Network Working Group                                      S. Waldbusser
Request for Comments: 1757                    Carnegie Mellon University
Obsoletes: 1271                                            February 1995
Category: Standards Track

Remote Network Monitoring Management Information Base

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.

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in TCP/IP-based internets.
   In particular, it defines objects for managing remote network
   monitoring devices.

   1. The Network Management Framework ......................    2
   2. Overview ..............................................    3
   2.1 Remote Network Management Goals ......................    3
   2.2 Textual Conventions ..................................    5
   2.3 Structure of MIB .....................................    5
   2.3.1 The Ethernet Statistics Group ......................    6
   2.3.2 The History Control Group ..........................    6
   2.3.3 The Ethernet History Group .........................    6
   2.3.4 The Alarm Group ....................................    6
   2.3.5 The Host Group .....................................    6
   2.3.6 The HostTopN Group .................................    7
   2.3.7 The Matrix Group ...................................    7
   2.3.8 The Filter Group ...................................    7
   2.3.9 The Packet Capture Group ...........................    7
   2.3.10 The Event Group ...................................    7
   3. Control of Remote Network Monitoring Devices ..........    7
   3.1 Resource Sharing Among Multiple Management Stations ..    8
   3.2 Row Addition Among Multiple Management Stations ......   10
   4. Conventions ...........................................   11
   5. Definitions ...........................................   11
   6. Acknowledgments .......................................   89
   7. References ............................................   89
   8. Security Considerations ...............................   90

9. Author's Address ...................................... 90
10. Appendix: Changes from RFC 1271 ...................... 91

1. The Network Management Framework

   The Internet-standard Network Management Framework consists of three
   components.  They are:

      STD 16, RFC 1155 [1] which defines the SMI, the mechanisms used
      for describing and naming objects for the purpose of management.

      STD 16, RFC 1212 [2] defines a more concise description mechanism,
      which is wholly consistent with the SMI.

      STD 17, RFC 1213 [3] which defines MIB-II, the core set of managed
      objects for the Internet suite of protocols.

      STD 15, RFC 1157 [4] which defines the SNMP, the protocol used for
      network access to managed objects.

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Within a given MIB module,
   objects are defined using RFC 1212's OBJECT-TYPE macro.  At a
   minimum, each object has a name, a syntax, an access-level, and an
   implementation-status.

   The name is an object identifier, an administratively assigned name,
   which specifies an object type.  The object type together with an
   object instance serves to uniquely identify a specific instantiation
   of the object.  For human convenience, we often use a textual string,
   termed the object descriptor, to also refer to the object type.

   The syntax of an object type defines the abstract data structure
   corresponding to that object type.  The ASN.1[5] language is used for
   this purpose.  However, RFC 1155 purposely restricts the ASN.1
   constructs which may be used.  These restrictions are explicitly made
   for simplicity.

   The access-level of an object type defines whether it makes "protocol
   sense" to read and/or write the value of an instance of the object
   type.  (This access-level is independent of any administrative
   authorization policy.)

   The implementation-status of an object type indicates whether the
   object is mandatory, optional, obsolete, or deprecated.

2. Overview

   Remote network monitoring devices, often called monitors or probes,
   are instruments that exist for the purpose of managing a network.
   Often these remote probes are stand-alone devices and devote
   significant internal resources for the sole purpose of managing a
   network.  An organization may employ many of these devices, one per
   network segment, to manage its internet.  In addition, these devices
   may be used for a network management service provider to access a
   client network, often geographically remote.

   The objects defined in this document are intended as an interface
   between an RMON agent and an RMON management application and are not
   intended for direct manipulation by humans.  While some users may
   tolerate the direct display of some of these objects, few will
   tolerate the complexity of manually manipulating objects to
   accomplish row creation.  These functions should be handled by the
   management application.

   While most of the objects in this document are suitable for the
   management of any type of network, there are some which are specific
   to managing Ethernet networks.  These are the objects in the
   etherStatsTable, the etherHistoryTable, and some attributes of the
   filterPktStatus and capturBufferPacketStatus objects.  The design of
   this MIB allows similar objects to be defined for other network
   types.  It is intended that future versions of this document and
   additional documents will define extensions for other network types
   such as Token Ring and FDDI.

2.1. Remote Network Management Goals

              o Offline Operation
                  There are sometimes conditions when a management
                  station will not be in constant contact with its
                  remote monitoring devices.  This is sometimes by
                  design in an attempt to lower communications costs
                  (especially when communicating over a WAN or
                  dialup link), or by accident as network failures
                  affect the communications between the management
                  station and the probe.

                  For this reason, this MIB allows a probe to be
                  configured to perform diagnostics and to collect
                  statistics continuously, even when communication with
                  the management station may not be possible or
                  efficient.  The probe may then attempt to notify
                  the management station when an exceptional condition
                  occurs.  Thus, even in circumstances where

                  communication between management station and probe is
                  not continuous, fault, performance, and configuration
                  information may be continuously accumulated and
                  communicated to the management station conveniently
                  and efficiently.

              o Proactive Monitoring
                  Given the resources available on the monitor, it
                  is potentially helpful for it continuously to run
                  diagnostics and to log network performance.  The
                  monitor is always available at the onset of any
                  failure.  It can notify the management station of the
                  failure and can store historical statistical
                  information about the failure.  This historical
                  information can be played back by the management
                  station in an attempt to perform further diagnosis
                  into the cause of the problem.

              o Problem Detection and Reporting
                  The monitor can be configured to recognize
                  conditions, most notably error conditions, and
                  continuously to check for them.  When one of these
                  conditions occurs, the event may be logged, and
                  management stations may be notified in a number of
                  ways.

              o Value Added Data
                  Because a remote monitoring device represents a
                  network resource dedicated exclusively to network
                  management functions, and because it is located
                  directly on the monitored portion of the network, the
                  remote network monitoring device has the opportunity
                  to add significant value to the data it collects.
                  For instance, by highlighting those hosts on the
                  network that generate the most traffic or errors, the
                  probe can give the management station precisely the
                  information it needs to solve a class of problems.

              o Multiple Managers
                  An organization may have multiple management stations
                  for different units of the organization, for different
                  functions (e.g. engineering and operations), and in an
                  attempt to provide disaster recovery.  Because
                  environments with multiple management stations are
                  common, the remote network monitoring device has to
                  deal with more than own management station,
                  potentially using its resources concurrently.

2.2. Textual Conventions

   Two new data types are introduced as a textual convention in this MIB
   document.  These textual conventions enhance the readability of the
   specification and can ease comparison with other specifications if
   appropriate.  It should be noted that the introduction of the these
   textual conventions has no effect on either the syntax nor the
   semantics of any managed objects.  The use of these is merely an
   artifact of the explanatory method used.  Objects defined in terms of
   one of these methods are always encoded by means of the rules that
   define the primitive type.  Hence, no changes to the SMI or the SNMP
   are necessary to accommodate these textual conventions which are
   adopted merely for the convenience of readers and writers in pursuit
   of the elusive goal of clear, concise, and unambiguous MIB documents.

   The new data types are: OwnerString and EntryStatus.

2.3. Structure of MIB

   The objects are arranged into the following groups:

                  - ethernet statistics

                  - history control

                  - ethernet history

                  - alarm

                  - host

                  - hostTopN

                  - matrix

                  - filter

                  - packet capture

                  - event

   These groups are the basic unit of conformance.  If a remote
   monitoring device implements a group, then it must implement all
   objects in that group.  For example, a managed agent that implements
   the host group must implement the hostControlTable, the hostTable and
   the hostTimeTable.

   All groups in this MIB are optional.  Implementations of this MIB
   must also implement the system and interfaces group of MIB-II [6].
   MIB-II may also mandate the implementation of additional groups.

   These groups are defined to provide a means of assigning object
   identifiers, and to provide a method for managed agents to know which
   objects they must implement.

2.3.1. The Ethernet Statistics Group

   The ethernet statistics group contains statistics measured by the
   probe for each monitored Ethernet interface on this device.  This
   group consists of the etherStatsTable.  In the future other groups
   will be defined for other media types including Token Ring and FDDI.
   These groups should follow the same model as the ethernet statistics
   group.

2.3.2. The History Control Group

   The history control group controls the periodic statistical sampling
   of data from various types of networks.  This group consists of the
   historyControlTable.

2.3.3. The Ethernet History Group

   The ethernet history group records periodic statistical samples from
   an ethernet network and stores them for later retrieval.  This group
   consists of the etherHistoryTable.  In the future, other groups will
   be defined for other media types including Token Ring and FDDI.

2.3.4. The Alarm Group

   The alarm group periodically takes statistical samples from variables
   in the probe and compares them to previously configured thresholds.
   If the monitored variable crosses a threshold, an event is generated.
   A hysteresis mechanism is implemented to limit the generation of
   alarms.  This group consists of the alarmTable and requires the
   implementation of the event group.

2.3.5. The Host Group

   The host group contains statistics associated with each host
   discovered on the network.  This group discovers hosts on the network
   by keeping a list of source and destination MAC Addresses seen in
   good packets promiscuously received from the network.  This group
   consists of the hostControlTable, the hostTable, and the
   hostTimeTable.

2.3.6. The HostTopN Group

   The hostTopN group is used to prepare reports that describe the hosts
   that top a list ordered by one of their statistics.  The available
   statistics are samples of one of their base statistics over an
   interval specified by the management station.  Thus, these statistics
   are rate based.  The management station also selects how many such
   hosts are reported.  This group consists of the hostTopNControlTable
   and the hostTopNTable, and requires the implementation of the host
   group.

2.3.7. The Matrix Group

   The matrix group stores statistics for conversations between sets of
   two addresses.  As the device detects a new conversation, it creates
   a new entry in its tables.  This group consists of the
   matrixControlTable, the matrixSDTable and the matrixDSTable.

2.3.8. The Filter Group

   The filter group allows packets to be matched by a filter equation.
   These matched packets form a data stream that may be captured or may
   generate events.  This group consists of the filterTable and the
   channelTable.

