path: root/doc/rfc/rfc3231.txt

Network Working Group                                            D. Levi
Request for Comments: 3231                               Nortel Networks
Obsoletes: 2591                                         J. Schoenwaelder
Category: Standards Track                                TU Braunschweig
                                                            January 2002


                   Definitions of Managed Objects for
                    Scheduling Management Operations

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.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.


Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it describes a set of managed objects that are used to
   schedule management operations periodically or at specified dates and
   times.

   This document obsoletes RFC 2591.

Table of Contents

   1 Introduction .................................................    2
   2 The SNMP Management Framework ................................    2
   3 Overview .....................................................    3
   3.1 Periodic Schedules .........................................    4
   3.2 Calendar Schedules .........................................    4
   3.3 One-shot Schedules .........................................    5
   3.4 Time Transitions ...........................................    5
   3.5 Actions ....................................................    5
   4 Definitions ..................................................    6
   5 Usage Examples ...............................................   20
   5.1 Starting a script to ping devices every 20 minutes .........   20
   5.2 Starting a script at the next Friday the 13th ..............   21
   5.3 Turning an interface off during weekends ...................   22



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   6 Security Considerations ......................................   23
   7 Intellectual Property ........................................   25
   8 Changes from RFC 2591 ........................................   25
   9 Acknowledgments ..............................................   26
   10 References ..................................................   26
   11 Editors' Addresses ..........................................   28
   12 Full Copyright Statement ....................................   29

1.  Introduction

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it describes a set of managed objects that are used to
   schedule management operations periodically or at specified dates and
   times.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.  The SNMP Management Framework

   The SNMP Management Framework presently consists of five major
   components:

   o  An overall architecture, described in RFC 2571 [RFC2571].

   o  Mechanisms for describing and naming objects and events for the
      purpose of management.  The first version of this Structure of
      Management Information (SMI) is called SMIv1 and described in STD
      16, RFC 1155 [RFC1155], STD 16, RFC 1212 [RFC1212] and RFC 1215
      [RFC1215].  The second version, called SMIv2, is described in STD
      58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC
      2580 [RFC2580].

   o  Message protocols for transferring management information.  The
      first version of the SNMP message protocol is called SNMPv1 and
      described in STD 15, RFC 1157 [RFC1157].  A second version of the
      SNMP message protocol, which is not an Internet standards track
      protocol, is called SNMPv2c and described in RFC 1901 [RFC1901]
      and RFC 1906 [RFC1906].  The third version of the message protocol
      is called SNMPv3 and described in RFC 1906 [RFC1906], RFC 2572
      [RFC2572] and RFC 2574 [RFC2574].








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   o  Protocol operations for accessing management information.  The
      first set of protocol operations and associated PDU formats is
      described in STD 15, RFC 1157 [RFC1157].  A second set of protocol
      operations and associated PDU formats is described in RFC 1905
      [RFC1905].

   o  A set of fundamental applications described in RFC 2573 [RFC2573]
      and the view-based access control mechanism described in RFC 2575
      [RFC2575].

   A more detailed introduction to the current SNMP Management Framework
   can be found in RFC 2570 [RFC2570].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the mechanisms defined in the SMI.

   This memo specifies a MIB module that is compliant to the SMIv2.  A
   MIB conforming to the SMIv1 can be produced through the appropriate
   translations.  The resulting translated MIB must be semantically
   equivalent, except where objects or events are omitted because no
   translation is possible (use of Counter64).  Some machine readable
   information in SMIv2 will be converted into textual descriptions in
   SMIv1 during the translation process.  However, this loss of machine
   readable information is not considered to change the semantics of the
   MIB.

3.  Overview

   The MIB defined in this memo provides the scheduling of actions
   periodically or at specified dates and times.  The actions can be
   used to realize on-duty / off-duty schedules or to trigger management
   functions in a distributed management application.

   Schedules can be enabled or disabled by modifying a control object.
   This allows for pre-configured schedules which are activated or
   deactivated by some other management functions.

   The term `scheduler' is used throughout this memo to refer to the
   entity which implements the scheduling MIB and which invokes the
   actions at the specified points in time.










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3.1.  Periodic Schedules

   Periodic schedules are based on fixed time periods between the
   initiation of scheduled actions.  Periodic schedules are defined by
   specifying the number of seconds between two initiations.  The time
   needed to complete the action is usually not known by the scheduler
   and does therefore not influence the next scheduling point.

   Implementations must guarantee that action invocations will not occur
   before their next scheduled time.  However, implementations may be
   forced to delay invocations in the face of local constraints (e.g., a
   heavy load on higher-priority tasks).  An accumulation of such delays
   would result in a drift of the scheduling interval with respect to
   time, and should be avoided.

   Scheduled actions collecting statistical data should retrieve time
   stamps from the data source and not rely on the accuracy of the
   periodic scheduler in order to obtain accurate statistics.

3.2.  Calendar Schedules

   Calendar schedules trigger scheduled actions at specified days of the
   week and days of the month.  Calendar schedules are therefore aware
   of the notion of months, days, weekdays, hours and minutes.

   It is possible to specify multiple values for each calendar item.
   This provides a mechanism for defining complex schedules.  For
   example, a schedule could be defined which triggers an action every
   15 minutes on a given weekday.

   Months, days and weekdays are specified using the objects schedMonth,
   schedDay and schedWeekDay of type BITS.  Setting multiple bits to one
   in these objects causes an OR operation.  For example, setting the
   bits monday(1) and friday(5) in schedWeekDay restricts the schedule
   to Mondays and Fridays.

