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RFC 1757

 
 
 

Remote Network Monitoring Management Information Base

Part 2 of 4, p. 11 to 37
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5.  Definitions

          RMON-MIB DEFINITIONS ::= BEGIN

              IMPORTS
                  Counter                FROM RFC1155-SMI
                  DisplayString          FROM RFC1158-MIB
                  mib-2                  FROM RFC1213-MIB
                  OBJECT-TYPE            FROM RFC-1212
                  TRAP-TYPE              FROM RFC-1215;

          --  Remote Network Monitoring MIB

              rmon    OBJECT IDENTIFIER ::= { mib-2 16 }


              -- textual conventions

              OwnerString ::= DisplayString
              -- This data type is used to model an administratively
              -- assigned name of the owner of a resource. This
              -- information is taken from the NVT ASCII character
              -- set.  It is suggested that this name contain one or

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              -- more of the following: IP address, management station
              -- name, network manager's name, location, or phone
              -- number.
              -- In some cases the agent itself will be the owner of
              -- an entry.  In these cases, this string shall be set
              -- to a string starting with 'monitor'.
              --
              -- SNMP access control is articulated entirely in terms
              -- of the contents of MIB views; access to a particular
              -- SNMP object instance depends only upon its presence
              -- or absence in a particular MIB view and never upon
              -- its value or the value of related object instances.
              -- Thus, objects of this type afford resolution of
              -- resource contention only among cooperating managers;
              -- they realize no access control function with respect
              -- to uncooperative parties.
              --
              -- By convention, objects with this syntax are declared as
              -- having
              --
              --      SIZE (0..127)

              EntryStatus ::= INTEGER
                         { valid(1),
                           createRequest(2),
                           underCreation(3),
                           invalid(4)
                         }
              -- The status of a table entry.
              --
              -- Setting this object to the value invalid(4) has the
              -- effect of invalidating the corresponding entry.
              -- That is, it effectively disassociates the mapping
              -- identified with said entry.
              -- It is an implementation-specific matter as to whether
              -- the agent removes an invalidated entry from the table.
              -- Accordingly, management stations must be prepared to
              -- receive tabular information from agents that
              -- corresponds to entries currently not in use.  Proper
              -- interpretation of such entries requires examination
              -- of the relevant EntryStatus object.
              --
              -- An existing instance of this object cannot be set to
              -- createRequest(2).  This object may only be set to
              -- createRequest(2) when this instance is created.  When
              -- this object is created, the agent may wish to create
              -- supplemental object instances with default values
              -- to complete a conceptual row in this table.  Because

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              -- the creation of these default objects is entirely at
              -- the option of the agent, the manager must not assume
              -- that any will be created, but may make use of any that
              -- are created. Immediately after completing the create
              -- operation, the agent must set this object to
              -- underCreation(3).
              --
              -- When in the underCreation(3) state, an entry is
              -- allowed to exist in a possibly incomplete, possibly
              -- inconsistent state, usually to allow it to be
              -- modified in mutiple PDUs.  When in this state, an
              -- entry is not fully active.  Entries shall exist in
              -- the underCreation(3) state until the management
              -- station is finished configuring the entry and sets
              -- this object to valid(1) or aborts, setting this
              -- object to invalid(4).  If the agent determines that
              -- an entry has been in the underCreation(3) state for
              -- an abnormally long time, it may decide that the
              -- management station has crashed.  If the agent makes
              -- this decision, it may set this object to invalid(4)
              -- to reclaim the entry.  A prudent agent will
              -- understand that the management station may need to
              -- wait for human input and will allow for that
              -- possibility in its determination of this abnormally
              -- long period.
              --
              -- An entry in the valid(1) state is fully configured and
              -- consistent and fully represents the configuration or
              -- operation such a row is intended to represent.  For
              -- example, it could be a statistical function that is
              -- configured and active, or a filter that is available
              -- in the list of filters processed by the packet capture
              -- process.
              --
              -- A manager is restricted to changing the state of an
              -- entry in the following ways:
              --
              --                       create   under
              --      To:       valid  Request  Creation  invalid
              -- From:
              -- valid             OK       NO        OK       OK
              -- createRequest    N/A      N/A       N/A      N/A
              -- underCreation     OK       NO        OK       OK
              -- invalid           NO       NO        NO       OK
              -- nonExistent       NO       OK        NO       OK
              --
              -- In the table above, it is not applicable to move the
              -- state from the createRequest state to any other

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              -- state because the manager will never find the
              -- variable in that state.  The nonExistent state is
              -- not a value of the enumeration, rather it means that
              -- the entryStatus variable does not exist at all.
              --
              -- An agent may allow an entryStatus variable to change
              -- state in additional ways, so long as the semantics
              -- of the states are followed.  This allowance is made
              -- to ease the implementation of the agent and is made
              -- despite the fact that managers should never
              -- excercise these additional state transitions.


