IF-MIB DEFINITIONS ::= BEGIN

IMPORTS

    MODULE-IDENTITY, OBJECT-TYPE, Counter32, Gauge32,

    Integer32, TimeTicks,

    Counter64, mib-2, -- added for libsmi use.

    NOTIFICATION-TYPE                        FROM SNMPv2-SMI

    TEXTUAL-CONVENTION, DisplayString,

    PhysAddress, TruthValue, RowStatus,

    AutonomousType, TestAndIncr              FROM SNMPv2-TC

    MODULE-COMPLIANCE, OBJECT-GROUP          FROM SNMPv2-CONF

    IANAifType                               FROM IANAifType-MIB

    -- interfaces                               FROM RFC1213-MIB;

    -- changed to local node definition for libsmi use.

    snmpTraps                                FROM SNMPv2-MIB;

    -- added for libsmi use.

ifMIB MODULE-IDENTITY

    LAST-UPDATED "9311082155Z"

    ORGANIZATION "IETF Interfaces MIB Working Group"

    CONTACT-INFO

               "        Keith McCloghrie

                Postal: Hughes LAN Systems

                        1225 Charleston Road, Mountain View, CA 94043

                Tel:    +1 415 966 7934

                E-Mail: kzm@hls.com

                        Frank Kastenholz

                Postal: FTP Software

                        2 High Street, North Andover, MA 01845

                Tel:    +1 508 685 4000

                E-Mail: kasten@ftp.com"

    DESCRIPTION

            "The MIB module to describe generic objects for

            network interface sub-layers.  This MIB is an updated

            version of MIB-II's ifTable, and incorporates the

            extensions defined in RFC 1229."

    ::= { mib-2 31 }

interfaces   OBJECT IDENTIFIER ::= { mib-2 2 }

ifMIBObjects OBJECT IDENTIFIER ::= { ifMIB 1 }

-- OwnerString has the same semantics as used in RFC 1271

OwnerString ::= TEXTUAL-CONVENTION

    DISPLAY-HINT "255a"

    STATUS       current

    DESCRIPTION

            "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: ASCII form of the manager station's

            transport address, management station name (e.g.,

            domain name), network management personnel'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

            'agent'."

    SYNTAX       OCTET STRING (SIZE(0..255))

-- InterfaceIndex contains the semantics of ifIndex and

-- should be used for any objects defined on other mib

-- modules that need these semantics.

InterfaceIndex ::= TEXTUAL-CONVENTION

    DISPLAY-HINT "d"

    STATUS       current

    DESCRIPTION

            "A unique value, greater than zero, for each interface

            or interface sub-layer in the managed system.  It is

            recommended that values are assigned contiguously

            starting from 1.  The value for each interface sub-

            layer must remain constant at least from one re-

            initialization of the entity's network management

            system to the next re-initialization."

    SYNTAX       Integer32

ifNumber  OBJECT-TYPE

    SYNTAX      Integer32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of network interfaces (regardless of their

            current state) present on this system."

    ::= { interfaces 1 }

-- the Interfaces table

-- The Interfaces table contains information on the entity's

-- interfaces.  Each sub-layer below the internetwork-layer

-- of a network interface is considered to be an interface.

ifTable OBJECT-TYPE

    SYNTAX      SEQUENCE OF IfEntry

    MAX-ACCESS  not-accessible

    STATUS      current

    DESCRIPTION

            "A list of interface entries.  The number of entries

            is given by the value of ifNumber."

    ::= { interfaces 2 }

ifEntry OBJECT-TYPE

    SYNTAX      IfEntry

    MAX-ACCESS  not-accessible

    STATUS      current

    DESCRIPTION

            "An entry containing management information applicable

            to a particular interface."