   The bit fields for schedMonth, schedDay and schedWeekDay are combined
   using an AND operation.  For example, setting the bits june(5) and
   july(6) in schedMonth and combining it with the bits monday(1) and
   friday(5) set in schedWeekDay will result in a schedule which is
   restricted to every Monday and Friday in the months June and July.
   Wildcarding of calendar items is achieved by setting all bits to one.

   It is possible to define calendar schedules that will never trigger
   an action.  For example, one can define a calendar schedule which
   should trigger an action on February 31st.  Schedules like this will
   simply be ignored by the scheduler.




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   Finally, calendar schedules are always expressed in local time.  A
   scalar, schedLocalTime, is provided so that a manager can retrieve
   the notion of local time and the offset to GMT time.

3.3.  One-shot Schedules

   One-shot Schedules are similar to calendar schedules.  The difference
   between a calendar schedule and a one-shot schedule is that a one-
   shot schedule will automatically disable itself once an action has
   been invoked.

3.4.  Time Transitions

   A time transition occurs when the Schedule MIB's notion of time (as
   reported by schedLocalTime) is changed so that time continuity is
   lost.  Time transitions may be caused by daylight savings times or
   administrative changes of the system's notion of time.

   There are two possible situations when a time transition occurs.

   First, time may be set backwards, in which case particular times will
   appear to occur twice.  These are called 'ambiguous times'.  Second,
   time may be set forwards, in which case particular times will not
   occur.  These are called 'nonexistent times'.

   When an action is configured in the Schedule MIB to occur at an
   ambiguous time, the action will be invoked at all occurrences of the
   ambiguous time.  For example, if an action is scheduled to occur at
   2:10 am, and a time transition occurs at 3:00 am which sets the clock
   back to 2:00 am, the action will be invoked twice.

   When an action is configured in the Schedule MIB to occur at a
   nonexistent time, the action will not be invoked at all.  For
   example, if an action is scheduled to occur at 2:10 am, and a time
   transition occurs at 2:00 am which sets the clock to 3:00 am, the
   action will not be invoked.

3.5.  Actions

   Scheduled actions are modeled by SNMP set operations on local MIB
   variables.  Scheduled actions described in this MIB are further
   restricted to objects of type INTEGER.  This restriction does not
   limit the usefulness of the MIB.  Simple schedules such as on-duty /
   off-duty schedules for resources that have a status MIB object (e.g.
   ifAdminStatus) are possible.






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   More complex actions can be realized by triggering a management
   script which is responsible for performing complex state transitions.
   A management script can also be used to perform SNMP set operations
   on remote SNMP engines.

4.  Definitions

   DISMAN-SCHEDULE-MIB DEFINITIONS ::= BEGIN

   IMPORTS
       MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
       Integer32, Unsigned32, Counter32, mib-2, zeroDotZero
           FROM SNMPv2-SMI

       TEXTUAL-CONVENTION,
       DateAndTime, RowStatus, StorageType, VariablePointer
           FROM SNMPv2-TC

       MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
           FROM SNMPv2-CONF

       SnmpAdminString
           FROM SNMP-FRAMEWORK-MIB;

   schedMIB MODULE-IDENTITY
       LAST-UPDATED "200201070000Z"
       ORGANIZATION "IETF Distributed Management Working Group"
       CONTACT-INFO
           "WG EMail:  disman@dorothy.bmc.com
            Subscribe: disman-request@dorothy.bmc.com

            Chair:     Randy Presuhn
                       BMC Software, Inc.
            Postal:    Office 1-3141
                       2141 North First Street
                       San Jose,  California 95131
                       USA
            EMail:     rpresuhn@bmc.com
            Phone:     +1 408 546-1006

            Editor:    David B. Levi
                       Nortel Networks
            Postal:    4401 Great America Parkway
                       Santa Clara, CA 95052-8185
                       USA
            EMail:     dlevi@nortelnetworks.com
            Phone:     +1 865 686 0432




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            Editor:    Juergen Schoenwaelder
                       TU Braunschweig
            Postal:    Bueltenweg 74/75
                       38106 Braunschweig
                       Germany
            EMail:     schoenw@ibr.cs.tu-bs.de
            Phone:     +49 531 391-3283"
       DESCRIPTION
           "This MIB module defines a MIB which provides mechanisms to
            schedule SNMP set operations periodically or at specific
            points in time."
       REVISION    "200201070000Z"
       DESCRIPTION
           "Revised version, published as RFC 3231.

            This revision introduces a new object type called
            schedTriggers.  Created new conformance and compliance
            statements that take care of the new schedTriggers object.

            Several clarifications have been added to remove ambiguities
            that were discovered and reported by implementors."
       REVISION    "199811171800Z"
       DESCRIPTION
           "Initial version, published as RFC 2591."
       ::= { mib-2 63 }

   --
   -- The various groups defined within this MIB definition:
   --

   schedObjects       OBJECT IDENTIFIER ::= { schedMIB 1 }
   schedNotifications OBJECT IDENTIFIER ::= { schedMIB 2 }
   schedConformance   OBJECT IDENTIFIER ::= { schedMIB 3 }

   --
   -- Textual Conventions:
   --

   SnmpPduErrorStatus ::= TEXTUAL-CONVENTION
       STATUS       current
       DESCRIPTION
           "This TC enumerates the SNMPv1 and SNMPv2 PDU error status
            codes as defined in RFC 1157 and RFC 1905.  It also adds a
            pseudo error status code `noResponse' which indicates a
            timeout condition."
       SYNTAX      INTEGER {
                       noResponse(-1),
                       noError(0),



