Network Working Group D. Levi

Network Working Group D. Levi
Request for Comments: 2591 Nortel Networks
Category: Standards Track J. Schoenwaelder
TU Braunschweig
May 1999

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 (1999). 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.

Table of Contents

1. Introduction ....................................................2
2. The SNMP Management Framework....................................2
3. Overview ........................................................3
3.1 Periodic Schedules .............................................3
3.2 Calendar Schedules .............................................4
3.3 One-shot Schedules .............................................4
3.4 Time Transitions ...............................................4
3.5 Actions ........................................................5
4. Definitions .....................................................5
5. Usage Examples .................................................18
5.1 Starting a script to ping devices every 20 minutes ............18
5.2 Starting a script at the next Friday the 13th .................18
5.3 Turning an interface off during weekends ......................19
6. Security Considerations ........................................21
7. Intellectual Property ..........................................22
8. Acknowledgments ................................................22

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RFC 2591 Scheduling MIB May 1999

9. References .....................................................22
10. Editors' Addresses ............................................24
11. Full Copyright Statement ......................................25

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 [19].

2. The SNMP Management Framework

The SNMP Management Framework presently consists of five major
components:

o An overall architecture, described in RFC 2271 [1].

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 [2], STD 16, RFC 1212 [3] and RFC 1215 [4]. The
second version, called SMIv2, is described in STD 58, RFC 2578
[5], RFC 2579 [6] and RFC 2580 [7].

o Message protocols for transferring management information. The
first version of the SNMP message protocol is called SNMPv1 and
described in RFC 1157 [8]. A second version of the SNMP message
protocol, which is not an Internet standards track protocol, is
called SNMPv2c and described in RFC 1901 [9] and RFC 1906 [10].
The third version of the message protocol is called SNMPv3 and
described in RFC 1906 [10], RFC 2272 [11] and RFC 2274 [12].

o Protocol operations for accessing management information. The
first set of protocol operations and associated PDU formats is
described in STD 15, RFC 1157 [8]. A second set of protocol
operations and associated PDU formats is described in RFC 1905
[13].

o A set of fundamental applications described in RFC 2273 [14] and
the view-based access control mechanism described in RFC 2275
[15].

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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 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 pre-configured schedules which are activated or de-
activated 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.

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.

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RFC 2591 Scheduling MIB May 1999

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.

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

When a system's notion of time is changed for some reason,
implementations of the Schedule MIB must schedule actions
differently. One example of a change to a system's notion of time is
when a daylight savings time transition occurs.

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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 within the same day. These are called
'ambiguous times'. Second, time may be set forwards, in which case
particular times will appear to not occur within a day. This are
called 'nonexistent times'.

When an action is configured in the Schedule MIB to occur at an
ambiguous time during a time transition, the action SHALL only be
invoked at the first occurence of the ambiguous time. For example,
if an action is scheduled to occur at 2:00 am, and a time transition
occurs at 3:00 am which sets the clock back to 2:00 am, the action
SHALL only be invoked at the first occurence of 2:00 am.

When an action is configured in the Schedule MIB to occur at a
nonexistent time, the action SHOULD be invoked immediately upon a
time transition. If multiple actions are invoked in this way, they
SHALL be invoked in the order in which they normally would be invoked
had the time transition not occured. For example, if an action (a) is
scheduled at 2:05 am and another action (b) at 2:10 am, then both
actions SHOULD be invoked at 3:00 am in the order (a),(b) if the time
jumps forward from 2:00 am to 3:00 am.

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.

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
FROM SNMPv2-SMI

TEXTUAL-CONVENTION,
DateAndTime, RowStatus, StorageType, VariablePointer

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FROM SNMPv2-TC

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

SnmpAdminString
FROM SNMP-FRAMEWORK-MIB;

schedMIB MODULE-IDENTITY
LAST-UPDATED "9811171800Z"
ORGANIZATION "IETF Distributed Management Working Group"
CONTACT-INFO
"David B. Levi
Nortel Networks
4401 Great America Parkway
Santa Clara, CA 95052-8185
U.S.A.
Tel: +1 423 686 0432
E-mail: [email protected]

Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Tel: +49 531 391-3283
E-mail: [email protected]"
DESCRIPTION
"This MIB module defines a MIB which provides mechanisms
to schedule SNMP set operations periodically or at
specific points in time."
::= { 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

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"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),
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.
--

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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 }

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

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 { ''H }
::= { 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."
DEFVAL { 0 }
::= { schedEntry 4 }

schedWeekDay OBJECT-TYPE
SYNTAX BITS {

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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."
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.
Setting all bits will cause the scheduler to ignore the
month."
DEFVAL { {} }
::= { schedEntry 6 }

schedDay OBJECT-TYPE
SYNTAX BITS {
d1(0), d2(1), d3(2), d4(3), d5(4),

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

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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."
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
"The set of minutes within an hour when the scheduled action
should take place."
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."
::= { schedEntry 10 }

schedVariable OBJECT-TYPE
SYNTAX VariablePointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An object identifier pointing to a local MIB variable

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which resolves to an ASN.1 primitive type of INTEGER."
::= { 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 2271."
::= { schedEntry 12 }

schedType OBJECT-TYPE
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.

Changing a schedule's type is equivalent to deleting the
old-type schedule and creating a new-type one."
DEFVAL { periodic }

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::= { 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 {
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."
::= { 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."
::= { schedEntry 16 }

schedLastFailure OBJECT-TYPE
SYNTAX SnmpPduErrorStatus
MAX-ACCESS read-only
STATUS current
DESCRIPTION

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"The most recent error that occured 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 occured. The
value '0000000000000000'H is returned if no failure occured
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.

The miminum number of objects that need to be set during
row creation before a row can be set to `active' are
schedContextName, schedVariable and schedValue."
::= { schedEntry 20 }

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--
-- 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

schedCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for SNMP entities which implement
the scheduling MIB."
MODULE -- this module
MANDATORY-GROUPS {
schedGroup, 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)."
::= { schedCompliances 1 }

schedGroup OBJECT-GROUP
OBJECTS {
schedDescr,

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RFC 2591 Scheduling MIB May 1999

schedInterval,
schedContextName,
schedVariable,
schedValue,
schedType,
schedAdminStatus,
schedOperStatus,
schedFailures,
schedLastFailure,
schedLastFailed,
schedStorageType,
schedRowStatus
}
STATUS current
DESCRIPTION
"A collection of objects providing scheduling capabilities."
::= { schedGroups 1 }

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 }

END

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5. Usage Examples

This section presents some examples how the scheduling MIB can be
used to schedule scripts with the Script MIB [17] 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".

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".

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RFC 2591 Scheduling MIB May 1999

The configuration of the scheduler entry which launches the script on
every 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

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 [18] 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 }

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RFC 2591 Scheduling MIB May 1999

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.

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.

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RFC 2591 Scheduling MIB May 1999

6. Security Considerations

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 2271 [1]:

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 2275 [15] 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
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

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RFC 2591 Scheduling MIB May 1999

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. 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. Acknowledgments

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

9. References

[1] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
Describing SNMP Management Frameworks", RFC 2271, January 1998.

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

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

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RFC 2591 Scheduling MIB May 1999

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

[5] 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.

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

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

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

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

[10] 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.

[11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
Processing and Dispatching for the Simple Network Management
Protocol (SNMP)", RFC 2272, January 1998.

[12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
for version 3 of the Simple Network Management Protocol
(SNMPv3)", RFC 2274, January 1998.

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

[14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
2273, January 1998

[15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
Control Model (VACM) for the Simple Network Management Protocol
(SNMP)", RFC 2275, January 1998.

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

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RFC 2591 Scheduling MIB May 1999

[17] Levi, D. and J. Schoenwaelder, "Definitions of Managed Objects
for the Delegation of Management Scripts", RFC 2592, May 1999.

[18] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB
using SMIv2", RFC 2233, November 1997.

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

10. Editors' Addresses

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

Phone: +1 423 686 0432
EMail: [email protected]

Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany

Phone: +49 531 391-3283
EMail: [email protected]

Levi & Schoenwaelder Standards Track [Page 24]

RFC 2591 Scheduling MIB May 1999

11. Full Copyright Statement

Copyright (C) The Internet Society (1999). 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.

Levi & Schoenwaelder Standards Track [Page 25]