    INDEX   { ifIndex }

    ::= { ifTable 1 }

IfEntry ::=

    SEQUENCE {

        ifIndex                 InterfaceIndex,

        ifDescr                 DisplayString,

        ifType                  IANAifType,

        ifMtu                   Integer32,

        ifSpeed                 Gauge32,

        ifPhysAddress           PhysAddress,

        ifAdminStatus           INTEGER,

        ifOperStatus            INTEGER,

        ifLastChange            TimeTicks,

        ifInOctets              Counter32,

        ifInUcastPkts           Counter32,

        ifInNUcastPkts          Counter32,  -- deprecated

        ifInDiscards            Counter32,

        ifInErrors              Counter32,

        ifInUnknownProtos       Counter32,

        ifOutOctets             Counter32,

        ifOutUcastPkts          Counter32,

        ifOutNUcastPkts         Counter32,  -- deprecated

        ifOutDiscards           Counter32,

        ifOutErrors             Counter32,

        ifOutQLen               Gauge32,    -- deprecated

        ifSpecific              OBJECT IDENTIFIER -- deprecated

    }

ifIndex OBJECT-TYPE

    SYNTAX      InterfaceIndex

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "A unique value, greater than zero, for each

            interface.  It is recommended that values are assigned

            contiguously starting from 1.  The value for each

            interface sub-layer must remain constant at least from

            one re-initialization of the entity's network

            management system to the next re-initialization."

    ::= { ifEntry 1 }

ifDescr OBJECT-TYPE

    SYNTAX      DisplayString (SIZE (0..255))

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "A textual string containing information about the

            interface.  This string should include the name of the

            manufacturer, the product name and the version of the

            interface hardware/software."

    ::= { ifEntry 2 }

ifType OBJECT-TYPE

    SYNTAX      IANAifType

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The type of interface.  Additional values for ifType

            are assigned by the Internet Assigned Numbers

            Authority (IANA), through updating the syntax of the

            IANAifType textual convention."

    ::= { ifEntry 3 }

ifMtu OBJECT-TYPE

    SYNTAX      Integer32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The size of the largest packet which can be

            sent/received on the interface, specified in octets.

            For interfaces that are used for transmitting network

            datagrams, this is the size of the largest network

            datagram that can be sent on the interface."

    ::= { ifEntry 4 }

ifSpeed OBJECT-TYPE

    SYNTAX      Gauge32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "An estimate of the interface's current bandwidth in

            bits per second.  For interfaces which do not vary in

            bandwidth or for those where no accurate estimation

            can be made, this object should contain the nominal

            bandwidth.  If the bandwidth of the interface is

            greater than the maximum value reportable by this

            object then this object should report its maximum

            value (4,294,967,295) and ifHighSpeed must be used to

            report the interace's speed.  For a sub-layer which

            has no concept of bandwidth, this object should be

            zero."

    ::= { ifEntry 5 }

ifPhysAddress OBJECT-TYPE

    SYNTAX      PhysAddress

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The interface's address at its protocol sub-layer.

            The interface's media-specific MIB must define the bit

            and byte ordering and format of the value contained by

            this object.  For interfaces which do not have such an

            address (e.g., a serial line), this object should

            contain an octet string of zero length."

    ::= { ifEntry 6 }

ifAdminStatus OBJECT-TYPE

    SYNTAX  INTEGER {

                up(1),       -- ready to pass packets

                down(2),

                testing(3)   -- in some test mode

            }

    MAX-ACCESS  read-write

    STATUS      current

    DESCRIPTION

            "The desired state of the interface.  The testing(3)

            state indicates that no operational packets can be

            passed.  When a managed system initializes, all

            interfaces start with ifAdminStatus in the down(2)

            state.  As a result of either explicit management

            action or per configuration information retained by

            the managed system, ifAdminStatus is then changed to

            either the up(1) or testing(3) states (or remains in

            the down(2) state)."

