Network Working Group                                    J. Cook, Editor
Request for Comments: 1284                           Chipcom Corporation
                                                           December 1991


                     Definitions of Managed Objects
                 for the Ethernet-like Interface Types

Status of this Memo

   This memo is an extension to the SNMP MIB.  This RFC specifies an IAB
   standards track protocol for the Internet community, and requests
   discussion and suggestions for improvements.  Please refer to the
   current edition of the "IAB Official Protocol Standards" for the
   standardization state and status of this protocol.  Distribution of
   this memo is unlimited.

Table of Contents

   1. Abstract...............................................    1
   2. The Network Management Framework.......................    1
   3. Objects ...............................................    2
   3.1 Format of Definitions ................................    2
   4. Overview ..............................................    3
   5. Definitions ...........................................    4
   5.1 The Generic Ethernet-like Group ......................    4
   5.2 The Ethernet-Like Statistics Group ...................    9
   5.3 The Ethernet-like Collision Statistics Group .........   16
   5.4 802.3 Tests ..........................................   17
   5.5 802.3 Hardware Chipsets ..............................   18
   6. Acknowledgements ......................................   19
   7. References ............................................   19
   Security Considerations...................................   21
   Author's Address..........................................   21

1.  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 ethernet-like objects.

2.  The Network Management Framework

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

      RFC 1155 which defines the SMI, the mechanisms used for describing
      and naming objects for the purpose of management.  RFC 1212



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      defines a more concise description mechanism, which is wholly
      consistent with the SMI.

      RFC 1156 which defines MIB-I, the core set of managed objects for
      the Internet suite of protocols.  RFC 1213, defines MIB-II, an
      evolution of MIB-I based on implementation experience and new
      operational requirements.

      RFC 1157 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.

3.  Objects

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1) [7]
   defined in the SMI.  In particular, each object has a name, a syntax,
   and an encoding.  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 language is used for
   this purpose.  However, the SMI [3] purposely restricts the ASN.1
   constructs which may be used.  These restrictions are explicitly made
   for simplicity.

   The encoding of an object type is simply how that object type is
   represented using the object type's syntax.  Implicitly tied to the
   notion of an object type's syntax and encoding is how the object type
   is represented when being transmitted on the network.

   The SMI specifies the use of the basic encoding rules of ASN.1 [8],
   subject to the additional requirements imposed by the SNMP.

3.1.  Format of Definitions

   Section 5 contains contains the specification of all object types
   contained in this MIB module.  The object types are defined using the
   conventions defined in the SMI, as amended by the extensions
   specified in [13].




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4.  Overview

   Instances of these object types represent attributes of an interface
   to an ethernet-like communications medium.  At present, ethernet-like
   media are identified by three values of the ifType object in the
   Internet-standard MIB:

               ethernet-csmacd(6)
               iso88023-csmacd(7)
               starLan(11)

   For these interfaces, the value of the ifSpecific variable in the
   MIB-II [6] has the OBJECT IDENTIFIER value:

               dot3    OBJECT IDENTIFER ::= { transmission 7 }

   The definitions presented here are based on the IEEE 802.3 Layer
   Management Specification [9], as originally interpreted by Frank
   Kastenholz of Interlan in [10].  Implementors of these MIB objects
   should note that the IEEE document explicitly describes (in the form
   of Pascal pseudocode) when, where, and how various MAC attributes are
   measured.  The IEEE document also describes the effects of MAC
   actions that may be invoked by manipulating instances of the MIB
   objects defined here.

   To the extent that some of the attributes defined in [9] are
   represented by previously defined objects in the Internet-standard
   MIB or in the generic interface extensions MIB [11], such attributes
   are not redundantly represented by objects defined in this memo.
   Among the attributes represented by objects defined in other memos
   are the number of octets transmitted or received on a particular
   interface, the number of frames transmitted or received on a
   particular interface, the promiscuous status of an interface, the MAC
   address of an interface, and multicast information associated with an
   interface.

   The relationship between an ethernet-like interface and an interface
   in the context of the Internet-standard MIB is one-to-one.  As such,
   the value of an ifIndex object instance can be directly used to
   identify corresponding instances of the objects defined herein.











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5.  Definitions


    RFC1284-MIB DEFINITIONS ::= BEGIN

    IMPORTS
            Counter, Gauge
                    FROM RFC1155-SMI
            transmission
                    FROM RFC1213-MIB
            OBJECT-TYPE
                    FROM RFC-1212;

    --  This MIB module uses the extended OBJECT-TYPE macro as
    --  defined in [13]


    --  this is the MIB module for ethernet-like objects

    dot3    OBJECT IDENTIFIER ::= { transmission 7 }


    -- the Generic Ethernet-like group

    -- Implementation of this group is mandatory for all systems
    -- that attach to an ethernet-like medium.

    dot3Table OBJECT-TYPE
        SYNTAX  SEQUENCE OF Dot3Entry
        ACCESS  not-accessible
        STATUS  mandatory
        DESCRIPTION
                "Status information and control variables for a
                collection of ethernet-like interfaces attached to
                a particular system."
        ::= { dot3 1 }

    dot3Entry OBJECT-TYPE
        SYNTAX  Dot3Entry
        ACCESS  not-accessible
        STATUS  mandatory
        DESCRIPTION
                "Status information and control variables for a
                particular interface to an ethernet-like medium."
        INDEX   { dot3Index }
        ::= { dot3Table 1 }