2.3.9. The Packet Capture Group

   The Packet Capture group allows packets to be captured after they
   flow through a channel.  This group consists of the
   bufferControlTable and the captureBufferTable, and requires the
   implementation of the filter group.

2.3.10. The Event Group

   The event group controls the generation and notification of events
   from this device.  This group consists of the eventTable and the
   logTable.

3. Control of Remote Network Monitoring Devices

   Due to the complex nature of the available functions in these
   devices, the functions often need user configuration.  In many cases,
   the function requires parameters to be set up for a data collection
   operation.  The operation can proceed only after these parameters are
   fully set up.

   Many functional groups in this MIB have one or more tables in which
   to set up control parameters, and one or more data tables in which to
   place the results of the operation.  The control tables are typically
   read-write in nature, while the data tables are typically read-only.
   Because the parameters in the control table often describe resulting
   data in the data table, many of the parameters can be modified only
   when the control entry is invalid.  Thus, the method for modifying
   these parameters is to invalidate the control entry, causing its
   deletion and the deletion of any associated data entries, and then
   create a new control entry with the proper parameters.  Deleting the
   control entry also gives a convenient method for reclaiming the
   resources used by the associated data.

   Some objects in this MIB provide a mechanism to execute an action on
   the remote monitoring device.  These objects may execute an action as
   a result of a change in the state of the object.  For those objects
   in this MIB, a request to set an object to the same value as it
   currently holds would thus cause no action to occur.

   To facilitate control by multiple managers, resources have to be
   shared among the managers.  These resources are typically the memory
   and computation resources that a function requires.

3.1. Resource Sharing Among Multiple Management Stations

   When multiple management stations wish to use functions that compete
   for a finite amount of resources on a device, a method to facilitate
   this sharing of resources is required.  Potential conflicts include:

              o Two management stations wish to simultaneously use
                resources that together would exceed the capability of
                the device.
              o A management station uses a significant amount of
                resources for a long period of time.
              o A management station uses resources and then crashes,
                forgetting to free the resources so others may
                use them.

   A mechanism is provided for each management station initiated
   function in this MIB to avoid these conflicts and to help resolve
   them when they occur.  Each function has a label identifying the
   initiator (owner) of the function.  This label is set by the
   initiator to provide for the following possibilities:

              o A management station may recognize resources it owns
                and no longer needs.
              o A network operator can find the management station that
                owns the resource and negotiate for it to be freed.

              o A network operator may decide to unilaterally free
                resources another network operator has reserved.
              o Upon initialization, a management station may recognize
                resources it had reserved in the past.  With this
                information it may free the resources if it no longer
                needs them.

   Management stations and probes should support any format of the owner
   string dictated by the local policy of the organization.  It is
   suggested that this name contain one or more of the following: IP
   address, management station name, network manager's name, location,
   or phone number.  This information will help users to share the
   resources more effectively.

   There is often default functionality that the device or the
   administrator of the probe (often the network administrator) wishes
   to set up.  The resources associated with this functionality are then
   owned by the device itself or by the network administrator, and are
   intended to be long-lived.  In this case, the device or the
   administrator will set the relevant owner object to a string starting
   with 'monitor'.  Indiscriminate modification of the monitor-owned
   configuration by network management stations is discouraged.  In
   fact, a network management station should only modify these objects
   under the direction of the administrator of the probe.

   Resources on a probe are scarce and are typically allocated when
   control rows are created by an application.  Since many applications
   may be using a probe simultaneously, indiscriminate allocation of
   resources to particular applications is very likely to cause resource
   shortages in the probe.

   When a network management station wishes to utilize a function in a
   monitor, it is encouraged to first scan the control table of that
   function to find an instance with similar parameters to share.  This
   is especially true for those instances owned by the monitor, which
   can be assumed to change infrequently.  If a management station
   decides to share an instance owned by another management station, it
   should understand that the management station that owns the instance
   may indiscriminately modify or delete it.

   It should be noted that a management application should have the most
   trust in a monitor-owned row because it should be changed very
   infrequently.  A row owned by the management application is less
   long-lived because a network administrator is more likely to re-
   assign resources from a row that is in use by one user than from a
   monitor-owned row that is potentially in use by many users.  A row
   owned by another application would be even less long-lived because
   the other application may delete or modify that row completely at its

discretion.

3.2. Row Addition Among Multiple Management Stations

   The addition of new rows is achieved using the method described in
   RFC 1212 [9].  In this MIB, rows are often added to a table in order
   to configure a function.  This configuration usually involves
   parameters that control the operation of the function.  The agent
   must check these parameters to make sure they are appropriate given
   restrictions defined in this MIB as well as any implementation
   specific restrictions such as lack of resources.  The agent
   implementor may be confused as to when to check these parameters and
   when to signal to the management station that the parameters are
   invalid.  There are two opportunities:

              o When the management station sets each parameter object.

              o When the management station sets the entry status object
                to valid.

   If the latter is chosen, it would be unclear to the management
   station which of the several parameters was invalid and caused the
   badValue error to be emitted.  Thus, wherever possible, the
   implementor should choose the former as it will provide more
   information to the management station.

   A problem can arise when multiple management stations attempt to set
   configuration information simultaneously using SNMP.  When this
   involves the addition of a new conceptual row in the same control
   table, the managers may collide, attempting to create the same entry.
   To guard against these collisions, each such control entry contains a
   status object with special semantics that help to arbitrate among the
   managers.  If an attempt is made with the row addition mechanism to
   create such a status object and that object already exists, an error
   is returned.  When more than one manager simultaneously attempts to
   create the same conceptual row, only the first will succeed.  The
   others will receive an error.

   When a manager wishes to create a new control entry, it needs to
   choose an index for that row.  It may choose this index in a variety
   of ways, hopefully minimizing the chances that the index is in use by
   another manager.  If the index is in use, the mechanism mentioned
   previously will guard against collisions.  Examples of schemes to
   choose index values include random selection or scanning the control
   table looking for the first unused index.  Because index values may
   be any valid value in the range and they are chosen by the manager,
   the agent must allow a row to be created with any unused index value
   if it has the resources to create a new row.

   Some tables in this MIB reference other tables within this MIB.  When
   creating or deleting entries in these tables, it is generally
   allowable for dangling references to exist.  There is no defined
   order for creating or deleting entries in these tables.

4. Conventions

   The following conventions are used throughout the RMON MIB and its
   companion documents.

   Good Packets

   Good packets are error-free packets that have a valid frame length.
   For example, on Ethernet, good packets are error-free packets that
   are between 64 octets long and 1518 octets long.  They follow the
   form defined in IEEE 802.3 section 3.2.all.

   Bad Packets

   Bad packets are packets that have proper framing and are therefore
   recognized as packets, but contain errors within the packet or have
   an invalid length.  For example, on Ethernet, bad packets have a
   valid preamble and SFD, but have a bad CRC, or are either shorter
   than 64 octets or longer than 1518 octets.

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

              -- 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

              -- 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

              -- 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 }

          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

              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

                  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."

              ::= { 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

                  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.

                  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)."

              ::= { 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

              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

              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

                  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

                  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

                  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.
          --

          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

                  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

              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

                  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

              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

                  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

          -- 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

                  "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

                  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.

                  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

                  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 }

          alarmFallingEventIndex OBJECT-TYPE
              SYNTAX INTEGER (0..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The index of the eventEntry that is
                  used when a falling 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 10 }

          alarmOwner 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."
              ::= { alarmEntry 11 }

          alarmStatus OBJECT-TYPE
              SYNTAX EntryStatus
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The status of this alarm entry."
              ::= { alarmEntry 12 }

          -- The Host Group

          -- Implementation of the Host group is optional.
          --
          -- The host group discovers new hosts on the network by
          -- keeping a list of source and destination MAC Addresses seen
          -- in good packets.  For each of these addresses, the host
          -- group keeps a set of statistics.  The hostControlTable
          -- controls which interfaces this function is performed on,
          -- and contains some information about the process.  On
          -- behalf of each hostControlEntry, data is collected on an

          -- interface and placed in both the hostTable and the
          -- hostTimeTable.  If the monitoring device finds itself
          -- short of resources, it may delete entries as needed.  It
          -- is suggested that the device delete the least recently
          -- used entries first.

          -- The hostTable contains entries for each address
          -- discovered on a particular interface.  Each entry
          -- contains statistical data about that host.  This table is
          -- indexed by the MAC address of the host, through which a
          -- random access may be achieved.

          -- The hostTimeTable contains data in the same format as the
          -- hostTable, and must contain the same set of hosts, but is
          -- indexed using hostTimeCreationOrder rather than
          -- hostAddress.
          -- The hostTimeCreationOrder is an integer which reflects
          -- the relative order in which a particular entry was
          -- discovered and thus inserted into the table.  As this
          -- order, and thus the index, is among those entries
          -- currently in the table, the index for a particular entry
          -- may change if an (earlier) entry is deleted.  Thus the
          -- association between hostTimeCreationOrder and
          -- hostTimeEntry may be broken at any time.

          -- The hostTimeTable has two important uses.  The first is the
          -- fast download of this potentially large table.  Because the
          -- index of this table runs from 1 to the size of the table,
          -- inclusive, its values are predictable.  This allows very
          -- efficient packing of variables into SNMP PDU's and allows
          -- a table transfer to have multiple packets outstanding.
          -- These benefits increase transfer rates tremendously.

          -- The second use of the hostTimeTable is the efficient
          -- discovery by the management station of new entries added
          -- to the table. After the management station has downloaded
          -- the entire table, it knows that new entries will be added
          -- immediately after the end of the current table.  It can
          -- thus detect new entries there and retrieve them easily.