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                       tooBig(1),
                       noSuchName(2),
                       badValue(3),
                       readOnly(4),
                       genErr(5),
                       noAccess(6),
                       wrongType(7),
                       wrongLength(8),
                       wrongEncoding(9),
                       wrongValue(10),
                       noCreation(11),
                       inconsistentValue(12),
                       resourceUnavailable(13),
                       commitFailed(14),
                       undoFailed(15),
                       authorizationError(16),
                       notWritable(17),
                       inconsistentName(18)
                   }

   --
   -- Some scalars which provide information about the local time zone.
   --

   schedLocalTime OBJECT-TYPE
       SYNTAX      DateAndTime (SIZE (11))
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The local time used by the scheduler.  Schedules which
            refer to calendar time will use the local time indicated
            by this object.  An implementation MUST return all 11 bytes
            of the DateAndTime textual-convention so that a manager
            may retrieve the offset from GMT time."
       ::= { schedObjects 1 }

   --
   -- The schedule table which controls the scheduler.
   --

   schedTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF SchedEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "This table defines scheduled actions triggered by
            SNMP set operations."
       ::= { schedObjects 2 }



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   schedEntry OBJECT-TYPE
       SYNTAX      SchedEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "An entry describing a particular scheduled action.

            Unless noted otherwise, writable objects of this row
            can be modified independent of the current value of
            schedRowStatus, schedAdminStatus and schedOperStatus.
            In particular, it is legal to modify schedInterval
            and the objects in the schedCalendarGroup when
            schedRowStatus is active and schedAdminStatus and
            schedOperStatus are both enabled."
       INDEX { schedOwner, schedName }
       ::= { schedTable 1 }

   SchedEntry ::= SEQUENCE {
       schedOwner          SnmpAdminString,
       schedName           SnmpAdminString,
       schedDescr          SnmpAdminString,
       schedInterval       Unsigned32,
       schedWeekDay        BITS,
       schedMonth          BITS,
       schedDay            BITS,
       schedHour           BITS,
       schedMinute         BITS,
       schedContextName    SnmpAdminString,
       schedVariable       VariablePointer,
       schedValue          Integer32,
       schedType           INTEGER,
       schedAdminStatus    INTEGER,
       schedOperStatus     INTEGER,
       schedFailures       Counter32,
       schedLastFailure    SnmpPduErrorStatus,
       schedLastFailed     DateAndTime,
       schedStorageType    StorageType,
       schedRowStatus      RowStatus,
       schedTriggers       Counter32
   }

   schedOwner OBJECT-TYPE
       SYNTAX      SnmpAdminString (SIZE(0..32))
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The owner of this scheduling entry.  The exact semantics of
            this string are subject to the security policy defined by



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            the security administrator."
       ::= { schedEntry 1 }

   schedName OBJECT-TYPE
       SYNTAX      SnmpAdminString (SIZE(1..32))
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The locally-unique, administratively assigned name for this
            scheduling entry.  This object allows a schedOwner to have
            multiple entries in the schedTable."
       ::= { schedEntry 2 }

   schedDescr OBJECT-TYPE
       SYNTAX      SnmpAdminString
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The human readable description of the purpose of this
            scheduling entry."
       DEFVAL      { "" }
       ::= { schedEntry 3 }

   schedInterval OBJECT-TYPE
       SYNTAX      Unsigned32
       UNITS       "seconds"
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The number of seconds between two action invocations of
            a periodic scheduler.  Implementations must guarantee
            that action invocations will not occur before at least
            schedInterval seconds have passed.

            The scheduler must ignore all periodic schedules that
            have a schedInterval value of 0.  A periodic schedule
            with a scheduling interval of 0 seconds will therefore
            never invoke an action.

            Implementations may be forced to delay invocations in the
            face of local constraints.  A scheduled management function
            should therefore not rely on the accuracy provided by the
            scheduler implementation.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { 0 }



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       ::= { schedEntry 4 }

   schedWeekDay OBJECT-TYPE
       SYNTAX      BITS {
                       sunday(0),
                       monday(1),
                       tuesday(2),
                       wednesday(3),
                       thursday(4),
                       friday(5),
                       saturday(6)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The set of weekdays on which the scheduled action should
            take place.  Setting multiple bits will include several
            weekdays in the set of possible weekdays for this schedule.
            Setting all bits will cause the scheduler to ignore the
            weekday.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { {} }
       ::= { schedEntry 5 }

   schedMonth OBJECT-TYPE
       SYNTAX      BITS {
                       january(0),
                       february(1),
                       march(2),
                       april(3),
                       may(4),
                       june(5),
                       july(6),
                       august(7),
                       september(8),
                       october(9),
                       november(10),
                       december(11)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The set of months during which the scheduled action should
            take place.  Setting multiple bits will include several
            months in the set of possible months for this schedule.



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            Setting all bits will cause the scheduler to ignore the
            month.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { {} }
       ::= { schedEntry 6 }

   schedDay OBJECT-TYPE
       SYNTAX      BITS {
                       d1(0),   d2(1),   d3(2),   d4(3),   d5(4),
                       d6(5),   d7(6),   d8(7),   d9(8),   d10(9),
                       d11(10), d12(11), d13(12), d14(13), d15(14),
                       d16(15), d17(16), d18(17), d19(18), d20(19),
                       d21(20), d22(21), d23(22), d24(23), d25(24),
                       d26(25), d27(26), d28(27), d29(28), d30(29),
                       d31(30),
                       r1(31),  r2(32),  r3(33),  r4(34),  r5(35),
                       r6(36),  r7(37),  r8(38),  r9(39),  r10(40),
                       r11(41), r12(42), r13(43), r14(44), r15(45),
                       r16(46), r17(47), r18(48), r19(49), r20(50),
                       r21(51), r22(52), r23(53), r24(54), r25(55),
                       r26(56), r27(57), r28(58), r29(59), r30(60),
                       r31(61)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The set of days in a month on which a scheduled action
            should take place.  There are two sets of bits one can
            use to define the day within a month:

            Enumerations starting with the letter 'd' indicate a
            day in a month relative to the first day of a month.
            The first day of the month can therefore be specified
            by setting the bit d1(0) and d31(30) means the last
            day of a month with 31 days.