    ::= { ifEntry 7 }

ifOperStatus OBJECT-TYPE

    SYNTAX  INTEGER {

                up(1),       -- ready to pass packets

                down(2),

                testing(3),  -- in some test mode

                unknown(4),  -- status can not be determined

                             -- for some reason.

                dormant(5)

            }

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The current operational state of the interface.  The

            testing(3) state indicates that no operational packets

            can be passed.  If ifAdminStatus is down(2) then

            ifOperStatus should be down(2).  If ifAdminStatus is

            changed to up(1) then ifOperStatus should change to

            up(1) if the interface is ready to transmit and

            receive network traffic; it should change to

            dormant(5) if the interface is waiting for external

            actions (such as a serial line waiting for an

            incomming connection); it should remain in the down(2)

            state if and only if there is a fault that prevents if

            from going to the up(1) state."

    ::= { ifEntry 8 }

ifLastChange OBJECT-TYPE

    SYNTAX      TimeTicks

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The value of sysUpTime at the time the interface

            entered its current operational state.  If the current

            state was entered prior to the last re-initialization

            of the local network management subsystem, then this

            object contains a zero value."

    ::= { ifEntry 9 }

ifInOctets OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of octets received on the interface,

            including framing characters."

    ::= { ifEntry 10 }

ifInUcastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were not addressed to a

            multicast or broadcast address at this sub-layer."

    ::= { ifEntry 11 }

ifInNUcastPkts OBJECT-TYPE

    SYNTAX  Counter32

    MAX-ACCESS  read-only

    STATUS      deprecated

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were addressed to a

            multicast or broadcast address at this sub-layer.

            This object is deprecated in favour of

            ifInMulticastPkts and ifInBroadcastPkts."

    ::= { ifEntry 12 }

ifInDiscards OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of inbound packets which were chosen to be

            discarded even though no errors had been detected to

            prevent their being deliverable to a higher-layer

            protocol.  One possible reason for discarding such a

            packet could be to free up buffer space."

    ::= { ifEntry 13 }

ifInErrors OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "For packet-oriented interfaces, the number of inbound

            packets that contained errors preventing them from

            being deliverable to a higher-layer protocol.  For

            character-oriented or fixed-length interfaces, the

            number of inbound transmission units that contained

            errors preventing them from being deliverable to a

            higher-layer protocol."

    ::= { ifEntry 14 }

ifInUnknownProtos OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "For packet-oriented interfaces, the number of packets

            received via the interface which were discarded

            because of an unknown or unsupported protocol.  For

            character-oriented or fixed-length interfaces which

            support protocol multiplexing the number of

            transmission units received via the interface which

            were discarded because of an unknown or unsupported

            protocol.  For any interface which does not support

            protocol multiplexing, this counter will always be 0."

    ::= { ifEntry 15 }

ifOutOctets OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of octets transmitted out of the

            interface, including framing characters."

    ::= { ifEntry 16 }

ifOutUcastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were not

            addressed to a multicast or broadcast address at this

            sub-layer, including those that were discarded or not

            sent."

    ::= { ifEntry 17 }

ifOutNUcastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      deprecated

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were

            addressed to a multicast or broadcast address at this

            sub-layer, including those that were discarded or not

            sent.

            This object is deprecated in favour of

            ifOutMulticastPkts and ifOutBroadcastPkts."

    ::= { ifEntry 18 }

ifOutDiscards OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of outbound packets which were chosen to

            be discarded even though no errors had been detected

            to prevent their being transmitted.  One possible

            reason for discarding such a packet could be to free

            up buffer space."

    ::= { ifEntry 19 }

ifOutErrors OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "For packet-oriented interfaces, the number of

            outbound packets that could not be transmitted because

            of errors.  For character-oriented or fixed-length

            interfaces, the number of outbound transmission units

            that could not be transmitted because of errors."

    ::= { ifEntry 20 }

ifOutQLen OBJECT-TYPE

    SYNTAX      Gauge32

    MAX-ACCESS  read-only

    STATUS      deprecated

    DESCRIPTION

            "The length of the output packet queue (in packets)."

    ::= { ifEntry 21 }

ifSpecific OBJECT-TYPE

    SYNTAX      OBJECT IDENTIFIER

    MAX-ACCESS  read-only

    STATUS      deprecated

    DESCRIPTION

            "A reference to MIB definitions specific to the

            particular media being used to realize the interface.