          -- Because the association between hostTimeCreationOrder and
          -- hostTimeEntry may be broken at any time, the management
          -- station must monitor the related hostControlLastDeleteTime
          -- object.  When the management station thus detects a
          -- deletion, it must assume that any such associations have
          --- been broken, and invalidate any it has stored locally.
          -- This includes restarting any download of the
          -- hostTimeTable that may have been in progress, as well as

          -- rediscovering the end of the hostTimeTable so that it may
          -- detect new entries.  If the management station does not
          -- detect the broken association, it may continue to refer
          -- to a particular host by its creationOrder while
          -- unwittingly retrieving the data associated with another
          -- host entirely.  If this happens while downloading the
          -- host table, the management station may fail to download
          -- all of the entries in the table.

          hostControlTable OBJECT-TYPE
              SYNTAX SEQUENCE OF HostControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of host table control entries."
              ::= { hosts 1 }

          hostControlEntry OBJECT-TYPE
              SYNTAX HostControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of parameters that set up the discovery of
                  hosts on a particular interface and the collection
                  of statistics about these hosts.  For example, an
                  instance of the hostControlTableSize object might be
                  named hostControlTableSize.1"
              INDEX { hostControlIndex }
              ::= { hostControlTable 1 }

          HostControlEntry ::= SEQUENCE {
              hostControlIndex            INTEGER (1..65535),
              hostControlDataSource       OBJECT IDENTIFIER,
              hostControlTableSize        INTEGER,
              hostControlLastDeleteTime   TimeTicks,
              hostControlOwner            OwnerString,
              hostControlStatus           EntryStatus
          }

          hostControlIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in the
                  hostControl table.  Each such entry defines
                  a function that discovers hosts on a particular
                  interface and places statistics about them in the

                  hostTable and the hostTimeTable on behalf of this
                  hostControlEntry."
              ::= { hostControlEntry 1 }

          hostControlDataSource OBJECT-TYPE
              SYNTAX OBJECT IDENTIFIER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "This object identifies the source of the data for
                  this instance of the host function.  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
                  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
                  hostControlStatus object is equal to valid(1)."
              ::= { hostControlEntry 2 }

          hostControlTableSize OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of hostEntries in the hostTable and the
                  hostTimeTable associated with this hostControlEntry."
              ::= { hostControlEntry 3 }

          hostControlLastDeleteTime OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only

              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime when the last entry
                  was deleted from the portion of the hostTable
                  associated with this hostControlEntry.  If no
                  deletions have occurred, this value shall be zero."
              ::= { hostControlEntry 4 }

          hostControlOwner 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."
              ::= { hostControlEntry 5 }

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

                  If this object is not equal to valid(1), all
                  associated entries in the hostTable, hostTimeTable,
                  and the hostTopNTable shall be deleted by the
                  agent."
              ::= { hostControlEntry 6 }

          hostTable OBJECT-TYPE
              SYNTAX SEQUENCE OF HostEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of host entries."
              ::= { hosts 2 }

          hostEntry OBJECT-TYPE
              SYNTAX HostEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A collection of statistics for a particular host
                  that has been discovered on an interface of this
                  device.  For example, an instance of the
                  hostOutBroadcastPkts object might be named
                  hostOutBroadcastPkts.1.6.8.0.32.27.3.176"

              INDEX { hostIndex, hostAddress }
              ::= { hostTable 1 }

          HostEntry ::= SEQUENCE {
              hostAddress             OCTET STRING,
              hostCreationOrder       INTEGER (1..65535),
              hostIndex               INTEGER (1..65535),
              hostInPkts              Counter,
              hostOutPkts             Counter,
              hostInOctets            Counter,
              hostOutOctets           Counter,
              hostOutErrors           Counter,
              hostOutBroadcastPkts    Counter,
              hostOutMulticastPkts    Counter
          }

          hostAddress OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The physical address of this host."
              ::= { hostEntry 1 }

          hostCreationOrder OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that defines the relative ordering of
                  the creation time of hosts captured for a
                  particular hostControlEntry.  This index shall
                  be between 1 and N, where N is the value of
                  the associated hostControlTableSize.  The ordering
                  of the indexes is based on the order of each entry's
                  insertion into the table, in which entries added
                  earlier have a lower index value than entries added
                  later.

                  It is important to note that the order for a
                  particular entry may change as an (earlier) entry
                  is deleted from the table.  Because this order may
                  change, management stations should make use of the
                  hostControlLastDeleteTime variable in the
                  hostControlEntry associated with the relevant
                  portion of the hostTable.  By observing
                  this variable, the management station may detect
                  the circumstances where a previous association

                  between a value of hostCreationOrder
                  and a hostEntry may no longer hold."
              ::= { hostEntry 2 }

          hostIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The set of collected host statistics of which
                  this entry is a part.  The set of hosts
                  identified by a particular value of this
                  index is associated with the hostControlEntry
                  as identified by the same value of hostControlIndex."
              ::= { hostEntry 3 }

          hostInPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets transmitted to this
                  address since it was added to the hostTable."
              ::= { hostEntry 4 }

          hostOutPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets, including bad packets,
                  transmitted by this address since it was added
                  to the hostTable."
              ::= { hostEntry 5 }

          hostInOctets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of octets transmitted to this address
                  since it was added to the hostTable (excluding
                  framing bits but including FCS octets), except for
                  those octets in bad packets."
              ::= { hostEntry 6 }

          hostOutOctets OBJECT-TYPE
              SYNTAX Counter

              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of octets transmitted by this address
                  since it was added to the hostTable (excluding
                  framing bits but including FCS octets), including
                  those octets in bad packets."
              ::= { hostEntry 7 }

          hostOutErrors OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of bad packets transmitted by this address
                  since this host was added to the hostTable."
              ::= { hostEntry 8 }

          hostOutBroadcastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets transmitted by this
                  address that were directed to the broadcast address
                  since this host was added to the hostTable."
              ::= { hostEntry 9 }

          hostOutMulticastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets transmitted by this
                  address that were directed to a multicast address
                  since this host was added to the hostTable.
                  Note that this number does not include packets
                  directed to the broadcast address."
              ::= { hostEntry 10 }

          -- host Time Table

          hostTimeTable OBJECT-TYPE
              SYNTAX SEQUENCE OF HostTimeEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of time-ordered host table entries."

              ::= { hosts 3 }

          hostTimeEntry OBJECT-TYPE
              SYNTAX HostTimeEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A collection of statistics for a particular host
                  that has been discovered on an interface of this
                  device.  This collection includes the relative
                  ordering of the creation time of this object.  For
                  example, an instance of the hostTimeOutBroadcastPkts
                  object might be named
                  hostTimeOutBroadcastPkts.1.687"
              INDEX { hostTimeIndex, hostTimeCreationOrder }
              ::= { hostTimeTable 1 }

          HostTimeEntry ::= SEQUENCE {
              hostTimeAddress              OCTET STRING,
              hostTimeCreationOrder        INTEGER (1..65535),
              hostTimeIndex                INTEGER (1..65535),
              hostTimeInPkts               Counter,
              hostTimeOutPkts              Counter,
              hostTimeInOctets             Counter,
              hostTimeOutOctets            Counter,
              hostTimeOutErrors            Counter,
              hostTimeOutBroadcastPkts     Counter,
              hostTimeOutMulticastPkts     Counter
          }

          hostTimeAddress OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The physical address of this host."
              ::= { hostTimeEntry 1 }

          hostTimeCreationOrder OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in
                  the hostTime table among those entries associated
                  with the same hostControlEntry.  This index shall
                  be between 1 and N, where N is the value of
                  the associated hostControlTableSize.  The ordering

                  of the indexes is based on the order of each entry's
                  insertion into the table, in which entries added
                  earlier have a lower index value than entries added
                  later. Thus the management station has the ability to
                  learn of new entries added to this table without
                  downloading the entire table.

                  It is important to note that the index for a
                  particular entry may change as an (earlier) entry
                  is deleted from the table.  Because this order may
                  change, management stations should make use of the
                  hostControlLastDeleteTime variable in the
                  hostControlEntry associated with the relevant
                  portion of the hostTimeTable.  By observing
                  this variable, the management station may detect
                  the circumstances where a download of the table
                  may have missed entries, and where a previous
                  association between a value of hostTimeCreationOrder
                  and a hostTimeEntry may no longer hold."
              ::= { hostTimeEntry 2 }

          hostTimeIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The set of collected host statistics of which
                  this entry is a part.  The set of hosts
                  identified by a particular value of this
                  index is associated with the hostControlEntry
                  as identified by the same value of hostControlIndex."
              ::= { hostTimeEntry 3 }

          hostTimeInPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets transmitted to this
                  address since it was added to the hostTimeTable."
              ::= { hostTimeEntry 4 }

          hostTimeOutPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of god packets transmitted by this

                  address since it was added to the hostTimeTable."
              ::= { hostTimeEntry 5 }

          hostTimeInOctets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of octets transmitted to this address
                  since it was added to the hostTimeTable (excluding
                  framing bits but including FCS octets), except for
                  those octets in bad packets."
              ::= { hostTimeEntry 6 }

          hostTimeOutOctets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of octets transmitted by this address
                  since it was added to the hostTimeTable (excluding
                  framing bits but including FCS octets), including
                  those octets in bad packets."
              ::= { hostTimeEntry 7 }

          hostTimeOutErrors OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of bad packets transmitted by this address
                  since this host was added to the hostTimeTable."
              ::= { hostTimeEntry 8 }

          hostTimeOutBroadcastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of good packets transmitted by this
                  address that were directed to the broadcast address
                  since this host was added to the hostTimeTable."
              ::= { hostTimeEntry 9 }

          hostTimeOutMulticastPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory

              DESCRIPTION
                  "The number of good packets transmitted by this
                  address that were directed to a multicast address
                  since this host was added to the hostTimeTable.
                  Note that this number does not include packets
                  directed to the broadcast address."
              ::= { hostTimeEntry 10 }

          -- The Host Top "N" Group

          -- Implementation of the Host Top N group is optional.
          --
          -- The Host Top N group requires the implementation of the
          -- host group.
          --
          -- The Host Top N group is used to prepare reports that
          -- describe the hosts that top a list ordered by one of
          -- their statistics.
          -- The available statistics are samples of one of their
          -- base statistics, over an interval specified by the
          -- management station.  Thus, these statistics are rate
          -- based.  The management station also selects how many such
          -- hosts are reported.