            Enumerations starting with the letter 'r' indicate a
            day in a month in reverse order, relative to the last
            day of a month.  The last day in the month can therefore
            be specified by setting the bit r1(31) and r31(61) means
            the first day of a month with 31 days.

            Setting multiple bits will include several days in the set
            of possible days for this schedule.  Setting all bits will
            cause the scheduler to ignore the day within a month.



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            Setting all bits starting with the letter 'd' or the
            letter 'r' will also cause the scheduler to ignore the
            day within a month.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { {} }
       ::= { schedEntry 7 }

   schedHour OBJECT-TYPE
       SYNTAX      BITS {
                       h0(0),   h1(1),   h2(2),   h3(3),   h4(4),
                       h5(5),   h6(6),   h7(7),   h8(8),   h9(9),
                       h10(10), h11(11), h12(12), h13(13), h14(14),
                       h15(15), h16(16), h17(17), h18(18), h19(19),
                       h20(20), h21(21), h22(22), h23(23)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The set of hours within a day during which the scheduled
            action should take place.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { {} }
       ::= { schedEntry 8 }

   schedMinute OBJECT-TYPE
       SYNTAX      BITS {
                       m0(0),   m1(1),   m2(2),   m3(3),   m4(4),
                       m5(5),   m6(6),   m7(7),   m8(8),   m9(9),
                       m10(10), m11(11), m12(12), m13(13), m14(14),
                       m15(15), m16(16), m17(17), m18(18), m19(19),
                       m20(20), m21(21), m22(22), m23(23), m24(24),
                       m25(25), m26(26), m27(27), m28(28), m29(29),
                       m30(30), m31(31), m32(32), m33(33), m34(34),
                       m35(35), m36(36), m37(37), m38(38), m39(39),
                       m40(40), m41(41), m42(42), m43(43), m44(44),
                       m45(45), m46(46), m47(47), m48(48), m49(49),
                       m50(50), m51(51), m52(52), m53(53), m54(54),
                       m55(55), m56(56), m57(57), m58(58), m59(59)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION



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           "The set of minutes within an hour when the scheduled action
            should take place.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { {} }
       ::= { schedEntry 9 }

   schedContextName OBJECT-TYPE
       SYNTAX      SnmpAdminString (SIZE(0..32))
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The context which contains the local MIB variable pointed
            to by schedVariable."
       DEFVAL      { "" }
       ::= { schedEntry 10 }

   schedVariable OBJECT-TYPE
       SYNTAX      VariablePointer
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "An object identifier pointing to a local MIB variable
            which resolves to an ASN.1 primitive type of INTEGER."
       DEFVAL      { zeroDotZero }
       ::= { schedEntry 11 }

   schedValue OBJECT-TYPE
       SYNTAX      Integer32
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The value which is written to the MIB object pointed to by
            schedVariable when the scheduler invokes an action.  The
            implementation shall enforce the use of access control
            rules when performing the set operation on schedVariable.
            This is accomplished by calling the isAccessAllowed abstract
            service interface as defined in RFC 2571.

            Note that an implementation may choose to issue an SNMP Set
            message to the SNMP engine and leave the access control
            decision to the normal message processing procedure."
       DEFVAL      { 0 }
       ::= { schedEntry 12 }

   schedType OBJECT-TYPE



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       SYNTAX      INTEGER {
                       periodic(1),
                       calendar(2),
                       oneshot(3)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The type of this schedule.  The value periodic(1) indicates
            that this entry specifies a periodic schedule.  A periodic
            schedule is defined by the value of schedInterval.  The
            values of schedWeekDay, schedMonth, schedDay, schedHour
            and schedMinute are ignored.

            The value calendar(2) indicates that this entry describes a
            calendar schedule.  A calendar schedule is defined by the
            values of schedWeekDay, schedMonth, schedDay, schedHour and
            schedMinute.  The value of schedInterval is ignored.  A
            calendar schedule will trigger on all local times that
            satisfy the bits set in schedWeekDay, schedMonth, schedDay,
            schedHour and schedMinute.

            The value oneshot(3) indicates that this entry describes a
            one-shot schedule.  A one-shot schedule is similar to a
            calendar schedule with the additional feature that it
            disables itself by changing in the `finished'
            schedOperStatus once the schedule triggers an action.

            Note that implementations which maintain a list of pending
            activations must re-calculate them when this object is
            changed."
       DEFVAL      { periodic }
       ::= { schedEntry 13 }

   schedAdminStatus OBJECT-TYPE
       SYNTAX      INTEGER {
                       enabled(1),
                       disabled(2)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The desired state of the schedule."
       DEFVAL      { disabled }
       ::= { schedEntry 14 }

   schedOperStatus OBJECT-TYPE
       SYNTAX      INTEGER {



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                       enabled(1),
                       disabled(2),
                       finished(3)
                   }
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The current operational state of this schedule.  The state
            enabled(1) indicates this entry is active and that the
            scheduler will invoke actions at appropriate times.  The
            disabled(2) state indicates that this entry is currently
            inactive and ignored by the scheduler.  The finished(3)
            state indicates that the schedule has ended.  Schedules
            in the finished(3) state are ignored by the scheduler.
            A one-shot schedule enters the finished(3) state when it
            deactivates itself.