              statistics        OBJECT IDENTIFIER ::= { rmon 1 }
              history           OBJECT IDENTIFIER ::= { rmon 2 }
              alarm             OBJECT IDENTIFIER ::= { rmon 3 }
              hosts             OBJECT IDENTIFIER ::= { rmon 4 }
              hostTopN          OBJECT IDENTIFIER ::= { rmon 5 }
              matrix            OBJECT IDENTIFIER ::= { rmon 6 }
              filter            OBJECT IDENTIFIER ::= { rmon 7 }
              capture           OBJECT IDENTIFIER ::= { rmon 8 }
              event             OBJECT IDENTIFIER ::= { rmon 9 }


          -- The Ethernet Statistics Group
          --
          -- Implementation of the Ethernet Statistics group is
          -- optional.
          --
          -- The ethernet statistics group contains statistics
          -- measured by the probe for each monitored interface on
          -- this device.  These statistics take the form of free
          -- running counters that start from zero when a valid entry
          -- is created.
          --
          -- This group currently has statistics defined only for
          -- Ethernet interfaces.  Each etherStatsEntry contains
          -- statistics for one Ethernet interface.  The probe must
          -- create one etherStats entry for each monitored Ethernet
          -- interface on the device.

          etherStatsTable OBJECT-TYPE
              SYNTAX SEQUENCE OF EtherStatsEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of Ethernet statistics entries."
              ::= { statistics 1 }

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          etherStatsEntry OBJECT-TYPE
              SYNTAX EtherStatsEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A collection of statistics kept for a particular
                  Ethernet interface.  As an example, an instance of the
                  etherStatsPkts object might be named etherStatsPkts.1"
              INDEX { etherStatsIndex }
              ::= { etherStatsTable 1 }

          EtherStatsEntry ::= SEQUENCE {
              etherStatsIndex                    INTEGER (1..65535),
              etherStatsDataSource               OBJECT IDENTIFIER,
              etherStatsDropEvents               Counter,
              etherStatsOctets                   Counter,
              etherStatsPkts                     Counter,
              etherStatsBroadcastPkts            Counter,
              etherStatsMulticastPkts            Counter,
              etherStatsCRCAlignErrors           Counter,
              etherStatsUndersizePkts            Counter,
              etherStatsOversizePkts             Counter,
              etherStatsFragments                Counter,
              etherStatsJabbers                  Counter,
              etherStatsCollisions               Counter,
              etherStatsPkts64Octets             Counter,
              etherStatsPkts65to127Octets        Counter,
              etherStatsPkts128to255Octets       Counter,
              etherStatsPkts256to511Octets       Counter,
              etherStatsPkts512to1023Octets      Counter,
              etherStatsPkts1024to1518Octets     Counter,
              etherStatsOwner                    OwnerString,
              etherStatsStatus                   EntryStatus
          }

          etherStatsIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of this object uniquely identifies this
                  etherStats entry."
              ::= { etherStatsEntry 1 }

          etherStatsDataSource OBJECT-TYPE
              SYNTAX OBJECT IDENTIFIER
              ACCESS read-write
              STATUS mandatory

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              DESCRIPTION
                  "This object identifies the source of the data that
                  this etherStats entry is configured to analyze.  This
                  source can be any ethernet interface on this device.
                  In order to identify a particular interface, this
                  object shall identify the instance of the ifIndex
                  object, defined in RFC 1213 and RFC 1573 [4,6], for
                  the desired interface.  For example, if an entry
                  were to receive data from interface #1, this object
                  would be set to ifIndex.1.

                  The statistics in this group reflect all packets
                  on the local network segment attached to the
                  identified interface.

                  An agent may or may not be able to tell if
                  fundamental changes to the media of the interface
                  have occurred and necessitate an invalidation of
                  this entry.  For example, a hot-pluggable ethernet
                  card could be pulled out and replaced by a
                  token-ring card.  In such a case, if the agent has
                  such knowledge of the change, it is recommended that
                  it invalidate this entry.

                  This object may not be modified if the associated
                  etherStatsStatus object is equal to valid(1)."
              ::= { etherStatsEntry 2 }

          etherStatsDropEvents OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of events in which packets
                  were dropped by the probe due to lack of resources.
                  Note that this number is not necessarily the number of
                  packets dropped; it is just the number of times this
                  condition has been detected."
              ::= { etherStatsEntry 3 }

          etherStatsOctets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of octets of data (including
                  those in bad packets) received on the
                  network (excluding framing bits but including

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                  FCS octets).