          -- The hostTopNControlTable is used to initiate the
          -- generation of such a report.  The management station
          -- may select the parameters of such a report, such as
          -- which interface, which statistic, how many hosts,
          -- and the start and stop times of the sampling.  When
          -- the report is prepared, entries are created in the
          -- hostTopNTable associated with the relevant
          -- hostTopNControlEntry.  These entries are static for
          -- each report after it has been prepared.

          hostTopNControlTable OBJECT-TYPE
              SYNTAX SEQUENCE OF HostTopNControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of top N host control entries."
              ::= { hostTopN 1 }

          hostTopNControlEntry OBJECT-TYPE
              SYNTAX HostTopNControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION

                  "A set of parameters that control the creation of a
                  report of the top N hosts according to several
                  metrics.  For example, an instance of the
                  hostTopNDuration object might be named
                  hostTopNDuration.3"
              INDEX { hostTopNControlIndex }
              ::= { hostTopNControlTable 1 }

          HostTopNControlEntry ::= SEQUENCE {
              hostTopNControlIndex    INTEGER (1..65535),
              hostTopNHostIndex       INTEGER (1..65535),
              hostTopNRateBase        INTEGER,
              hostTopNTimeRemaining   INTEGER,
              hostTopNDuration        INTEGER,
              hostTopNRequestedSize   INTEGER,
              hostTopNGrantedSize     INTEGER,
              hostTopNStartTime       TimeTicks,
              hostTopNOwner           OwnerString,
              hostTopNStatus          EntryStatus
          }

          hostTopNControlIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry
                  in the hostTopNControl table.  Each such
                  entry defines one top N report prepared for
                  one interface."
              ::= { hostTopNControlEntry 1 }

          hostTopNHostIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The host table for which a top N report will be
                  prepared on behalf of this entry.  The host table
                  identified by a particular value of this index is
                  associated with the same host table as identified by
                  the same value of hostIndex.

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

          hostTopNRateBase OBJECT-TYPE

              SYNTAX INTEGER {
                      hostTopNInPkts(1),
                      hostTopNOutPkts(2),
                      hostTopNInOctets(3),
                      hostTopNOutOctets(4),
                      hostTopNOutErrors(5),
                      hostTopNOutBroadcastPkts(6),
                      hostTopNOutMulticastPkts(7)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The variable for each host that the hostTopNRate
                  variable is based upon.

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

          hostTopNTimeRemaining OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The number of seconds left in the report currently
                  being collected.  When this object is modified by
                  the management station, a new collection is started,
                  possibly aborting a currently running report.  The
                  new value is used as the requested duration of this
                  report, which is loaded into the associated
                  hostTopNDuration object.

                  When this object is set to a non-zero value, any
                  associated hostTopNEntries shall be made
                  inaccessible by the monitor.  While the value of
                  this object is non-zero, it decrements by one per
                  second until it reaches zero.  During this time, all
                  associated hostTopNEntries shall remain
                  inaccessible.  At the time that this object
                  decrements to zero, the report is made accessible in
                  the hostTopNTable.  Thus, the hostTopN table needs
                  to be created only at the end of the collection
                  interval."
              DEFVAL { 0 }
              ::= { hostTopNControlEntry 4 }

          hostTopNDuration OBJECT-TYPE
              SYNTAX INTEGER

              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of seconds that this report has collected
                  during the last sampling interval, or if this
                  report is currently being collected, the number
                  of seconds that this report is being collected
                  during this sampling interval.

                  When the associated hostTopNTimeRemaining object is
                  set, this object shall be set by the probe to the
                  same value and shall not be modified until the next
                  time the hostTopNTimeRemaining is set.

                  This value shall be zero if no reports have been
                  requested for this hostTopNControlEntry."
              DEFVAL { 0 }
              ::= { hostTopNControlEntry 5 }

          hostTopNRequestedSize OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The maximum number of hosts requested for the top N
                  table.

                  When this object is created or modified, the probe
                  should set hostTopNGrantedSize as closely to this
                  object as is possible for the particular probe
                  implementation and available resources."
              DEFVAL { 10 }
              ::= { hostTopNControlEntry 6 }

          hostTopNGrantedSize OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The maximum number of hosts in the top N table.

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

                  Hosts with the highest value of hostTopNRate shall be
                  placed in this table in decreasing order of this rate
                  until there is no more room or until there are no more
                  hosts."
              ::= { hostTopNControlEntry 7 }

          hostTopNStartTime OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime when this top N report was
                  last started.  In other words, this is the time that
                  the associated hostTopNTimeRemaining object was
                  modified to start the requested report."
              ::= { hostTopNControlEntry 8 }

          hostTopNOwner 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."
              ::= { hostTopNControlEntry 9 }

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

                  If this object is not equal to valid(1), all
                  associated hostTopNEntries shall be deleted by the
                  agent."
              ::= { hostTopNControlEntry 10 }

          hostTopNTable OBJECT-TYPE
              SYNTAX SEQUENCE OF HostTopNEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of top N host entries."
              ::= { hostTopN 2 }

          hostTopNEntry OBJECT-TYPE
              SYNTAX HostTopNEntry

              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A set of statistics for a host that is part of a
                  top N report.  For example, an instance of the
                  hostTopNRate object might be named
                  hostTopNRate.3.10"
              INDEX { hostTopNReport, hostTopNIndex }
              ::= { hostTopNTable 1 }

          HostTopNEntry ::= SEQUENCE {
              hostTopNReport                INTEGER (1..65535),
              hostTopNIndex                 INTEGER (1..65535),
              hostTopNAddress               OCTET STRING,
              hostTopNRate                  INTEGER
          }

          hostTopNReport OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "This object identifies the top N report of which
                  this entry is a part.  The set of hosts
                  identified by a particular value of this
                  object is part of the same report as identified
                  by the same value of the hostTopNControlIndex object."
              ::= { hostTopNEntry 1 }

          hostTopNIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in
                  the hostTopN table among those in the same report.
                  This index is between 1 and N, where N is the
                  number of entries in this table.  Increasing values
                  of hostTopNIndex shall be assigned to entries with
                  decreasing values of hostTopNRate until index N
                  is assigned to the entry with the lowest value of
                  hostTopNRate or there are no more hostTopNEntries."
              ::= { hostTopNEntry 2 }

          hostTopNAddress OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory

              DESCRIPTION
                  "The physical address of this host."
              ::= { hostTopNEntry 3 }

          hostTopNRate OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The amount of change in the selected variable
                  during this sampling interval.  The selected
                  variable is this host's instance of the object
                  selected by hostTopNRateBase."
              ::= { hostTopNEntry 4 }

          -- The Matrix Group

          -- Implementation of the Matrix group is optional.
          --
          -- The Matrix group consists of the matrixControlTable,
          -- matrixSDTable and the matrixDSTable.  These tables
          -- store statistics for a particular conversation
          -- between two addresses.  As the device detects a new
          -- conversation, including those to a non-unicast
          -- address, it creates a new entry in both of the
          -- matrix tables.  It must only create new entries
          -- based on information received in good packets.  If
          -- the monitoring device finds itself short of
          -- resources, it may delete entries as needed.  It is
          -- suggested that the device delete the least recently
          -- used entries first.

          matrixControlTable OBJECT-TYPE
              SYNTAX SEQUENCE OF MatrixControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of information entries for the
                  traffic matrix on each interface."
              ::= { matrix 1 }

          matrixControlEntry OBJECT-TYPE
              SYNTAX MatrixControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "Information about a traffic matrix on a particular

                  interface.  For example, an instance of the
                  matrixControlLastDeleteTime object might be named
                  matrixControlLastDeleteTime.1"
              INDEX { matrixControlIndex }
              ::= { matrixControlTable 1 }

          MatrixControlEntry ::= SEQUENCE {
              matrixControlIndex           INTEGER (1..65535),
              matrixControlDataSource      OBJECT IDENTIFIER,
              matrixControlTableSize       INTEGER,
              matrixControlLastDeleteTime  TimeTicks,
              matrixControlOwner           OwnerString,
              matrixControlStatus          EntryStatus
          }

          matrixControlIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in the
                  matrixControl table.  Each such entry defines
                  a function that discovers conversations on a
                  particular interface and places statistics about
                  them in the matrixSDTable and the matrixDSTable on
                  behalf of this matrixControlEntry."
              ::= { matrixControlEntry 1 }

          matrixControlDataSource OBJECT-TYPE
              SYNTAX OBJECT IDENTIFIER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "This object identifies the source of
                  the data from which this entry creates a traffic
                  matrix. 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
                  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
                  matrixControlStatus object is equal to valid(1)."
              ::= { matrixControlEntry 2 }

          matrixControlTableSize OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of matrixSDEntries in the matrixSDTable
                  for this interface.  This must also be the value of
                  the number of entries in the matrixDSTable for this
                  interface."
              ::= { matrixControlEntry 3 }

          matrixControlLastDeleteTime OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime when the last entry
                  was deleted from the portion of the matrixSDTable
                  or matrixDSTable associated with this
                  matrixControlEntry. If no deletions have occurred,
                  this value shall be zero."
              ::= { matrixControlEntry 4 }

          matrixControlOwner 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."
              ::= { matrixControlEntry 5 }

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

              DESCRIPTION
                  "The status of this matrixControl entry.

