitions of Managed Objects
              for Bridges", RFC 4188, September 2005.

   [X.731]    ITU Recommendation X.731, "Information Technology - Open
              Systems Interconnection - System Management: State
              Management Function", 1992.

Authors' Addresses

   Sharon Chisholm
   Nortel Networks
   PO Box 3511, Station C
   Ottawa, Ontario, K1Y 4H7
   Canada

   EMail: schishol@nortel.com


   David T. Perkins
   548 Qualbrook Ct
   San Jose, CA 95110
   USA

   Phone: 408 394-8702
   EMail: dperkins@snmpinfo.com








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