                  This object can be used as a reasonable estimate of
                  ethernet utilization.  If greater precision is
                  desired, the etherStatsPkts and etherStatsOctets
                  objects should be sampled before and after a common
                  interval.  The differences in the sampled values are
                  Pkts and Octets, respectively, and the number of
                  seconds in the interval is Interval.  These values
                  are used to calculate the Utilization as follows:

                                   Pkts * (9.6 + 6.4) + (Octets * .8)
                   Utilization = -------------------------------------
                                           Interval * 10,000

                  The result of this equation is the value Utilization
                  which is the percent utilization of the ethernet
                  segment on a scale of 0 to 100 percent."
              ::= { etherStatsEntry 4 }

          etherStatsPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad packets,
                  broadcast packets, and multicast packets) received."
              ::= { etherStatsEntry 5 }

          etherStatsBroadcastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of good packets received that were
                  directed to the broadcast address.  Note that this
                  does not include multicast packets."
              ::= { etherStatsEntry 6 }

          etherStatsMulticastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of good packets received that were
                  directed to a multicast address.  Note that this
                  number does not include packets directed to the
                  broadcast address."

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              ::= { etherStatsEntry 7 }

          etherStatsCRCAlignErrors OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets received that
                  had a length (excluding framing bits, but
                  including FCS octets) of between 64 and 1518
                  octets, inclusive, but but had either a bad
                  Frame Check Sequence (FCS) with an integral
                  number of octets (FCS Error) or a bad FCS with
                  a non-integral number of octets (Alignment Error)."
              ::= { etherStatsEntry 8 }

          etherStatsUndersizePkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets received that were
                  less than 64 octets long (excluding framing bits,
                  but including FCS octets) and were otherwise well
                  formed."
              ::= { etherStatsEntry 9 }

          etherStatsOversizePkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets received that were
                  longer than 1518 octets (excluding framing bits,
                  but including FCS octets) and were otherwise
                  well formed."
              ::= { etherStatsEntry 10 }

          etherStatsFragments OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets received that were less
                  than 64 octets in length (excluding framing bits but
                  including FCS octets) and had either a bad Frame
                  Check Sequence (FCS) with an integral number of
                  octets (FCS Error) or a bad FCS with a non-integral

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                  number of octets (Alignment Error).

                  Note that it is entirely normal for
                  etherStatsFragments to increment.  This is because
                  it counts both runts (which are normal occurrences
                  due to collisions) and noise hits."
              ::= { etherStatsEntry 11 }

          etherStatsJabbers OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets received that were
                  longer than 1518 octets (excluding framing bits,
                  but including FCS octets), and had either a bad
                  Frame Check Sequence (FCS) with an integral number
                  of octets (FCS Error) or a bad FCS with a
                  non-integral number of octets (Alignment Error).

                  Note that this definition of jabber is different
                  than the definition in IEEE-802.3 section 8.2.1.5
                  (10BASE5) and section 10.3.1.4 (10BASE2).  These
                  documents define jabber as the condition where any
                  packet exceeds 20 ms.  The allowed range to detect
                  jabber is between 20 ms and 150 ms."
              ::= { etherStatsEntry 12 }

          etherStatsCollisions OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The best estimate of the total number of collisions
                  on this Ethernet segment.

                  The value returned will depend on the location of
                  the RMON probe. Section 8.2.1.3 (10BASE-5) and
                  section 10.3.1.3 (10BASE-2) of IEEE standard 802.3
                  states that a station must detect a collision, in
                  the receive mode, if three or more stations are
                  transmitting simultaneously.  A repeater port must
                  detect a collision when two or more stations are
                  transmitting simultaneously.  Thus a probe placed on
                  a repeater port could record more collisions than a
                  probe connected to a station on the same segment
                  would.

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                  Probe location plays a much smaller role when
                  considering 10BASE-T.  14.2.1.4 (10BASE-T) of IEEE
                  standard 802.3 defines a collision as the
                  simultaneous presence of signals on the DO and RD
                  circuits (transmitting and receiving at the same
                  time).  A 10BASE-T station can only detect
                  collisions when it is transmitting.  Thus probes
                  placed on a station and a repeater, should report
                  the same number of collisions.

                  Note also that an RMON probe inside a repeater
                  should ideally report collisions between the
                  repeater and one or more other hosts (transmit
                  collisions as defined by IEEE 802.3k) plus receiver
                  collisions observed on any coax segments to which
                  the repeater is connected."
              ::= { etherStatsEntry 13 }

          etherStatsPkts64Octets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad
                  packets) received that were 64 octets in length
                  (excluding framing bits but including FCS octets)."
              ::= { etherStatsEntry 14 }

          etherStatsPkts65to127Octets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad
                  packets) received that were between
                  65 and 127 octets in length inclusive
                  (excluding framing bits but including FCS octets)."
              ::= { etherStatsEntry 15 }

          etherStatsPkts128to255Octets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad
                  packets) received that were between
                  128 and 255 octets in length inclusive
                  (excluding framing bits but including FCS octets)."