                  If this object is not equal to valid(1), all
                  associated entries in the matrixSDTable and the
                  matrixDSTable shall be deleted by the agent."
              ::= { matrixControlEntry 6 }

          matrixSDTable OBJECT-TYPE
              SYNTAX SEQUENCE OF MatrixSDEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of traffic matrix entries indexed by
                  source and destination MAC address."
              ::= { matrix 2 }

          matrixSDEntry OBJECT-TYPE
              SYNTAX MatrixSDEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A collection of statistics for communications between
                  two addresses on a particular interface.  For example,
                  an instance of the matrixSDPkts object might be named
                  matrixSDPkts.1.6.8.0.32.27.3.176.6.8.0.32.10.8.113"
              INDEX { matrixSDIndex,
                      matrixSDSourceAddress, matrixSDDestAddress }
              ::= { matrixSDTable 1 }

          MatrixSDEntry ::= SEQUENCE {
              matrixSDSourceAddress       OCTET STRING,
              matrixSDDestAddress         OCTET STRING,
              matrixSDIndex               INTEGER (1..65535),
              matrixSDPkts                Counter,
              matrixSDOctets              Counter,
              matrixSDErrors              Counter
          }

          matrixSDSourceAddress OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The source physical address."
              ::= { matrixSDEntry 1 }

          matrixSDDestAddress OBJECT-TYPE

              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The destination physical address."
              ::= { matrixSDEntry 2 }

          matrixSDIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The set of collected matrix statistics of which
                  this entry is a part.  The set of matrix statistics
                  identified by a particular value of this index
                  is associated with the same matrixControlEntry
                  as identified by the same value of
                  matrixControlIndex."
              ::= { matrixSDEntry 3 }

          matrixSDPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets transmitted from the source
                  address to the destination address (this number
                  includes bad packets)."
              ::= { matrixSDEntry 4 }

          matrixSDOctets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of octets (excluding framing bits but
                  including FCS octets) contained in all packets
                  transmitted from the source address to the
                  destination address."
              ::= { matrixSDEntry 5 }

          matrixSDErrors OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of bad packets transmitted from
                  the source address to the destination address."

              ::= { matrixSDEntry 6 }

          -- Traffic matrix tables from destination to source

          matrixDSTable OBJECT-TYPE
              SYNTAX SEQUENCE OF MatrixDSEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of traffic matrix entries indexed by
                  destination and source MAC address."
              ::= { matrix 3 }

          matrixDSEntry OBJECT-TYPE
              SYNTAX MatrixDSEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A collection of statistics for communications between
                  two addresses on a particular interface.  For example,
                  an instance of the matrixSDPkts object might be named
                  matrixSDPkts.1.6.8.0.32.10.8.113.6.8.0.32.27.3.176"
              INDEX { matrixDSIndex,
                      matrixDSDestAddress, matrixDSSourceAddress }
              ::= { matrixDSTable 1 }

          MatrixDSEntry ::= SEQUENCE {
              matrixDSSourceAddress       OCTET STRING,
              matrixDSDestAddress         OCTET STRING,
              matrixDSIndex               INTEGER (1..65535),
              matrixDSPkts                Counter,
              matrixDSOctets              Counter,
              matrixDSErrors              Counter
          }

          matrixDSSourceAddress OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The source physical address."
              ::= { matrixDSEntry 1 }

          matrixDSDestAddress OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory

              DESCRIPTION
                  "The destination physical address."
              ::= { matrixDSEntry 2 }

          matrixDSIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The set of collected matrix statistics of which
                  this entry is a part.  The set of matrix statistics
                  identified by a particular value of this index
                  is associated with the same matrixControlEntry
                  as identified by the same value of
                  matrixControlIndex."
              ::= { matrixDSEntry 3 }

          matrixDSPkts OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets transmitted from the source
                  address to the destination address (this number
                  includes bad packets)."
              ::= { matrixDSEntry 4 }

          matrixDSOctets OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of octets (excluding framing bits
                  but including FCS octets) contained in all packets
                  transmitted from the source address to the
                  destination address."
              ::= { matrixDSEntry 5 }

          matrixDSErrors OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of bad packets transmitted from
                  the source address to the destination address."
              ::= { matrixDSEntry 6 }

          -- The Filter Group

          -- Implementation of the Filter group is optional.
          --
          -- The Filter group allows packets to be captured with an
          -- arbitrary filter expression.  A logical data and
          -- event stream or "channel" is formed by the packets
          -- that match the filter expression.
          --
          -- This filter mechanism allows the creation of an arbitrary
          -- logical expression with which to filter packets.  Each
          -- filter associated with a channel is OR'ed with the others.
          -- Within a filter, any bits checked in the data and status
          -- are AND'ed with respect to other bits in the same filter.
          -- The NotMask also allows for checking for inequality.
          -- Finally, the channelAcceptType object allows for
          -- inversion of the whole equation.
          --
          -- If a management station wishes to receive a trap to alert
          -- it that new packets have been captured and are available
          -- for download, it is recommended that it set up an alarm
          -- entry that monitors the value of the relevant
          -- channelMatches instance.
          --
          -- The channel can be turned on or off, and can also
          -- generate events when packets pass through it.

          filterTable OBJECT-TYPE
              SYNTAX SEQUENCE OF FilterEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of packet filter entries."
              ::= { filter 1 }

          filterEntry OBJECT-TYPE
              SYNTAX FilterEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A set of parameters for a packet filter applied on a
                  particular interface.  As an example, an instance of
                  the filterPktData object might be named
                  filterPktData.12"
              INDEX { filterIndex }
              ::= { filterTable 1 }

          FilterEntry ::= SEQUENCE {
              filterIndex                 INTEGER (1..65535),
              filterChannelIndex          INTEGER (1..65535),
              filterPktDataOffset         INTEGER,
              filterPktData               OCTET STRING,
              filterPktDataMask           OCTET STRING,
              filterPktDataNotMask        OCTET STRING,
              filterPktStatus             INTEGER,
              filterPktStatusMask         INTEGER,
              filterPktStatusNotMask      INTEGER,
              filterOwner                 OwnerString,
              filterStatus                EntryStatus
          }

          filterIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry
                  in the filter table.  Each such entry defines
                  one filter that is to be applied to every packet
                  received on an interface."
              ::= { filterEntry 1 }

          filterChannelIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "This object identifies the channel of which this
                  filter is a part.  The filters identified by a
                  particular value of this object are associated with
                  the same channel as identified by the same value of
                  the channelIndex object."
              ::= { filterEntry 2 }

          filterPktDataOffset OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The offset from the beginning of each packet where
                  a match of packet data will be attempted.  This offset
                  is measured from the point in the physical layer
                  packet after the framing bits, if any.  For example,
                  in an Ethernet frame, this point is at the beginning
                  of the destination MAC address.

                  This object may not be modified if the associated
                  filterStatus object is equal to valid(1)."
              DEFVAL { 0 }
              ::= { filterEntry 3 }

          filterPktData OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The data that is to be matched with the input
                  packet.  For each packet received, this filter and
                  the accompanying filterPktDataMask and
                  filterPktDataNotMask will be adjusted for the
                  offset.  The only bits relevant to this match
                  algorithm are those that have the corresponding
                  filterPktDataMask bit equal to one.  The following
                  three rules are then applied to every packet:

                  (1) If the packet is too short and does not have data
                      corresponding to part of the filterPktData, the
                      packet will fail this data match.

                  (2) For each relevant bit from the packet with the
                      corresponding filterPktDataNotMask bit set to
                      zero, if the bit from the packet is not equal to
                      the corresponding bit from the filterPktData,
                      then the packet will fail this data match.

                  (3) If for every relevant bit from the packet with the
                      corresponding filterPktDataNotMask bit set to one,
                      the bit from the packet is equal to the
                      corresponding bit from the filterPktData, then
                      the packet will fail this data match.

                  Any packets that have not failed any of the three
                  matches above have passed this data match.  In
                  particular, a zero length filter will match any
                  packet.

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

          filterPktDataMask OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-write
              STATUS mandatory

              DESCRIPTION
                  "The mask that is applied to the match process.
                  After adjusting this mask for the offset, only those
                  bits in the received packet that correspond to bits
                  set in this mask are relevant for further processing
                  by the match algorithm.  The offset is applied to
                  filterPktDataMask in the same way it is applied to the
                  filter.  For the purposes of the matching algorithm,
                  if the associated filterPktData object is longer
                  than this mask, this mask is conceptually extended
                  with '1' bits until it reaches the length of the
                  filterPktData object.

                  This object may not be modified if the associated
                  filterStatus object is equal to valid(1)."
              ::= { filterEntry 5 }

          filterPktDataNotMask OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The inversion mask that is applied to the match
                  process.  After adjusting this mask for the offset,
                  those relevant bits in the received packet that
                  correspond to bits cleared in this mask must all be
                  equal to their corresponding bits in the
                  filterPktData object for the packet to be accepted.
                  In addition, at least one of those relevant bits in
                  the received packet that correspond to bits set in
                  this mask must be different to its corresponding bit
                  in the filterPktData object.

                  For the purposes of the matching algorithm, if the
                  associated filterPktData object is longer than this
                  mask, this mask is conceptually extended with '0'
                  bits until it reaches the length of the
                  filterPktData object.

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

          filterPktStatus OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION

                  "The status that is to be matched with the input
                  packet.  The only bits relevant to this match
                  algorithm are those that have the corresponding
                  filterPktStatusMask bit equal to one.  The following
                  two rules are then applied to every packet:

                  (1) For each relevant bit from the packet status
                      with the corresponding filterPktStatusNotMask bit
                      set to zero, if the bit from the packet status is
                      not equal to the corresponding bit from the
                      filterPktStatus, then the packet will fail this
                      status match.

                  (2) If for every relevant bit from the packet status
                      with the corresponding filterPktStatusNotMask bit
                      set to one, the bit from the packet status is
                      equal to the corresponding bit from the
                      filterPktStatus, then the packet will fail this
                      status match.

                  Any packets that have not failed either of the two
                  matches above have passed this status match.  In
                  particular, a zero length status filter will match any
                  packet's status.

                  The value of the packet status is a sum.  This sum
                  initially takes the value zero.  Then, for each
                  error, E, that has been discovered in this packet,
                  2 raised to a value representing E is added to the
                  sum. The errors and the bits that represent them are
                  dependent on the media type of the interface that
                  this channel is receiving packets from.