            Note that the operational state must not be enabled(1)
            when the schedRowStatus is not active."
       ::= { schedEntry 15 }

   schedFailures OBJECT-TYPE
       SYNTAX      Counter32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "This variable counts the number of failures while invoking
            the scheduled action.  This counter at most increments once
            for a triggered action."
       ::= { schedEntry 16 }

   schedLastFailure OBJECT-TYPE
       SYNTAX      SnmpPduErrorStatus
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The most recent error that occurred during the invocation of
            a scheduled action.  The value noError(0) is returned
            if no errors have occurred yet."
       DEFVAL      { noError }
       ::= { schedEntry 17 }

   schedLastFailed OBJECT-TYPE
       SYNTAX      DateAndTime
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The date and time when the most recent failure occurred.



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            The value '0000000000000000'H is returned if no failure
            occurred since the last re-initialization of the scheduler."
       DEFVAL      { '0000000000000000'H }
       ::= { schedEntry 18 }

   schedStorageType OBJECT-TYPE
       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "This object defines whether this scheduled action is kept
            in volatile storage and lost upon reboot or if this row is
            backed up by non-volatile or permanent storage.

            Conceptual rows having the value `permanent' must allow
            write access to the columnar objects schedDescr,
            schedInterval, schedContextName, schedVariable, schedValue,
            and schedAdminStatus.  If an implementation supports the
            schedCalendarGroup, write access must be also allowed to
            the columnar objects schedWeekDay, schedMonth, schedDay,
            schedHour, schedMinute."
       DEFVAL      { volatile }
       ::= { schedEntry 19 }

   schedRowStatus OBJECT-TYPE
       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The status of this scheduled action.  A control that allows
            entries to be added and removed from this table.

            Note that the operational state must change to enabled
            when the administrative state is enabled and the row
            status changes to active(1).

            Attempts to destroy(6) a row or to set a row
            notInService(2) while the operational state is enabled
            result in inconsistentValue errors.

            The value of this object has no effect on whether other
            objects in this conceptual row can be modified."
       ::= { schedEntry 20 }

   schedTriggers OBJECT-TYPE
       SYNTAX      Counter32
       MAX-ACCESS  read-only
       STATUS      current



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       DESCRIPTION
           "This variable counts the number of attempts (either
            successful or failed) to invoke the scheduled action."
       ::= { schedEntry 21 }

   --
   -- Notifications that are emitted to indicate failures.  The
   -- definition of schedTraps makes notification registrations
   -- reversible (see STD 58, RFC 2578).
   --

   schedTraps OBJECT IDENTIFIER ::= { schedNotifications 0 }

   schedActionFailure NOTIFICATION-TYPE
       OBJECTS     { schedLastFailure, schedLastFailed }
       STATUS      current
       DESCRIPTION
           "This notification is generated whenever the invocation of a
            scheduled action fails."
       ::= { schedTraps 1 }

   -- conformance information

   schedCompliances OBJECT IDENTIFIER ::= { schedConformance 1 }
   schedGroups      OBJECT IDENTIFIER ::= { schedConformance 2 }

   -- compliance statements

   schedCompliance2 MODULE-COMPLIANCE
       STATUS      current
       DESCRIPTION
           "The compliance statement for SNMP entities which implement
            the scheduling MIB."
       MODULE      -- this module
       MANDATORY-GROUPS {
              schedGroup2, schedNotificationsGroup
       }
       GROUP  schedCalendarGroup
       DESCRIPTION
           "The schedCalendarGroup is mandatory only for those
            implementations that support calendar based schedules."
       OBJECT schedType
       DESCRIPTION
           "The values calendar(2) or oneshot(3) are not valid for
            implementations that do not implement the
            schedCalendarGroup.  Such an implementation must return
            inconsistentValue error responses for attempts to set
            schedAdminStatus to calendar(2) or oneshot(3)."



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       ::= { schedCompliances 2 }

   schedGroup2 OBJECT-GROUP
       OBJECTS {
           schedDescr, schedInterval, schedContextName,
           schedVariable, schedValue, schedType,
           schedAdminStatus, schedOperStatus, schedFailures,
           schedLastFailure, schedLastFailed, schedStorageType,
           schedRowStatus, schedTriggers
       }
       STATUS      current
       DESCRIPTION
           "A collection of objects providing scheduling capabilities."
       ::= { schedGroups 4 }

   schedCalendarGroup OBJECT-GROUP
       OBJECTS {
           schedLocalTime, schedWeekDay, schedMonth,
           schedDay, schedHour, schedMinute
       }
       STATUS      current
       DESCRIPTION
           "A collection of objects providing calendar based schedules."
       ::= { schedGroups 2 }

   schedNotificationsGroup NOTIFICATION-GROUP
       NOTIFICATIONS {
           schedActionFailure
       }
       STATUS      current
       DESCRIPTION
           "The notifications emitted by the scheduler."
       ::= { schedGroups 3 }

   --
   -- Deprecated compliance and conformance group definitions
   -- from RFC 2591.
   --

   schedCompliance MODULE-COMPLIANCE
       STATUS      deprecated
       DESCRIPTION
           "The compliance statement for SNMP entities which implement
            the scheduling MIB."
       MODULE      -- this module
       MANDATORY-GROUPS {
              schedGroup, schedNotificationsGroup
       }