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              ::= { etherStatsEntry 16 }

          etherStatsPkts256to511Octets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad
                  packets) received that were between
                  256 and 511 octets in length inclusive
                  (excluding framing bits but including FCS octets)."
              ::= { etherStatsEntry 17 }

          etherStatsPkts512to1023Octets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad
                  packets) received that were between
                  512 and 1023 octets in length inclusive
                  (excluding framing bits but including FCS octets)."
              ::= { etherStatsEntry 18 }

          etherStatsPkts1024to1518Octets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets (including bad
                  packets) received that were between
                  1024 and 1518 octets in length inclusive
                  (excluding framing bits but including FCS octets)."
              ::= { etherStatsEntry 19 }

          etherStatsOwner OBJECT-TYPE
              SYNTAX OwnerString
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The entity that configured this entry and is
                  therefore using the resources assigned to it."
              ::= { etherStatsEntry 20 }

          etherStatsStatus OBJECT-TYPE
              SYNTAX EntryStatus
              ACCESS read-write
              STATUS mandatory

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              DESCRIPTION
                  "The status of this etherStats entry."
              ::= { etherStatsEntry 21 }


          -- The History Control Group

          -- Implementation of the History Control group is optional.
          --
          -- The history control group controls the periodic statistical
          -- sampling of data from various types of networks.  The
          -- historyControlTable stores configuration entries that each
          -- define an interface, polling period, and other parameters.
          -- Once samples are taken, their data is stored in an entry
          -- in a media-specific table.  Each such entry defines one
          -- sample, and is associated with the historyControlEntry that
          -- caused the sample to be taken.  Each counter in the
          -- etherHistoryEntry counts the same event as its
          -- similarly-named counterpart in the etherStatsEntry,
          -- except that each value here is a cumulative sum during a
          -- sampling period.
          --
          -- If the probe keeps track of the time of day, it should
          -- start the first sample of the history at a time such that
          -- when the next hour of the day begins, a sample is
          -- started at that instant.  This tends to make more
          -- user-friendly reports, and enables comparison of reports
          -- from different probes that have relatively accurate time
          -- of day.
          --
          -- The probe is encouraged to add two history control entries
          -- per monitored interface upon initialization that describe
          -- a short term and a long term polling period.  Suggested
          -- parameters are 30 seconds for the short term polling period
          -- and 30 minutes for the long term period.

          historyControlTable OBJECT-TYPE
              SYNTAX SEQUENCE OF HistoryControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of history control entries."
              ::= { history 1 }

          historyControlEntry OBJECT-TYPE
              SYNTAX HistoryControlEntry
              ACCESS not-accessible
              STATUS mandatory

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              DESCRIPTION
                  "A list of parameters that set up a periodic sampling
                  of statistics.  As an example, an instance of the
                  historyControlInterval object might be named
                  historyControlInterval.2"
              INDEX { historyControlIndex }
              ::= { historyControlTable 1 }

          HistoryControlEntry ::= SEQUENCE {
              historyControlIndex             INTEGER (1..65535),
              historyControlDataSource        OBJECT IDENTIFIER,
              historyControlBucketsRequested  INTEGER (1..65535),
              historyControlBucketsGranted    INTEGER (1..65535),
              historyControlInterval          INTEGER (1..3600),
              historyControlOwner             OwnerString,
              historyControlStatus            EntryStatus
          }

          historyControlIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in the
                  historyControl table.  Each such entry defines a
                  set of samples at a particular interval for an
                  interface on the device."
              ::= { historyControlEntry 1 }

          historyControlDataSource OBJECT-TYPE
              SYNTAX OBJECT IDENTIFIER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "This object identifies the source of the data for
                  which historical data was collected and
                  placed in a media-specific table on behalf of this
                  historyControlEntry.  This source can be any
                  interface on this device.  In order to identify
                  a particular interface, this object shall identify
                  the instance of the ifIndex object, defined
                  in  RFC 1213 and RFC 1573 [4,6], for the desired
                  interface.  For example, if an entry were to receive
                  data from interface #1, this object would be set
                  to ifIndex.1.

                  The statistics in this group reflect all packets
                  on the local network segment attached to the

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                  identified interface.

                  An agent may or may not be able to tell if fundamental
                  changes to the media of the interface have occurred
                  and necessitate an invalidation of this entry.  For
                  example, a hot-pluggable ethernet card could be
                  pulled out and replaced by a token-ring card.  In
                  such a case, if the agent has such knowledge of the
                  change, it is recommended that it invalidate this
                  entry.