                  The errors defined for a packet captured off of an
                  Ethernet interface are as follows:

                      bit #    Error
                          0    Packet is longer than 1518 octets
                          1    Packet is shorter than 64 octets
                          2    Packet experienced a CRC or Alignment
                               error

                  For example, an Ethernet fragment would have a
                  value of 6 (2^1 + 2^2).

                  As this MIB is expanded to new media types, this
                  object will have other media-specific errors
                  defined.

                  For the purposes of this status matching algorithm,
                  if the packet status is longer than this
                  filterPktStatus object, this object is conceptually
                  extended with '0' bits until it reaches the size of
                  the packet status.

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

          filterPktStatusMask OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The mask that is applied to the status match
                  process.  Only those bits in the received packet
                  that correspond to bits set in this mask are
                  relevant for further processing by the status match
                  algorithm.  For the purposes of the matching
                  algorithm, if the associated filterPktStatus object
                  is longer than this mask, this mask is conceptually
                  extended with '1' bits until it reaches the size of
                  the filterPktStatus.  In addition, if a packet
                  status is longer than this mask, this mask is
                  conceptually extended with '0' bits until it reaches
                  the size of the packet status.

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

          filterPktStatusNotMask OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The inversion mask that is applied to the status
                  match process.  Those relevant bits in the received
                  packet status that correspond to bits cleared in
                  this mask must all be equal to their corresponding
                  bits in the filterPktStatus object for the packet to
                  be accepted.  In addition, at least one of those
                  relevant bits in the received packet status that
                  correspond to bits set in this mask must be
                  different to its corresponding bit in the
                  filterPktStatus object for the packet to be
                  accepted.

                  For the purposes of the matching algorithm, if the
                  associated filterPktStatus object or a packet status
                  is longer than this mask, this mask is conceptually
                  extended with '0' bits until it reaches the longer
                  of the lengths of the filterPktStatus object and the
                  packet status.

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

          filterOwner 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."
              ::= { filterEntry 10 }

          filterStatus OBJECT-TYPE
              SYNTAX EntryStatus
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The status of this filter entry."
              ::= { filterEntry 11 }

          channelTable OBJECT-TYPE
              SYNTAX SEQUENCE OF ChannelEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of packet channel entries."
              ::= { filter 2 }

          channelEntry OBJECT-TYPE
              SYNTAX ChannelEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A set of parameters for a packet channel applied on a
                  particular interface.  As an example, an instance of
                  the channelMatches object might be named
                  channelMatches.3"
              INDEX { channelIndex }
              ::= { channelTable 1 }

          ChannelEntry ::= SEQUENCE {
              channelIndex               INTEGER (1..65535),
              channelIfIndex             INTEGER (1..65535),
              channelAcceptType          INTEGER,
              channelDataControl         INTEGER,
              channelTurnOnEventIndex    INTEGER (0..65535),
              channelTurnOffEventIndex   INTEGER (0..65535),
              channelEventIndex          INTEGER (0..65535),
              channelEventStatus         INTEGER,
              channelMatches             Counter,
              channelDescription         DisplayString (SIZE (0..127)),
              channelOwner               OwnerString,
              channelStatus              EntryStatus
          }

          channelIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in the
                  channel table.  Each such entry defines one channel,
                  a logical data and event stream.

                  It is suggested that before creating a channel, an
                  application should scan all instances of the
                  filterChannelIndex object to make sure that there
                  are no pre-existing filters that would be
                  inadvertently be linked to the channel."
              ::= { channelEntry 1 }

          channelIfIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The value of this object uniquely identifies the
                  interface on this remote network monitoring device
                  to which the associated filters are applied to allow
                  data into this channel.  The interface identified by
                  a particular value of this object is the same
                  interface as identified by the same value of the
                  ifIndex object, defined in RFC 1213 and RFC 1573
                  [4,6].

                  The filters in this group are applied to 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
                  channelStatus object is equal to valid(1)."
              ::= { channelEntry 2 }

          channelAcceptType OBJECT-TYPE
              SYNTAX INTEGER {
                  acceptMatched(1),
                  acceptFailed(2)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "This object controls the action of the filters
                  associated with this channel.  If this object is equal
                  to acceptMatched(1), packets will be accepted to this
                  channel if they are accepted by both the packet data
                  and packet status matches of an associated filter.  If
                  this object is equal to acceptFailed(2), packets will
                  be accepted to this channel only if they fail either
                  the packet data match or the packet status match of
                  each of the associated filters.

                  In particular, a channel with no associated filters
                  will match no packets if set to acceptMatched(1)
                  case and will match all packets in the
                  acceptFailed(2) case.

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

          channelDataControl OBJECT-TYPE
              SYNTAX INTEGER {
                  on(1),
                  off(2)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION

                  "This object controls the flow of data through this
                  channel.  If this object is on(1), data, status and
                  events flow through this channel.  If this object is
                  off(2), data, status and events will not flow
                  through this channel."
              DEFVAL { off }
              ::= { channelEntry 4 }

          channelTurnOnEventIndex OBJECT-TYPE
              SYNTAX INTEGER (0..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The value of this object identifies the event
                  that is configured to turn the associated
                  channelDataControl from off to on when the event is
                  generated.  The event identified by a particular value
                  of this object is the same event as identified by the
                  same value of the eventIndex object.  If there is no
                  corresponding entry in the eventTable, then no
                  association exists.  In fact, if no event is intended
                  for this channel, channelTurnOnEventIndex must be
                  set to zero, a non-existent event index.

                  This object may not be modified if the associated
                  channelStatus object is equal to valid(1)."
              ::= { channelEntry 5 }

          channelTurnOffEventIndex OBJECT-TYPE
              SYNTAX INTEGER (0..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The value of this object identifies the event
                  that is configured to turn the associated
                  channelDataControl from on to off when the event is
                  generated.  The event identified by a particular value
                  of this object is the same event as identified by the
                  same value of the eventIndex object.  If there is no
                  corresponding entry in the eventTable, then no
                  association exists.  In fact, if no event is intended
                  for this channel, channelTurnOffEventIndex must be
                  set to zero, a non-existent event index.

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

          channelEventIndex OBJECT-TYPE
              SYNTAX INTEGER (0..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The value of this object identifies the event
                  that is configured to be generated when the
                  associated channelDataControl is on and a packet
                  is matched.  The event identified by a particular
                  value of this object is the same event as identified
                  by the same value of the eventIndex object.  If
                  there is no corresponding entry in the eventTable,
                  then no association exists.  In fact, if no event is
                  intended for this channel, channelEventIndex must be
                  set to zero, a non-existent event index.

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

          channelEventStatus OBJECT-TYPE
              SYNTAX INTEGER {
                  eventReady(1),
                  eventFired(2),
                  eventAlwaysReady(3)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The event status of this channel.

                  If this channel is configured to generate events
                  when packets are matched, a means of controlling
                  the flow of those events is often needed.  When
                  this object is equal to eventReady(1), a single
                  event may be generated, after which this object
                  will be set by the probe to eventFired(2).  While
                  in the eventFired(2) state, no events will be
                  generated until the object is modified to
                  eventReady(1) (or eventAlwaysReady(3)).  The
                  management station can thus easily respond to a
                  notification of an event by re-enabling this object.

                  If the management station wishes to disable this
                  flow control and allow events to be generated
                  at will, this object may be set to
                  eventAlwaysReady(3).  Disabling the flow control
                  is discouraged as it can result in high network

                  traffic or other performance problems."
              DEFVAL { eventReady }
              ::= { channelEntry 8 }

          channelMatches OBJECT-TYPE
              SYNTAX Counter
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of times this channel has matched a
                  packet. Note that this object is updated even when
                  channelDataControl is set to off."
              ::= { channelEntry 9 }

          channelDescription OBJECT-TYPE
              SYNTAX DisplayString (SIZE (0..127))
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "A comment describing this channel."
              ::= { channelEntry 10 }

          channelOwner 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."
              ::= { channelEntry 11 }

          channelStatus OBJECT-TYPE
              SYNTAX EntryStatus
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The status of this channel entry."
              ::= { channelEntry 12 }

          -- The Packet Capture Group

          -- Implementation of the Packet Capture group is optional.
          --
          -- The Packet Capture Group requires implementation of the
          -- Filter Group.
          --
          -- The Packet Capture group allows packets to be captured

          -- upon a filter match.  The bufferControlTable controls
          -- the captured packets output from a channel that is
          -- associated with it.  The captured packets are placed
          -- in entries in the captureBufferTable.  These entries are
          -- associated with the bufferControlEntry on whose behalf they
          -- were stored.

          bufferControlTable OBJECT-TYPE
              SYNTAX SEQUENCE OF BufferControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of buffers control entries."
              ::= { capture 1 }

          bufferControlEntry OBJECT-TYPE
              SYNTAX BufferControlEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A set of parameters that control the collection of
                  a stream of packets that have matched filters.  As
                  an example, an instance of the
                  bufferControlCaptureSliceSize object might be named
                  bufferControlCaptureSliceSize.3"
              INDEX { bufferControlIndex }
              ::= { bufferControlTable 1 }

          BufferControlEntry ::= SEQUENCE {
              bufferControlIndex                INTEGER (1..65535),
              bufferControlChannelIndex         INTEGER (1..65535),
              bufferControlFullStatus           INTEGER,
              bufferControlFullAction           INTEGER,
              bufferControlCaptureSliceSize     INTEGER,
              bufferControlDownloadSliceSize    INTEGER,
              bufferControlDownloadOffset       INTEGER,
              bufferControlMaxOctetsRequested   INTEGER,
              bufferControlMaxOctetsGranted     INTEGER,
              bufferControlCapturedPackets      INTEGER,
              bufferControlTurnOnTime           TimeTicks,
              bufferControlOwner                OwnerString,
              bufferControlStatus               EntryStatus
          }

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

              DESCRIPTION
                  "An index that uniquely identifies an entry
                  in the bufferControl table.  The value of this
                  index shall never be zero.  Each such
                  entry defines one set of packets that is
                  captured and controlled by one or more filters."
              ::= { bufferControlEntry 1 }

          bufferControlChannelIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "An index that identifies the channel that is the
                  source of packets for this bufferControl table.
                  The channel identified by a particular value of this
                  index is the same as identified by the same value of
                  the channelIndex object.