            It is recommended that this value point to an instance

            of a MIB object in the media-specific MIB, i.e., that

            this object have the semantics associated with the

            InstancePointer textual convention defined in RFC

            1443.  In fact, it is recommended that the media-

            specific MIB specify what value ifSpecific should/can

            take for values of ifType.  If no MIB definitions

            specific to the particular media are available, the

            value should be set to the OBJECT IDENTIFIER { 0 0 }."

    ::= { ifEntry 22 }

--

--   Extension to the interface table

--

-- This table replaces the ifExtnsTable table.

--

ifXTable        OBJECT-TYPE

    SYNTAX      SEQUENCE OF IfXEntry

    MAX-ACCESS  not-accessible

    STATUS      current

    DESCRIPTION

            "A list of interface entries.  The number of entries

            is given by the value of ifNumber.  This table

            contains additional objects for the interface table."

    ::= { ifMIBObjects 1 }

ifXEntry        OBJECT-TYPE

    SYNTAX      IfXEntry

    MAX-ACCESS  not-accessible

    STATUS      current

    DESCRIPTION

            "An entry containing additional management information

            applicable to a particular interface."

    AUGMENTS    { ifEntry }

    ::= { ifXTable 1 }

IfXEntry ::=

    SEQUENCE {

        ifName                  DisplayString,

        ifInMulticastPkts       Counter32,

        ifInBroadcastPkts       Counter32,

        ifOutMulticastPkts      Counter32,

        ifOutBroadcastPkts      Counter32,

        ifHCInOctets            Counter64,

        ifHCInUcastPkts         Counter64,

        ifHCInMulticastPkts     Counter64,

        ifHCInBroadcastPkts     Counter64,

        ifHCOutOctets           Counter64,

        ifHCOutUcastPkts        Counter64,

        ifHCOutMulticastPkts    Counter64,

        ifHCOutBroadcastPkts    Counter64,

        ifLinkUpDownTrapEnable  INTEGER,

        ifHighSpeed             Gauge32,

        ifPromiscuousMode       TruthValue,

        ifConnectorPresent      TruthValue

    }

ifName OBJECT-TYPE

    SYNTAX      DisplayString

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The textual name of the interface.  The value of this

            object should be the name of the interface as assigned

            by the local device and should be suitable for use in

            commands entered at the device's `console'.  This

            might be a text name, such as `le0' or a simple port

            number, such as `1', depending on the interface naming

            syntax of the device.  If several entries in the

            ifTable together represent a single interface as named

            by the device, then each will have the same value of

            ifName.  If there is no local name, or this object is

            otherwise not applicable, then this object contains a

            0-length string."

    ::= { ifXEntry 1 }

ifInMulticastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were addressed to a

            multicast address at this sub-layer.  For a MAC layer

            protocol, this includes both Group and Functional

            addresses."

    ::= { ifXEntry 2 }

ifInBroadcastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were addressed to a

            broadcast address at this sub-layer."

    ::= { ifXEntry 3 }

ifOutMulticastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were

            addressed to a multicast address at this sub-layer,

            including those that were discarded or not sent.  For

            a MAC layer protocol, this includes both Group and

            Functional addresses."

    ::= { ifXEntry 4 }

ifOutBroadcastPkts OBJECT-TYPE

    SYNTAX      Counter32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were

            addressed to a broadcast address at this sub-layer,

            including those that were discarded or not sent."

    ::= { ifXEntry 5 }

--

-- High Capacity Counter objects.  These objects are all

-- 64 bit versions of the "basic" ifTable counters.  These

-- objects all have the same basic semantics as their 32-bit

-- counterparts, however, their syntax has been extended

-- to 64 bits.

--

ifHCInOctets OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of octets received on the interface,

            including framing characters.  This object is a 64-bit

            version of ifInOctets."

    ::= { ifXEntry 6 }

ifHCInUcastPkts OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were not addressed to a

            multicast or broadcast address at this sub-layer.