                  This object may not be modified if the associated
                  historyControlStatus object is equal to valid(1)."
              ::= { historyControlEntry 2 }

          historyControlBucketsRequested OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The requested number of discrete time intervals
                  over which data is to be saved in the part of the
                  media-specific table associated with this
                  historyControlEntry.

                  When this object is created or modified, the probe
                  should set historyControlBucketsGranted as closely to
                  this object as is possible for the particular probe
                  implementation and available resources."
              DEFVAL { 50 }
              ::= { historyControlEntry 3 }

          historyControlBucketsGranted OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of discrete sampling intervals
                  over which data shall be saved in the part of
                  the media-specific table associated with this
                  historyControlEntry.

                  When the associated historyControlBucketsRequested
                  object is created or modified, the probe
                  should set this object as closely to the requested
                  value as is possible for the particular
                  probe implementation and available resources.  The
                  probe must not lower this value except as a result

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                  of a modification to the associated
                  historyControlBucketsRequested object.

                  There will be times when the actual number of
                  buckets associated with this entry is less than
                  the value of this object.  In this case, at the
                  end of each sampling interval, a new bucket will
                  be added to the media-specific table.

                  When the number of buckets reaches the value of
                  this object and a new bucket is to be added to the
                  media-specific table, the oldest bucket associated
                  with this historyControlEntry shall be deleted by
                  the agent so that the new bucket can be added.

                  When the value of this object changes to a value less
                  than the current value, entries are deleted
                  from the media-specific table associated with this
                  historyControlEntry.  Enough of the oldest of these
                  entries shall be deleted by the agent so that their
                  number remains less than or equal to the new value of
                  this object.

                  When the value of this object changes to a value
                  greater than the current value, the number of
                  associated media- specific entries may be allowed to
                  grow."
              ::= { historyControlEntry 4 }

          historyControlInterval OBJECT-TYPE
              SYNTAX INTEGER (1..3600)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The interval in seconds over which the data is
                  sampled for each bucket in the part of the
                  media-specific table associated with this
                  historyControlEntry.  This interval can
                  be set to any number of seconds between 1 and
                  3600 (1 hour).

                  Because the counters in a bucket may overflow at their
                  maximum value with no indication, a prudent manager
                  will take into account the possibility of overflow
                  in any of the associated counters.  It is important
                  to consider the minimum time in which any counter
                  could overflow on a particular media type and set
                  the historyControlInterval object to a value less

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                  than this interval.  This is typically most
                  important for the 'octets' counter in any
                  media-specific table.  For example, on an Ethernet
                  network, the etherHistoryOctets counter could
                  overflow in about one hour at the Ethernet's maximum
                  utilization.

                  This object may not be modified if the associated
                  historyControlStatus object is equal to valid(1)."
              DEFVAL { 1800 }
              ::= { historyControlEntry 5 }

          historyControlOwner OBJECT-TYPE
              SYNTAX OwnerString
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The entity that configured this entry and is
                  therefore using the resources assigned to it."
              ::= { historyControlEntry 6 }

          historyControlStatus OBJECT-TYPE
              SYNTAX EntryStatus
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The status of this historyControl entry.

                  Each instance of the media-specific table associated
                  with this historyControlEntry will be deleted by the
                  agent if this historyControlEntry is not equal to
                  valid(1)."
              ::= { historyControlEntry 7 }


          -- The Ethernet History Group

          -- Implementation of the Ethernet History group is optional.
          --
          -- The Ethernet History group records periodic
          -- statistical samples from a network and stores them
          -- for later retrieval.  Once samples are taken, their
          -- data is stored in an entry in a media-specific
          -- table.  Each such entry defines one sample, and is
          -- associated with the historyControlEntry that caused
          -- the sample to be taken.  This group defines the
          -- etherHistoryTable, for Ethernet networks.
          --

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          etherHistoryTable OBJECT-TYPE
              SYNTAX SEQUENCE OF EtherHistoryEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of Ethernet history entries."
              ::= { history 2 }

          etherHistoryEntry OBJECT-TYPE
              SYNTAX EtherHistoryEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "An historical sample of Ethernet statistics on a
                  particular Ethernet interface.  This sample is
                  associated with the historyControlEntry which set up
                  the parameters for a regular collection of these
                  samples.  As an example, an instance of the
                  etherHistoryPkts object might be named
                  etherHistoryPkts.2.89"
              INDEX { etherHistoryIndex , etherHistorySampleIndex }
              ::= { etherHistoryTable 1 }