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       GROUP  schedCalendarGroup
       DESCRIPTION
           "The schedCalendarGroup is mandatory only for those
            implementations that support calendar based schedules."
       OBJECT schedType
       DESCRIPTION
           "The values calendar(2) or oneshot(3) are not valid for
            implementations that do not implement the
            schedCalendarGroup.  Such an implementation must return
            inconsistentValue error responses for attempts to set
            schedAdminStatus to calendar(2) or oneshot(3)."
       ::= { schedCompliances 1 }

   schedGroup OBJECT-GROUP
       OBJECTS {
           schedDescr, schedInterval, schedContextName,
           schedVariable, schedValue, schedType,
           schedAdminStatus, schedOperStatus, schedFailures,
           schedLastFailure, schedLastFailed, schedStorageType,
           schedRowStatus
       }
       STATUS      deprecated
       DESCRIPTION
           "A collection of objects providing scheduling capabilities."
       ::= { schedGroups 1 }

   END

5.  Usage Examples

   This section presents some examples how the scheduling MIB can be
   used to schedule scripts with the Script MIB [RFC3165] or to realize
   on-duty/off-duty schedules by modifying status objects of other MIB
   modules.

5.1.  Starting a script to ping devices every 20 minutes

   It is assumed that the schedule entry is owned by schedOwner = "joe"
   and its name is schedName = "ping".  The instance identifier for the
   scheduling entry is therefore 3.106.111.101.4.112.105.110.103.

   It is further assumed that the smLaunchTable entry is owned by
   smLaunchOwner = "joe" and its name is smLaunchName = "ping-devs".
   The complete object identifier for the smLaunchStart object is
   therefore
   smLaunchStart.3.106.111.101.9.112.105.110.103.45.100.101.118.115.
   The script lives in the context identified by the string "engine1".




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   The configuration of the scheduler entry which launches the script
   every 20 minutes would look as follows:

      schedInterval.3.106.111.101.4.112.105.110.103 = 1200

      schedValue.3.106.111.101.4.112.105.110.103 = 0
      schedContextName.3.106.111.101.4.112.105.110.103 = "engine1"
      schedVariable.3.106.111.101.4.112.105.110.103 =
        smLaunchStart.3.106.111.101.9.112.105.110.103.45.100.101.118.115

      schedType.3.106.111.101.4.112.105.110.103 = periodic(1)
      schedAdminStatus.3.106.111.101.4.112.105.110.103 = enabled(1)
      schedStorageType.3.106.111.101.4.112.105.110.103 = nonVolatile(3)
      schedRowStatus.3.106.111.101.4.112.105.110.103 = active(1)

   All the remaining columns in the schedTable represent status
   information and are not shown here.

5.2.  Starting a script at the next Friday the 13th

   It is assumed that the schedule entry is owned by schedOwner = "joe"
   and its name is schedName = "13th".  The instance identifier for the
   scheduling entry is therefore 3.106.111.101.4.49.51.116.104.

   It is further assumed that the smLaunchTable entry is owned by
   smLaunchOwner = "joe" and its name is smLaunchName = "ghost".  The
   complete object identifier for the smLaunchStart object is therefore
   smLaunchStart.3.106.111.101.5.103.104.111.115.116.  The script lives
   in the context identified by the string "engine1".

   The configuration of the scheduler entry which launches the script on
   the next Friday 13th at midnight would look as follows:

      schedWeekDay.3.106.111.101.4.49.51.116.104 = { friday }
      schedMonth.3.106.111.101.4.49.51.116.104 = {
            january, february, march, april, may, june,
            july, august, september, october, november, december
      }
      schedDay.3.106.111.101.4.49.51.116.104 = { d13 }
      schedHour.3.106.111.101.4.49.51.116.104 = { h0 }
      schedMinute.3.106.111.101.4.49.51.116.104 = { m0 }

      schedValue.3.106.111.101.4.49.51.116.104 = 0
      schedContextName.3.106.111.101.4.49.51.116.104 = "engine1"
      schedVariable.3.106.111.101.4.49.51.116.104 =
        smLaunchStart.3.106.111.101.5.103.104.111.115.116





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      schedType.3.106.111.101.4.49.51.116.104 = oneshot(3)
      schedAdminStatus.3.106.111.101.4.49.51.116.104 = enabled(2)
      schedStorageType.3.106.111.101.4.49.51.116.104 = nonVolatile(3)
      schedRowStatus.3.106.111.101.4.49.51.116.104 = active(1)

   All the remaining columns in the schedTable represent status
   information and are not shown here.

5.3.  Turning an interface off during weekends

   This example assumes that a network interface should be taken down
   during weekends.  The interface table (ifTable) of the IF-MIB
   [RFC2863] is assumed to exist in the context identified by an empty
   string and the index of the interface is ifIndex = 6.