            This object is a 64-bit version of ifInUcastPkts."

    ::= { ifXEntry 7 }

ifHCInMulticastPkts OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were addressed to a

            multicast address at this sub-layer.  For a MAC layer

            protocol, this includes both Group and Functional

            addresses.  This object is a 64-bit version of

            ifInMulticastPkts."

    ::= { ifXEntry 8 }

ifHCInBroadcastPkts OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The number of packets, delivered by this sub-layer to

            a higher (sub-)layer, which were addressed to a

            broadcast address at this sub-layer.  This object is a

            64-bit version of ifInBroadcastPkts."

    ::= { ifXEntry 9 }

ifHCOutOctets OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of octets transmitted out of the

            interface, including framing characters.  This object

            is a 64-bit version of ifOutOctets."

    ::= { ifXEntry 10 }

ifHCOutUcastPkts OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were not

            addressed to a multicast or broadcast address at this

            sub-layer, including those that were discarded or not

            sent.  This object is a 64-bit version of

            ifOutUcastPkts."

    ::= { ifXEntry 11 }

ifHCOutMulticastPkts OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were

            addressed to a multicast address at this sub-layer,

            including those that were discarded or not sent.  For

            a MAC layer protocol, this includes both Group and

            Functional addresses.  This object is a 64-bit version

            of ifOutMulticastPkts."

    ::= { ifXEntry 12 }

ifHCOutBroadcastPkts OBJECT-TYPE

    SYNTAX      Counter64

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "The total number of packets that higher-level

            protocols requested be transmitted, and which were

            addressed to a broadcast address at this sub-layer,

            including those that were discarded or not sent.  This

            object is a 64-bit version of ifOutBroadcastPkts."

    ::= { ifXEntry 13 }

ifLinkUpDownTrapEnable  OBJECT-TYPE

    SYNTAX      INTEGER { enabled(1), disabled(2) }

    MAX-ACCESS  read-write

    STATUS      current

    DESCRIPTION

            "Indicates whether linkUp/linkDown traps should be

            generated for this interface.

            By default, this object should have the value

            enabled(1) for interfaces which do not operate on

            'top' of any other interface (as defined in the

            ifStackTable), and disabled(2) otherwise."

    ::= { ifXEntry 14 }

ifHighSpeed OBJECT-TYPE

    SYNTAX      Gauge32

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "An estimate of the interface's current bandwidth in

            units of 1,000,000 bits per second.  If this object

            reports a value of `n' then the speed of the interface

            is somewhere in the range of `n-500,000' to

            `n+499,999'.  For interfaces which do not vary in

            bandwidth or for those where no accurate estimation

            can be made, this object should contain the nominal

            bandwidth.  For a sub-layer which has no concept of

            bandwidth, this object should be zero."

    ::= { ifXEntry 15 }

ifPromiscuousMode  OBJECT-TYPE

    SYNTAX      TruthValue

    MAX-ACCESS  read-write

    STATUS      current

    DESCRIPTION

            "This object has a value of false(2) if this interface

            only accepts packets/frames that are addressed to this

            station.  This object has a value of true(1) when the

            station accepts all packets/frames transmitted on the

            media.  The value true(1) is only legal on certain

            types of media.  If legal, setting this object to a

            value of true(1) may require the interface to be reset

            before becoming effective.

            The value of ifPromiscuousMode does not affect the

            reception of broadcast and multicast packets/frames by

            the interface."

    ::= { ifXEntry 16 }

ifConnectorPresent   OBJECT-TYPE

    SYNTAX      TruthValue

    MAX-ACCESS  read-only

    STATUS      current

    DESCRIPTION

            "This object has the value 'true(1)' if the interface

            sublayer has a physical connector and the value

            'false(2)' otherwise."

    ::= { ifXEntry 17 }

--           The Interface Stack Group

--

-- Implementation of this group is mandatory for all systems

--

ifStackTable  OBJECT-TYPE

     SYNTAX        SEQUENCE OF IfStackEntry

     MAX-ACCESS    not-accessible

     STATUS        current

     DESCRIPTION

            "The table containing information on the relationships

            between the multiple sub-layers of network interfaces.