          EtherHistoryEntry ::= SEQUENCE {
              etherHistoryIndex                 INTEGER (1..65535),
              etherHistorySampleIndex           INTEGER (1..2147483647),
              etherHistoryIntervalStart         TimeTicks,
              etherHistoryDropEvents            Counter,
              etherHistoryOctets                Counter,
              etherHistoryPkts                  Counter,
              etherHistoryBroadcastPkts         Counter,
              etherHistoryMulticastPkts         Counter,
              etherHistoryCRCAlignErrors        Counter,
              etherHistoryUndersizePkts         Counter,
              etherHistoryOversizePkts          Counter,
              etherHistoryFragments             Counter,
              etherHistoryJabbers               Counter,
              etherHistoryCollisions            Counter,
              etherHistoryUtilization           INTEGER (0..10000)
          }

          etherHistoryIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The history of which this entry is a part.  The
                  history identified by a particular value of this

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                  index is the same history as identified
                  by the same value of historyControlIndex."
              ::= { etherHistoryEntry 1 }

          etherHistorySampleIndex OBJECT-TYPE
              SYNTAX INTEGER (1..2147483647)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies the particular
                  sample this entry represents among all samples
                  associated with the same historyControlEntry.
                  This index starts at 1 and increases by one
                  as each new sample is taken."
              ::= { etherHistoryEntry 2 }

          etherHistoryIntervalStart OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime at the start of the interval
                  over which this sample was measured.  If the probe
                  keeps track of the time of day, it should start
                  the first sample of the history at a time such that
                  when the next hour of the day begins, a sample is
                  started at that instant.  Note that following this
                  rule may require the probe to delay collecting the
                  first sample of the history, as each sample must be
                  of the same interval.  Also note that the sample which
                  is currently being collected is not accessible in this
                  table until the end of its interval."
              ::= { etherHistoryEntry 3 }

          etherHistoryDropEvents OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of events in which packets
                  were dropped by the probe due to lack of resources
                  during this sampling interval.  Note that this number
              is not necessarily the number of packets dropped, it
              is just the number of times this condition has been
              detected."
              ::= { etherHistoryEntry 4 }

          etherHistoryOctets OBJECT-TYPE

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              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of octets of data (including
                  those in bad packets) received on the
                  network (excluding framing bits but including
                  FCS octets)."
              ::= { etherHistoryEntry 5 }

          etherHistoryPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets (including bad packets)
                  received during this sampling interval."
              ::= { etherHistoryEntry 6 }

          etherHistoryBroadcastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets received during this
                  sampling interval that were directed to the
                  broadcast address."
              ::= { etherHistoryEntry 7 }

          etherHistoryMulticastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets received during this
                  sampling interval that were directed to a
                  multicast address.  Note that this number does not
                  include packets addressed to the broadcast address."
              ::= { etherHistoryEntry 8 }

          etherHistoryCRCAlignErrors OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets received during this sampling
                  interval that had a length (excluding framing bits
                  but including FCS octets) between 64 and 1518

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                  octets, inclusive, but had either a bad Frame Check
                  Sequence (FCS) with an integral number of octets
                  (FCS Error) or a bad FCS with a non-integral number
                  of octets (Alignment Error)."
              ::= { etherHistoryEntry 9 }

          etherHistoryUndersizePkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets received during this
                  sampling interval that were less than 64 octets
                  long (excluding framing bits but including FCS
                  octets) and were otherwise well formed."
              ::= { etherHistoryEntry 10 }

          etherHistoryOversizePkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets received during this
                  sampling interval that were longer than 1518
                  octets (excluding framing bits but including
                  FCS octets) but were otherwise well formed."
              ::= { etherHistoryEntry 11 }

          etherHistoryFragments OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The total number of packets received during this
                  sampling interval that were less than 64 octets in
                  length (excluding framing bits but including FCS
                  octets) had either a bad Frame Check Sequence (FCS)
                  with an integral number of octets (FCS Error) or a bad
                  FCS with a non-integral number of octets (Alignment
                  Error).

                  Note that it is entirely normal for
                  etherHistoryFragments to increment.  This is because
                  it counts both runts (which are normal occurrences
                  due to collisions) and noise hits."
              ::= { etherHistoryEntry 12 }

          etherHistoryJabbers OBJECT-TYPE

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              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets received during this
                  sampling interval that were longer than 1518 octets
                  (excluding framing bits but including FCS octets),
                  and  had either a bad Frame Check Sequence (FCS)
                  with an integral number of octets (FCS Error) or
                  a bad FCS with a non-integral number of octets
                  (Alignment Error).