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

          bufferControlFullStatus OBJECT-TYPE
              SYNTAX INTEGER {
                      spaceAvailable(1),
                      full(2)
              }
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "This object shows whether the buffer has room to
                  accept new packets or if it is full.

                  If the status is spaceAvailable(1), the buffer is
                  accepting new packets normally.  If the status is
                  full(2) and the associated bufferControlFullAction
                  object is wrapWhenFull, the buffer is accepting new
                  packets by deleting enough of the oldest packets
                  to make room for new ones as they arrive.  Otherwise,
                  if the status is full(2) and the
                  bufferControlFullAction object is lockWhenFull,
                  then the buffer has stopped collecting packets.

                  When this object is set to full(2) the probe must
                  not later set it to spaceAvailable(1) except in the
                  case of a significant gain in resources such as
                  an increase of bufferControlOctetsGranted.  In

                  particular, the wrap-mode action of deleting old
                  packets to make room for newly arrived packets
                  must not affect the value of this object."
              ::= { bufferControlEntry 3 }

          bufferControlFullAction OBJECT-TYPE
              SYNTAX INTEGER {
                      lockWhenFull(1),
                      wrapWhenFull(2)    -- FIFO
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "Controls the action of the buffer when it
                  reaches the full status.  When in the lockWhenFull(1)
                  state and a packet is added to the buffer that
                  fills the buffer, the bufferControlFullStatus will
                  be set to full(2) and this buffer will stop capturing
                  packets."
              ::= { bufferControlEntry 4 }

          bufferControlCaptureSliceSize OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The maximum number of octets of each packet
                  that will be saved in this capture buffer.
                  For example, if a 1500 octet packet is received by
                  the probe and this object is set to 500, then only
                  500 octets of the packet will be stored in the
                  associated capture buffer.  If this variable is set
                  to 0, the capture buffer will save as many octets
                  as is possible.

                  This object may not be modified if the associated
                  bufferControlStatus object is equal to valid(1)."
              DEFVAL { 100 }
              ::= { bufferControlEntry 5 }

          bufferControlDownloadSliceSize OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The maximum number of octets of each packet
                  in this capture buffer that will be returned in
                  an SNMP retrieval of that packet.  For example,

                  if 500 octets of a packet have been stored in the
                  associated capture buffer, the associated
                  bufferControlDownloadOffset is 0, and this
                  object is set to 100, then the captureBufferPacket
                  object that contains the packet will contain only
                  the first 100 octets of the packet.

                  A prudent manager will take into account possible
                  interoperability or fragmentation problems that may
                  occur if the download slice size is set too large.
                  In particular, conformant SNMP implementations are not
                  required to accept messages whose length exceeds 484
                  octets, although they are encouraged to support larger
                  datagrams whenever feasible."
              DEFVAL { 100 }
              ::= { bufferControlEntry 6 }

          bufferControlDownloadOffset OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The offset of the first octet of each packet
                  in this capture buffer that will be returned in
                  an SNMP retrieval of that packet.  For example,
                  if 500 octets of a packet have been stored in the
                  associated capture buffer and this object is set to
                  100, then the captureBufferPacket object that
                  contains the packet will contain bytes starting
                  100 octets into the packet."
              DEFVAL { 0 }
              ::= { bufferControlEntry 7 }

          bufferControlMaxOctetsRequested OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The requested maximum number of octets to be
                  saved in this captureBuffer, including any
                  implementation-specific overhead. If this variable
                  is set to -1, the capture buffer will save as many
                  octets as is possible.

                  When this object is created or modified, the probe
                  should set bufferControlMaxOctetsGranted as closely
                  to this object as is possible for the particular probe
                  implementation and available resources.  However, if

                  the object has the special value of -1, the probe
                  must set bufferControlMaxOctetsGranted to -1."
              DEFVAL { -1 }
              ::= { bufferControlEntry 8 }

          bufferControlMaxOctetsGranted OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The maximum number of octets that can be
                  saved in this captureBuffer, including overhead.
                  If this variable is -1, the capture buffer will save
                  as many octets as possible.

                  When the bufferControlMaxOctetsRequested 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.
                  However, if the request object has the special value
                  of -1, the probe must set this object to -1.
                  The probe must not lower this value except as a result
                  of a modification to the associated
                  bufferControlMaxOctetsRequested object.

                  When this maximum number of octets is reached
                  and a new packet is to be added to this
                  capture buffer and the corresponding
                  bufferControlFullAction is set to wrapWhenFull(2),
                  enough of the oldest packets associated with this
                  capture buffer shall be deleted by the agent so
                  that the new packet can be added.  If the
                  corresponding bufferControlFullAction is set to
                  lockWhenFull(1), the new packet shall be discarded.
                  In either case, the probe must set
                  bufferControlFullStatus to full(2).

                  When the value of this object changes to a value less
                  than the current value, entries are deleted from
                  the captureBufferTable associated with this
                  bufferControlEntry.  Enough of the
                  oldest of these captureBufferEntries shall be
                  deleted by the agent so that the number of octets
                  used 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 captureBufferEntries may be allowed to
                  grow."
              ::= { bufferControlEntry 9 }

          bufferControlCapturedPackets OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of packets currently in this
                  captureBuffer."
              ::= { bufferControlEntry 10 }

          bufferControlTurnOnTime OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime when this capture buffer was
                  first turned on."
              ::= { bufferControlEntry 11 }

          bufferControlOwner 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."
              ::= { bufferControlEntry 12 }

          bufferControlStatus OBJECT-TYPE
              SYNTAX EntryStatus
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The status of this buffer Control Entry."
              ::= { bufferControlEntry 13 }

          captureBufferTable OBJECT-TYPE
              SYNTAX SEQUENCE OF CaptureBufferEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of packets captured off of a channel."
              ::= { capture 2 }

          captureBufferEntry OBJECT-TYPE
              SYNTAX CaptureBufferEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A packet captured off of an attached network.  As an
                  example, an instance of the captureBufferPacketData
                  object might be named captureBufferPacketData.3.1783"
              INDEX { captureBufferControlIndex, captureBufferIndex }
              ::= { captureBufferTable 1 }

          CaptureBufferEntry ::= SEQUENCE {
              captureBufferControlIndex   INTEGER (1..65535),
              captureBufferIndex          INTEGER (1..2147483647),
              captureBufferPacketID       INTEGER,
              captureBufferPacketData     OCTET STRING,
              captureBufferPacketLength   INTEGER,
              captureBufferPacketTime     INTEGER,
              captureBufferPacketStatus   INTEGER
          }

          captureBufferControlIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The index of the bufferControlEntry with which
                  this packet is associated."
              ::= { captureBufferEntry 1 }

          captureBufferIndex OBJECT-TYPE
              SYNTAX INTEGER (1..2147483647)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry
                  in the captureBuffer table associated with a
                  particular bufferControlEntry.  This index will
                  start at 1 and increase by one for each new packet
                  added with the same captureBufferControlIndex.

                  Should this value reach 2147483647, the next packet
                  added with the same captureBufferControlIndex shall
                  cause this value to wrap around to 1."
              ::= { captureBufferEntry 2 }

          captureBufferPacketID OBJECT-TYPE
              SYNTAX INTEGER

              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that describes the order of packets
                  that are received on a particular interface.
                  The packetID of a packet captured on an
                  interface is defined to be greater than the
                  packetID's of all packets captured previously on
                  the same interface.  As the captureBufferPacketID
                  object has a maximum positive value of 2^31 - 1,
                  any captureBufferPacketID object shall have the
                  value of the associated packet's packetID mod 2^31."
              ::= { captureBufferEntry 3 }

          captureBufferPacketData OBJECT-TYPE
              SYNTAX OCTET STRING
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The data inside the packet, starting at the
                  beginning of the packet plus any offset specified in
                  the associated bufferControlDownloadOffset,
                  including any link level headers.  The length of the
                  data in this object is the minimum of the length of
                  the captured packet minus the offset, the length of
                  the associated bufferControlCaptureSliceSize minus
                  the offset, and the associated
                  bufferControlDownloadSliceSize.  If this minimum is
                  less than zero, this object shall have a length of
                  zero."
              ::= { captureBufferEntry 4 }

          captureBufferPacketLength OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The actual length (off the wire) of the packet stored
                  in this entry, including FCS octets."
              ::= { captureBufferEntry 5 }

          captureBufferPacketTime OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The number of milliseconds that had passed since
                  this capture buffer was first turned on when this

                  packet was captured."
              ::= { captureBufferEntry 6 }

          captureBufferPacketStatus OBJECT-TYPE
              SYNTAX INTEGER
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "A value which indicates the error status of this
                  packet.

                  The value of this object is defined in the same way as
                  filterPktStatus.  The value is a sum.  This sum
                  initially takes the value zero.  Then, for each
                  error, E, that has been discovered in this packet,
                  2 raised to a value representing E is added to the
                  sum.

                  The errors defined for a packet captured off of an
                  Ethernet interface are as follows:

                      bit #    Error
                          0    Packet is longer than 1518 octets
                          1    Packet is shorter than 64 octets
                          2    Packet experienced a CRC or Alignment
                               error
                          3    First packet in this capture buffer after
                               it was detected that some packets were
                               not processed correctly.
                          4    Packet's order in buffer is only
                               approximate (May only be set for packets
                               sent from the probe)

                  For example, an Ethernet fragment would have a
                  value of 6 (2^1 + 2^2).