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    Dot3Entry ::=
        SEQUENCE {
            dot3Index
                INTEGER,
            dot3InitializeMac
                INTEGER,
            dot3MacSubLayerStatus
                INTEGER,
            dot3MulticastReceiveStatus
                INTEGER,
            dot3TxEnabled
                INTEGER,
            dot3TestTdrValue
                Gauge
       }

    dot3Index OBJECT-TYPE
        SYNTAX  INTEGER
        ACCESS  read-only
        STATUS  mandatory
        DESCRIPTION
                "An index value that uniquely identifies an
                interface to an ethernet-like medium.  The
                interface identified by a particular value of this
                index is the same interface as identified by the
                same value of ifIndex."
        ::= { dot3Entry 1 }

    dot3InitializeMac OBJECT-TYPE
        SYNTAX  INTEGER { initialized(1), uninitialized(2) }
        ACCESS  read-write
        STATUS  mandatory
        DESCRIPTION
                "The initialization status of the MAC and PLS
                (Physical Layer Signalling) subsystems for a
                particular interface. The value initialized(1)
                signifies that the subsystems for a particular
                interface have been previously initialized; the
                value uninitialized(2) signifies that they have
                not been previously initialized.

                Each alteration of an instance of this object to
                either of the values initialized(1) or
                uninitialized(2) is analogous to an invocation of
                the initializeMAC action defined in [9] and has
                the effect of (re-)initializing the MAC and PLS
                subsystems for the associated interface. In
                particular,



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                     all management counters pertaining to the MAC
                     and PLS subsystems for said interface are
                     reset to zero;

                     the receive and transmit layer management
                     state variables (receiveEnabled and
                     transmitEnabled in [9]) are set to enable
                     reception and transmission of frames;

                     the promiscuous receive function is disabled;
                     and

                     multicast reception is disabled."
        ::= { dot3Entry 2 }

    dot3MacSubLayerStatus OBJECT-TYPE
        SYNTAX  INTEGER { enabled(1), disabled(2) }
        ACCESS  read-write
        STATUS  mandatory
        DESCRIPTION
                "The operational status of the MAC sublayer for a
                particular interface.  The value enabled(1)
                signifies that the MAC sublayer for said interface
                is operational for both transmitting and receiving
                frames -- that is, that the value of both the
                receive and transmit layer management state
                variables (receiveEnabled and transmitEnabled in
                [9]) for said interface are true.  The value
                disabled(2) signifies that the MAC sublayer for
                said interface is not operational for either
                transmitting or receiving frames. In particular,
                the value of an instance of this object is
                disabled(2) whenever the value of the
                corresponding instance of the dot3Enabled object
                is false(2).

                Each alteration of an instance of this object to
                the value enabled(1) is analogous to an invocation
                of the enableMACSublayer action defined in [9] and
                has the effect of starting normal transmit and
                receive operations (from the ``idle'' state) on
                the associated interface. In particular, such an
                alteration has the effect of resetting the PLS for
                said interface and of setting the receive and
                transmit layer management state variables
                (receiveEnabled and transmitEnabled in [9]) to be
                true.




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                Each alteration of an instance of this object to
                the value disabled(2) is analogous to an
                invocation of the disableMACSublayer action
                defined in [9] and has the effect of terminating
                transmit and receive operations on the associated
                interface. In particular, such an alteration has
                the effect of setting the receive and transmit
                layer management state variables (receiveEnabled
                and transmitEnabled in [9]) to be false. Any
                transmissions/receptions in progress are completed
                before operation is terminated."
        ::= { dot3Entry 3 }

    dot3MulticastReceiveStatus OBJECT-TYPE
        SYNTAX  INTEGER { enabled(1), disabled(2) }
        ACCESS  read-write
        STATUS  mandatory
        DESCRIPTION
                "The multicast receive status for a particular
                interface.  The value enabled(1) signifies that
                reception of multicast frames by the MAC sublayer
                is enabled on said interface. The value
                disabled(2) signifies that reception of multicast
                frames by the MAC sublayer is not enabled on said
                interface.

                Each alteration of an instance of this object to
                the value enabled(1) is analogous to an invocation
                of the enableMulticastReceive action defined in
                [9] and has the effect of enabling multicast frame
                reception on the associated interface. Actual
                reception of multicast frames is only possible on
                an interface when the values for the associated
                instances of the dot3MulticastReceiveStatus and
                dot3MacSubLayerStatus objects are enabled(1) and
                enabled(1), respectively.

                Each alteration of an instance of this object to
                the value disabled(2) is analogous to an
                invocation of the disableMulticastReceive action
                defined in [9] and has the effect of inhibiting
                multicast frame reception on the associated
                interface."
        ::= { dot3Entry 4 }

    dot3TxEnabled OBJECT-TYPE
        SYNTAX  INTEGER { true(1), false(2)  }
        ACCESS  read-write