   The scheduling entry which brings the interface down on every Friday
   evening at 20:30 (8:30 pm) is owned by schedOwner = "bob" and its
   name is schedName = "if-off".  The instance identifier for the
   scheduling entry is therefore 3.98.111.98.6.105.102.45.111.102.102.

      schedWeekDay.3.98.111.98.6.105.102.45.111.102.102 = { friday }
      schedMonth.3.98.111.98.6.105.102.45.111.102.102 = {
            january, february, march, april, may, june,
            july, august, september, october, november, december
      }
      schedDay.3.98.111.98.6.105.102.45.111.102.102 = {
            d1, d2, d3, d4, d5, d6, d7, d8, d9, d10,
            d11, d12, d13, d14, d15, d16, d17, d18, d19, d20,
            d21, d22, d23, d24, d25, d26, d27, d28, d29, d30, d31
      }
      schedHour.3.98.111.98.6.105.102.45.111.102.102 = { h20 }
      schedMinute.3.98.111.98.6.105.102.45.111.102.102 = { m30 }
      schedValue.3.98.111.98.6.105.102.45.111.102.102 = down(2)
      schedContextName.3.98.111.98.6.105.102.45.111.102.102 = ""
      schedVariable.3.98.111.98.6.105.102.45.111.102.102 =
        ifAdminStatus.6

      schedType.3.98.111.98.6.105.102.45.111.102.102 = calendar(2)
      schedAdminStatus.3.98.111.98.6.105.102.45.111.102.102 = enabled(1)
      schedStorageType.3.98.111.98.6.105.102.45.111.102.102 =
        nonVolatile(3)
      schedRowStatus.3.98.111.98.6.105.102.45.111.102.102 = active(1)

   The scheduling entry which brings the interface up on every Monday
   morning at 5:30 is owned by schedOwner = "bob" and its name is
   schedName = "if-on".  The instance identifier for the scheduling
   entry is therefore 3.98.111.98.5.105.102.45.111.110.




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   The entry in the schedTable which brings the interface up again on
   every Monday morning at 5:30 looks as follows:

      schedWeekDay.3.98.111.98.5.105.102.45.111.110 = { monday }
      schedMonth.3.98.111.98.5.105.102.45.111.110 = {
            january, february, march, april, may, june,
            july, august, september, october, november, december
      }
      schedDay.3.98.111.98.5.105.102.45.111.110 = {
            d1, d2, d3, d4, d5, d6, d7, d8, d9, d10,
            d11, d12, d13, d14, d15, d16, d17, d18, d19, d20,
            d21, d22, d23, d24, d25, d26, d27, d28, d29, d30, d31
      }
      schedHour.3.98.111.98.5.105.102.45.111.110 = { h5 }
      schedMinute.3.98.111.98.5.105.102.45.111.110 = { m30 }

      schedValue.3.98.111.98.5.105.102.45.111.110 = up(1)
      schedContextName.3.98.111.98.5.105.102.45.111.110 = ""
      schedVariable.3.98.111.98.5.105.102.45.111.110 = ifAdminStatus.6

      schedType.3.98.111.98.5.105.102.45.111.110 = calendar(2)
      schedAdminStatus.3.98.111.98.5.105.102.45.111.110 = enabled(1)
      schedStorageType.3.98.111.98.5.105.102.45.111.110 = nonVolatile(3)
      schedRowStatus.3.98.111.98.5.105.102.45.111.110 = active(1)

   A similar configuration could be used to control other schedules.
   For example, one could change the "if-on" and "if-off" schedules to
   enable and disable the periodic scheduler defined in the first
   example.

6.  Security Considerations

   There are a number of management objects defined in this MIB that
   have a MAX-ACCESS clause of read-write and/or read-create.  Such
   objects may be considered sensitive or vulnerable in some network
   environments.  The support for SET operations in a non-secure
   environment without proper protection can have a negative effect on
   network operations.

   SNMPv1 by itself is not a secure environment.  Even if the network
   itself is secure (for example by using IPSec), even then, there is no
   control as to who on the secure network is allowed to access and
   GET/SET (read/change/create/delete) the objects in this MIB.

   It is recommended that the implementers consider the security
   features as provided by the SNMPv3 framework.  Specifically, the use
   of the User-based Security Model RFC 2574 [RFC2574] and the View-
   based Access Control Model RFC 2575 [RFC2575] is recommended.



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   It is then a customer/user responsibility to ensure that the SNMP
   entity giving access to an instance of this MIB, is properly
   configured to give access to the objects only to those principals
   (users) that have legitimate rights to indeed GET or SET
   (change/create/delete) them.

   Scheduled SNMP set operations must use the security credentials that
   were present when the corresponding row in the scheduling entry was
   created.  An implementation must therefore record and maintain the
   credentials for every scheduling entry.

   An implementation must ensure that access control rules are applied
   when doing the set operation.  This is accomplished by calling the
   isAccessAllowed abstract service interface defined in RFC 2571
   [RFC2571]:

      statusInformation =          -- success or errorIndication
        isAccessAllowed(
        IN   securityModel         -- Security Model in use
        IN   securityName          -- principal who wants to access
        IN   securityLevel         -- Level of Security
        IN   viewType              -- read, write, or notify view
        IN   contextName           -- context containing variableName
        IN   variableName          -- OID for the managed object
             )

   The securityModel, securityName and securityLevel parameters are set
   to the values that were recorded when the scheduling entry was
   created.  The viewType parameter must select the write view and the
   contextName and variableName parameters are taken from the
   schedContextName and schedVariableName values of the scheduling
   entry.

   This MIB limits scheduled actions to objects in the local MIB.  This
   avoids security problems with the delegation of access rights.
   However, it might be possible for a user of this MIB to own some
   schedules that might trigger far in the future.  This can cause
   security risks if the security administrator did not properly update
   the access control lists when a user is withdrawn from an SNMP
   engine.  Therefore, entries in the schedTable SHOULD be cleaned up
   whenever a user is removed from an SNMP engine.

   To facilitate the provisioning of access control by a security
   administrator using the View-Based Access Control Model (VACM)
   defined in RFC 2575 [RFC2575] for tables in which multiple users may
   need to independently create or modify entries, the initial index is
   used as an "owner index".  Such an initial index has a syntax of




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   SnmpAdminString, and can thus be trivially mapped to a securityName
   or groupName as defined in VACM, in accordance with a security
   policy.