                  As this MIB is expanded to new media types, this
                  object will have other media-specific errors defined."
              ::= { captureBufferEntry 7 }

          -- The Event Group

          -- Implementation of the Event group is optional.
          --
          -- The Event group controls the generation and notification
          -- of events from this device.  Each entry in the eventTable
          -- describes the parameters of the event that can be

          -- triggered. Each event entry is fired by an associated
          -- condition located elsewhere in the MIB.  An event entry
          -- may also be associated- with a function elsewhere in the
          -- MIB that will be executed when the event is generated.  For
          -- example, a channel may be turned on or off by the firing
          -- of an event.
          --
          -- Each eventEntry may optionally specify that a log entry
          -- be created on its behalf whenever the event occurs.
          -- Each entry may also specify that notification should
          -- occur by way of SNMP trap messages.  In this case, the
          -- community for the trap message is given in the associated
          -- eventCommunity object.  The enterprise and specific trap
          -- fields of the trap are determined by the condition that
          -- triggered the event.  Two traps are defined: risingAlarm
          -- and fallingAlarm.  If the eventTable is triggered by a
          -- condition specified elsewhere, the enterprise and
          -- specific trap fields must be specified for traps
          -- generated for that condition.

          eventTable OBJECT-TYPE
              SYNTAX SEQUENCE OF EventEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A list of events to be generated."
              ::= { event 1 }

          eventEntry OBJECT-TYPE
              SYNTAX EventEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A set of parameters that describe an event to be
                  generated when certain conditions are met.  As an
                  example, an instance of the eventLastTimeSent object
                  might be named eventLastTimeSent.6"
              INDEX { eventIndex }
              ::= { eventTable 1 }

          EventEntry ::= SEQUENCE {
              eventIndex          INTEGER (1..65535),
              eventDescription    DisplayString (SIZE (0..127)),
              eventType           INTEGER,
              eventCommunity      OCTET STRING (SIZE (0..127)),
              eventLastTimeSent   TimeTicks,
              eventOwner          OwnerString,
              eventStatus         EntryStatus

          }

          eventIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry in the
                  event table.  Each such entry defines one event that
                  is to be generated when the appropriate conditions
                  occur."
              ::= { eventEntry 1 }

          eventDescription OBJECT-TYPE
              SYNTAX DisplayString (SIZE (0..127))
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "A comment describing this event entry."
              ::= { eventEntry 2 }

          eventType OBJECT-TYPE
              SYNTAX INTEGER {
                      none(1),
                      log(2),
                      snmp-trap(3),    -- send an SNMP trap
                      log-and-trap(4)
              }
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "The type of notification that the probe will make
                  about this event.  In the case of log, an entry is
                  made in the log table for each event.  In the case of
                  snmp-trap, an SNMP trap is sent to one or more
                  management stations."
              ::= { eventEntry 3 }

          eventCommunity OBJECT-TYPE
              SYNTAX OCTET STRING (SIZE (0..127))
              ACCESS read-write
              STATUS mandatory
              DESCRIPTION
                  "If an SNMP trap is to be sent, it will be sent to
                  the SNMP community specified by this octet string.
                  In the future this table will be extended to include
                  the party security mechanism.  This object shall be
                  set to a string of length zero if it is intended that

                  that mechanism be used to specify the destination of
                  the trap."
              ::= { eventEntry 4 }

          eventLastTimeSent OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime at the time this event
                  entry last generated an event.  If this entry has
                  not generated any events, this value will be
                  zero."
              ::= { eventEntry 5 }

          eventOwner 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.

                  If this object contains a string starting with
                  'monitor' and has associated entries in the log
                  table, all connected management stations should
                  retrieve those log entries, as they may have
                  significance to all management stations connected to
                  this device"
              ::= { eventEntry 6 }

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

                  If this object is not equal to valid(1), all
                  associated log entries shall be deleted by the
                  agent."
              ::= { eventEntry 7 }

          --
          logTable OBJECT-TYPE
              SYNTAX SEQUENCE OF LogEntry
              ACCESS not-accessible
              STATUS mandatory

              DESCRIPTION
                  "A list of events that have been logged."
              ::= { event 2 }

          logEntry OBJECT-TYPE
              SYNTAX LogEntry
              ACCESS not-accessible
              STATUS mandatory
              DESCRIPTION
                  "A set of data describing an event that has been
                  logged.  For example, an instance of the
                  logDescription object might be named
                  logDescription.6.47"
              INDEX { logEventIndex, logIndex }
              ::= { logTable 1 }

          LogEntry ::= SEQUENCE {
              logEventIndex           INTEGER (1..65535),
              logIndex                INTEGER (1..2147483647),
              logTime                 TimeTicks,
              logDescription          DisplayString (SIZE (0..255))
          }

          logEventIndex OBJECT-TYPE
              SYNTAX INTEGER (1..65535)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The event entry that generated this log
                  entry.  The log identified by a particular
                  value of this index is associated with the same
                  eventEntry as identified by the same value
                  of eventIndex."
              ::= { logEntry 1 }

          logIndex OBJECT-TYPE
              SYNTAX INTEGER (1..2147483647)
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An index that uniquely identifies an entry
                  in the log table amongst those generated by the
                  same eventEntries.  These indexes are
                  assigned beginning with 1 and increase by one
                  with each new log entry.  The association
                  between values of logIndex and logEntries
                  is fixed for the lifetime of each logEntry.
                  The agent may choose to delete the oldest

                  instances of logEntry as required because of
                  lack of memory.  It is an implementation-specific
                  matter as to when this deletion may occur."
              ::= { logEntry 2 }

          logTime OBJECT-TYPE
              SYNTAX TimeTicks
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "The value of sysUpTime when this log entry was
                  created."
              ::= { logEntry 3 }

          logDescription OBJECT-TYPE
              SYNTAX DisplayString (SIZE (0..255))
              ACCESS read-only
              STATUS mandatory
              DESCRIPTION
                  "An implementation dependent description of the
                  event that activated this log entry."
              ::= { logEntry 4 }

          --  These definitions use the TRAP-TYPE macro as
          --  defined in RFC 1215 [10]

          --  Remote Network Monitoring Traps

          risingAlarm TRAP-TYPE
              ENTERPRISE rmon
              VARIABLES { alarmIndex, alarmVariable, alarmSampleType,
                          alarmValue, alarmRisingThreshold }
              DESCRIPTION
                  "The SNMP trap that is generated when an alarm
                  entry crosses its rising threshold and generates
                  an event that is configured for sending SNMP
                  traps."
              ::= 1

          fallingAlarm TRAP-TYPE
              ENTERPRISE rmon
              VARIABLES { alarmIndex, alarmVariable, alarmSampleType,
                          alarmValue, alarmFallingThreshold }
              DESCRIPTION
                  "The SNMP trap that is generated when an alarm
                  entry crosses its falling threshold and generates
                  an event that is configured for sending SNMP
                  traps."

::= 2

END

6. Acknowledgments

This document was produced by the IETF Remote Network Monitoring
Working Group.

7. References

   [1] Cerf, V., "IAB Recommendations for the Development of Internet
       Network Management Standards", RFC 1052, NRI, April 1988.

   [2] Cerf, V., "Report of the Second Ad Hoc Network Management Review
       Group", RFC 1109, NRI, August 1989.

   [3] Rose M., and K. McCloghrie, "Structure and Identification of
       Management Information for TCP/IP-based internets", STD 16, RFC
       1155, Performance Systems International, Hughes LAN Systems, May
       1990.

   [4] McCloghrie K., and M. Rose, Editors, "Management Information Base
       for Network Management of TCP/IP-based internets", STD 17, RFC
       1213, Performance Systems International, March 1991.

   [5] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple
       Network Management Protocol", STD 15, RFC 1157, SNMP Research,
       Performance Systems International, Performance Systems
       International, MIT Laboratory for Computer Science, May 1990.

   [6] McCloghrie, K., and F. Kastenholz, "Evolution of the Interfaces
       Group of MIB-II", RFC 1573, Hughes LAN Systems, FTP Software,
       January 1994.

   [7] Information processing systems - Open Systems Interconnection -
       Specification of Abstract Syntax Notation One (ASN.1),
       International Organization for Standardization.  International
       Standard 8824, (December, 1987).

   [8] Information processing systems - Open Systems Interconnection -
       Specification of Basic Encoding Rules for Abstract Notation One
       (ASN.1), International Organization for Standardization.
       International Standard 8825, (December, 1987).

   [9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions",
       RFC 1212, Performance Systems International, Hughes LAN Systems,
       March 1991.

  [10] Rose, M., Editor, "A Convention for Defining Traps for use with
       the SNMP", RFC 1215, Performance Systems International, March
       1991.

8. Security Considerations

Security issues are not discussed in this memo.

9. Author's Address

   Steven Waldbusser
   Carnegie Mellon University
   5000 Forbes Ave.
   Pittsburgh, PA 15213

   EMail: waldbusser@cmu.edu

10. Appendix: Changes from RFC 1271

   The RMON MIB has not been significantly changed since RFC 1271 was
   issued.

   Two changes were made to object definitions:

  1) A new status bit has been defined for the
     captureBufferPacketStatus object, indicating that the packet
     order within the capture buffer may not be identical to the
     packet order as received off the wire.  This bit may only be used
     for packets transmitted by the probe.  Older NMS applications can
     safely ignore this status bit, which might be used by newer
     agents.

  2) The packetMatch trap has been removed.  This trap was never
     actually 'approved' and was not added to this document along with
     the risingAlarm and fallingAlarm traps. The packetMatch trap
     could not be throttled, which could cause disruption of normal
     network traffic under some circumstances. An NMS should configure
     a risingAlarm threshold on the appropriate channelMatches
     instance if a trap is desired for a packetMatch event. Note that
     logging of packetMatch events is still supported--only trap
     generation for such events has been removed.

   In addition, several clarifications to individual object definitions
   have been added to assist agent and NMS implementors:

     - global definition of "good packets" and "bad packets"

     - more detailed text governing conceptual row creation and
       modification

     - instructions for probes relating to interface changes and
       disruptions

     - clarification of some ethernet counter definitions

     - recommended formula for calculating network utilization

     - clarification of channel and captureBuffer behavior for some
       unusual conditions

     - examples of proper instance naming for each table