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.
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
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
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 }
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 }
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.
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.
[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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