   All entries in related tables belonging to a particular user will
   have the same value for this initial index.  For a given user's
   entries in a particular table, the object identifiers for the
   information in these entries will have the same subidentifiers
   (except for the "column" subidentifier) up to the end of the encoded
   owner index.  To configure VACM to permit access to this portion of
   the table, one would create vacmViewTreeFamilyTable entries with the
   value of vacmViewTreeFamilySubtree including the owner index portion,
   and vacmViewTreeFamilyMask "wildcarding" the column subidentifier.
   More elaborate configurations are possible.

7.  Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP 11, RFC 2028.
   Copies of claims of rights made available for publication and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementors or users of this
   specification can be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive
   Director.

8.  Changes from RFC 2591

   The following list documents major changes from the previous version
   of this document, published as RFC 2591:

   -  Updated the SNMP Management Framework boilerplate and the
      references.

   -  Added revision clauses to the module identity macro.

   -  Clarified the behavior during time transitions.



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   -  Clarified that schedInterval and schedCalendarGroup objects can be
      modified regardless of the current value of schedRowStatus,
      schedAdminStatus and schedOperStatus.

   -  Added some additional boilerplate text to the security
      considerations section.

   -  Clarified that implementations must re-calculate any pending
      action invocations when scheduling parameters are modified.

   -  Clarified that schedOperStatus must not be enabled while the
      schedRowStatus is not active.

   -  Clarified that schedRowStatus can not be changed as long as the
      schedOperStatus is enabled.

   -  Clarified that implementations can delegate the isAccessAllowed
      check by sending themself an SNMP Set message.

   -  Added the schedTriggers object which counts the total number of
      triggers.

   -  Added DEFVALs for schedContextName, schedVariable, and schedValue
      and updated the schedRowStatus description.

   -  Deprecated schedCompliance, schedGroup and created
      schedCompliance2 and schedGroup2 that take care of the new
      schedTriggers object.

9.  Acknowledgments

   This document was produced by the IETF Distributed Management
   (DISMAN) working group.

10.  References

   [RFC2571]  Harrington, D., Presuhn, R. and B. Wijnen, "An
              Architecture for Describing SNMP Management Frameworks",
              RFC 2571, April 1999.

   [RFC1155]  Rose, M. and K. McCloghrie, "Structure and Identification
              of Management Information for TCP/IP-based Internets", STD
              16, RFC 1155, May 1990.

   [RFC1212]  Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD
              16, RFC 1212, March 1991.





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   [RFC1215]  Rose, M., "A Convention for Defining Traps for use with
              the SNMP", RFC 1215, March 1991.

   [RFC2578]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
              Rose, M. and S. Waldbusser, "Structure of Management
              Information Version 2 (SMIv2)", STD 58, RFC 2578, April
              1999.

   [RFC2579]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
              Rose, M. and S. Waldbusser, "Textual Conventions for
              SMIv2", STD 58, RFC 2579, April 1999.

   [RFC2580]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
              Rose, M. and S. Waldbusser, "Conformance Statements for
              SMIv2", STD 58, RFC 2580, April 1999.

   [RFC1157]  Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
              Network Management Protocol", STD 15, RFC 1157, May 1990.

   [RFC1901]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
              "Introduction to Community-based SNMPv2", RFC 1901,
              January 1996.

   [RFC1906]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
              "Transport Mappings for Version 2 of the Simple Network
              Management Protocol (SNMPv2)", RFC 1906, January 1996.

   [RFC2572]  Case, J., Harrington D., Presuhn R. and B. Wijnen,
              "Message Processing and Dispatching for the Simple Network
              Management Protocol (SNMP)", RFC 2572, April 1999.

   [RFC2574]  Blumenthal, U. and B. Wijnen, "User-based Security Model
              (USM) for version 3 of the Simple Network Management
              Protocol (SNMPv3)", RFC 2574, April 1999.

   [RFC1905]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
              "Protocol Operations for Version 2 of the Simple Network
              Management Protocol (SNMPv2)", RFC 1905, January 1996.

   [RFC2573]  Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications",
              RFC 2573, April 1999.

   [RFC2575]  Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based
              Access Control Model (VACM) for the Simple Network
              Management Protocol (SNMP)", RFC 2575, April 1999.






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   [RFC2570]  Case, J., Mundy, R., Partain, D. and B. Stewart,
              "Introduction to Version 3 of the Internet-standard
              Network Management Framework", RFC 2570, April 1999.

   [RFC2028]  Hovey, R. and S. Bradner, "The Organizations Involved in
              the IETF Standards Process", BCP 11, RFC 2028, October
              1996.

   [RFC3165]  Levi, D. and J. Schoenwaelder, "Definitions of Managed
              Objects for the Delegation of Management Scripts", RFC
              3165, August 2001.

   [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
              MIB", RFC 2863, June 2000.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

11.  Editors' Addresses

   David B. Levi
   Nortel Networks
   4401 Great America Parkway
   Santa Clara, CA 95052-8185
   USA

   Phone: +1 865 686 0432
   EMail: dlevi@nortelnetworks.com


   Juergen Schoenwaelder
   TU Braunschweig
   Bueltenweg 74/75
   38106 Braunschweig
   Germany

   Phone: +49 531 391-3283
   EMail: schoenw@ibr.cs.tu-bs.de













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RFC 3231                      Schedule MIB                  January 2002


12.  Full Copyright Statement

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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