                  Note that this definition of jabber is different
                  than the definition in IEEE-802.3 section 8.2.1.5
                  (10BASE5) and section 10.3.1.4 (10BASE2).  These
                  documents define jabber as the condition where any
                  packet exceeds 20 ms.  The allowed range to detect
                  jabber is between 20 ms and 150 ms."
              ::= { etherHistoryEntry 13 }

          etherHistoryCollisions OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The best estimate of the total number of collisions
                  on this Ethernet segment during this sampling
                  interval.

                  The value returned will depend on the location of
                  the RMON probe. Section 8.2.1.3 (10BASE-5) and
                  section 10.3.1.3 (10BASE-2) of IEEE standard 802.3
                  states that a station must detect a collision, in
                  the receive mode, if three or more stations are
                  transmitting simultaneously.  A repeater port must
                  detect a collision when two or more stations are
                  transmitting simultaneously.  Thus a probe placed on
                  a repeater port could record more collisions than a
                  probe connected to a station on the same segment
                  would.

                  Probe location plays a much smaller role when
                  considering 10BASE-T.  14.2.1.4 (10BASE-T) of IEEE
                  standard 802.3 defines a collision as the
                  simultaneous presence of signals on the DO and RD
                  circuits (transmitting and receiving at the same
                  time).  A 10BASE-T station can only detect
                  collisions when it is transmitting.  Thus probes

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                  placed on a station and a repeater, should report
                  the same number of collisions.

                  Note also that an RMON probe inside a repeater
                  should ideally report collisions between the
                  repeater and one or more other hosts (transmit
                  collisions as defined by IEEE 802.3k) plus receiver
                  collisions observed on any coax segments to which
                  the repeater is connected."
              ::= { etherHistoryEntry 14 }

          etherHistoryUtilization OBJECT-TYPE
              SYNTAX INTEGER (0..10000)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The best estimate of the mean physical layer
                  network utilization on this interface during this
                  sampling interval, in hundredths of a percent."
              ::= { etherHistoryEntry 15 }


          -- The Alarm Group

          -- Implementation of the Alarm group is optional.
          --
          -- The Alarm Group requires the implementation of the Event
          -- group.
          --
          -- The Alarm group periodically takes
          -- statistical samples from variables in the probe and
          -- compares them to thresholds that have been
          -- configured.  The alarm table stores configuration
          -- entries that each define a variable, polling period,
          -- and threshold parameters.  If a sample is found to
          -- cross the threshold values, an event is generated.
          -- Only variables that resolve to an ASN.1 primitive
          -- type of INTEGER (INTEGER, Counter, Gauge, or
          -- TimeTicks) may be monitored in this way.
          --
          -- This function has a hysteresis mechanism to limit
          -- the generation of events.  This mechanism generates
          -- one event as a threshold is crossed in the
          -- appropriate direction.  No more events are generated
          -- for that threshold until the opposite threshold is
          -- crossed.
          --
          -- In the case of a sampling a deltaValue, a probe may

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          -- implement this mechanism with more precision if it
          -- takes a delta sample twice per period, each time
          -- comparing the sum of the latest two samples to the
          -- threshold.  This allows the detection of threshold
          -- crossings that span the sampling boundary.  Note
          -- that this does not require any special configuration
          -- of the threshold value.  It is suggested that probes
          -- implement this more precise algorithm.

          alarmTable OBJECT-TYPE
              SYNTAX SEQUENCE OF AlarmEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of alarm entries."
              ::= { alarm 1 }

          alarmEntry OBJECT-TYPE
              SYNTAX AlarmEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of parameters that set up a periodic checking
                  for alarm conditions.  For example, an instance of the
                  alarmValue object might be named alarmValue.8"
              INDEX { alarmIndex }
              ::= { alarmTable 1 }

          AlarmEntry ::= SEQUENCE {
              alarmIndex                    INTEGER (1..65535),
              alarmInterval                 INTEGER,
              alarmVariable                 OBJECT IDENTIFIER,
              alarmSampleType               INTEGER,
              alarmValue                    INTEGER,
              alarmStartupAlarm             INTEGER,
              alarmRisingThreshold          INTEGER,
              alarmFallingThreshold         INTEGER,
              alarmRisingEventIndex         INTEGER (0..65535),
              alarmFallingEventIndex        INTEGER (0..65535),
              alarmOwner                    OwnerString,
              alarmStatus                   EntryStatus
          }

          alarmIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION

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                  "An index that uniquely identifies an entry in the
                  alarm table.  Each such entry defines a
                  diagnostic sample at a particular interval
                  for an object on the device."
              ::= { alarmEntry 1 }

          alarmInterval OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The interval in seconds over which the data is
                  sampled and compared with the rising and falling
                  thresholds.  When setting this variable, care
                  should be taken in the case of deltaValue
                  sampling - the interval should be set short enough
                  that the sampled variable is very unlikely to
                  increase or decrease by more than 2^31 - 1 during
                  a single sampling interval.