            In particular, it contains information on which sub-

            layers run 'on top of' which other sub-layers.  Each

            sub-layer corresponds to a conceptual row in the

            ifTable."

     ::= { ifMIBObjects 2 }

ifStackEntry  OBJECT-TYPE

     SYNTAX        IfStackEntry

     MAX-ACCESS    not-accessible

     STATUS        current

     DESCRIPTION

            "Information on a particular relationship between two

            sub-layers, specifying that one sub-layer runs on

            'top' of the other sub-layer.  Each sub-layer

            corresponds to a conceptual row in the ifTable."

     INDEX { ifStackHigherLayer, ifStackLowerLayer }

     ::= { ifStackTable 1 }

IfStackEntry ::=

    SEQUENCE {

        ifStackHigherLayer  Integer32,

        ifStackLowerLayer   Integer32,

        ifStackStatus       RowStatus

     }

ifStackHigherLayer  OBJECT-TYPE

     SYNTAX        Integer32

     MAX-ACCESS    not-accessible

     STATUS        current

     DESCRIPTION

            "The value of ifIndex corresponding to the higher

            sub-layer of the relationship, i.e., the sub-layer

            which runs on 'top' of the sub-layer identified by the

            corresponding instance of ifStackLowerLayer.  If there

            is no higher sub-layer (below the internetwork layer),

            then this object has the value 0."

     ::= { ifStackEntry 1 }

ifStackLowerLayer  OBJECT-TYPE

     SYNTAX        Integer32

     MAX-ACCESS    not-accessible

     STATUS        current

     DESCRIPTION

            "The value of ifIndex corresponding to the lower sub-

            layer of the relationship, i.e., the sub-layer which

            runs 'below' the sub-layer identified by the

            corresponding instance of ifStackHigherLayer.  If

            there is no lower sub-layer, then this object has the

            value 0."

     ::= { ifStackEntry 2 }

ifStackStatus  OBJECT-TYPE

    SYNTAX         RowStatus

    MAX-ACCESS     read-write

    STATUS         current

    DESCRIPTION

            "The status of the relationship between two sub-

            layers.

            Changing the value of this object from 'active' to

            'notInService' or 'destroy' will likely have

            consequences up and down the interface stack.  Thus,

            write access to this object is likely to be

            inappropriate for some types of interfaces, and many

            implementations will choose not to support write-

            access for any type of interface."

    ::= { ifStackEntry 3 }

--

--    The Interface Test Table

--

-- This group of objects is optional.  However, a media-specific

-- MIB may make implementation of this group mandatory.

--

-- This table replaces the ifExtnsTestTable

--

ifTestTable   OBJECT-TYPE

    SYNTAX      SEQUENCE OF IfTestEntry

    MAX-ACCESS  not-accessible

    STATUS      current

    DESCRIPTION

            "This table contains one entry per interface.  It

            defines objects which allow a network manager to

            instruct an agent to test an interface for various

            faults.  Tests for an interface are defined in the

            media-specific MIB for that interface.  After invoking

            a test, the object ifTestResult can be read to

            determine the outcome.  If an agent can not perform

            the test, ifTestResult is set to so indicate.  The

            object ifTestCode can be used to provide further

            test-specific or interface-specific (or even

            enterprise-specific) information concerning the

            outcome of the test.  Only one test can be in progress

            on each interface at any one time.  If one test is in

            progress when another test is invoked, the second test

            is rejected.  Some agents may reject a test when a

            prior test is active on another interface.

            Before starting a test, a manager-station must first

            obtain 'ownership' of the entry in the ifTestTable for

            the interface to be tested.  This is accomplished with

            the ifTestId and ifTestStatus objects as follows:

         try_again:

             get (ifTestId, ifTestStatus)

             while (ifTestStatus != notInUse)

                 /*

                  * Loop while a test is running or some other

                  * manager is configuring a test.