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 2 }

          alarmVariable OBJECT-TYPE
              SYNTAX OBJECT IDENTIFIER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The object identifier of the particular variable to
                  be sampled.  Only variables that resolve to an ASN.1
                  primitive type of INTEGER (INTEGER, Counter, Gauge,
                  or TimeTicks) may be sampled.

                  Because SNMP access control is articulated entirely
                  in terms of the contents of MIB views, no access
                  control mechanism exists that can restrict the value
                  of this object to identify only those objects that
                  exist in a particular MIB view.  Because there is
                  thus no acceptable means of restricting the read
                  access that could be obtained through the alarm
                  mechanism, the probe must only grant write access to
                  this object in those views that have read access to
                  all objects on the probe.

                  During a set operation, if the supplied variable
                  name is not available in the selected MIB view, a
                  badValue error must be returned.  If at any time the

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                  variable name of an established alarmEntry is no
                  longer available in the selected MIB view, the probe
                  must change the status of this alarmEntry to
                  invalid(4).

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 3 }

          alarmSampleType OBJECT-TYPE
              SYNTAX INTEGER {
                  absoluteValue(1),
                  deltaValue(2)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The method of sampling the selected variable and
                  calculating the value to be compared against the
                  thresholds.  If the value of this object is
                  absoluteValue(1), the value of the selected variable
                  will be compared directly with the thresholds at the
                  end of the sampling interval.  If the value of this
                  object is deltaValue(2), the value of the selected
                  variable at the last sample will be subtracted from
                  the current value, and the difference compared with
                  the thresholds.

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 4 }

          alarmValue OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of the statistic during the last sampling
                  period.  For example, if the sample type is
                  deltaValue, this value will be the difference
                  between the samples at the beginning and end of the
                  period.  If the sample type is absoluteValue, this
                  value will be the sampled value at the end of the
                  period.

                  This is the value that is compared with the rising and
                  falling thresholds.

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                  The value during the current sampling period is not
                  made available until the period is completed and will
                  remain available until the next period completes."
              ::= { alarmEntry 5 }

          alarmStartupAlarm OBJECT-TYPE
              SYNTAX INTEGER {
                  risingAlarm(1),
                  fallingAlarm(2),
                  risingOrFallingAlarm(3)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The alarm that may be sent when this entry is first
                  set to valid.  If the first sample after this entry
                  becomes valid is greater than or equal to the
                  risingThreshold and alarmStartupAlarm is equal to
                  risingAlarm(1) or risingOrFallingAlarm(3), then a
                  single rising alarm will be generated.  If the first
                  sample after this entry becomes valid is less than
                  or equal to the fallingThreshold and
                  alarmStartupAlarm is equal to fallingAlarm(2) or
                  risingOrFallingAlarm(3), then a single falling alarm
                  will be generated.

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 6 }

          alarmRisingThreshold OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "A threshold for the sampled statistic.  When the
                  current sampled value is greater than or equal to
                  this threshold, and the value at the last sampling
                  interval was less than this threshold, a single
                  event will be generated.  A single event will also
                  be generated if the first sample after this entry
                  becomes valid is greater than or equal to this
                  threshold and the associated alarmStartupAlarm is
                  equal to risingAlarm(1) or risingOrFallingAlarm(3).

                  After a rising event is generated, another such event
                  will not be generated until the sampled value
                  falls below this threshold and reaches the

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                  alarmFallingThreshold.

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 7 }

          alarmFallingThreshold OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "A threshold for the sampled statistic.  When the
                  current sampled value is less than or equal to this
                  threshold, and the value at the last sampling
                  interval was greater than this threshold, a single
                  event will be generated.  A single event will also
                  be generated if the first sample after this entry
                  becomes valid is less than or equal to this
                  threshold and the associated alarmStartupAlarm is
                  equal to fallingAlarm(2) or risingOrFallingAlarm(3).

                  After a falling event is generated, another such event
                  will not be generated until the sampled value
                  rises above this threshold and reaches the
                  alarmRisingThreshold.

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 8 }

          alarmRisingEventIndex OBJECT-TYPE
              SYNTAX INTEGER (0..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The index of the eventEntry that is
                  used when a rising threshold is crossed.  The
                  eventEntry identified by a particular value of
                  this index is the same as identified by the same value
                  of the eventIndex object.  If there is no
                  corresponding entry in the eventTable, then
                  no association exists.  In particular, if this value
                  is zero, no associated event will be generated, as
                  zero is not a valid event index.

                  This object may not be modified if the associated
                  alarmStatus object is equal to valid(1)."
              ::= { alarmEntry 9 }


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