WDIFF

draft-ops-smiv2-smi-01.txt --> rfc2578.txt

Network Working Group Editors of this version:
Internet Draft
Request for Comments: 2578 K. McCloghrie
STD: 58 Cisco Systems
Obsoletes: 1902 D. Perkins
Desktalk Systems &
Category: Standards Track SNMPinfo
J. Schoenwaelder
TU Braunschweig
Authors of previous version:
J. Case
SNMP Research
K. McCloghrie
Cisco Systems
M. Rose
First Virtual Holdings
S. Waldbusser
International Network Services
30 January
April 1999

Structure of Management Information Version 2 (SMIv2)
draft-ops-smiv2-smi-01.txt

Status of this Memo

This document is specifies an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026. Internet-Drafts are working
documents of Internet standards track protocol for the
Internet Engineering Task Force (IETF), its areas, community, and
its working groups. Note that other groups may also distribute working
documents as Internet-Drafts.

Internet-Drafts are draft documents valid for a maximum of six months requests discussion and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference material
or suggestions for
improvements. Please refer to cite them other than as ``work in progress.''

To view the current status edition of any Internet-Draft, please check the
``1id-abstracts.txt'' listing contained in an Internet-Drafts Shadow
Directory, see http://www.ietf.org/shadow.html. "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.

Expires July 1999

Table of Contents

1 Introduction .................................................3
1.1 A Note on Terminology ......................................4
2 Definitions ..................................................4
2.1 The MODULE-IDENTITY macro ..................................5
2.2 Object Names and Syntaxes ..................................5
2.3 The OBJECT-TYPE macro ......................................8
2.5 The NOTIFICATION-TYPE macro ...............................10
2.6 Administrative Identifiers ................................11
3 Information Modules .........................................11
3.1 Macro Invocation ..........................................12
3.1.1 Textual Values and Strings ..............................13

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RFC 2578 SMIv2 January April 1999

1. Introduction

Management information is viewed as a collection

3.2 IMPORTing Symbols .........................................14
3.3 Exporting Symbols .........................................14
3.4 ASN.1 Comments ............................................14
3.5 OBJECT IDENTIFIER values ..................................15
3.6 OBJECT IDENTIFIER usage ...................................15
3.7 Reserved Keywords .........................................16
4 Naming Hierarchy ............................................16
5 Mapping of managed objects,
residing in a virtual information store, termed the Management
Information Base (MIB). Collections MODULE-IDENTITY macro ........................17
5.1 Mapping of related objects are defined in
MIB modules. These modules are written using an adapted subset the LAST-UPDATED clause ........................17
5.2 Mapping of OSI's
Abstract Syntax Notation One, ASN.1 (1988) [1]. It is the purpose ORGANIZATION clause ........................17
5.3 Mapping of
this document, the Structure CONTACT-INFO clause ........................18
5.4 Mapping of Management Information (SMI), to define
that adapted subset, and to assign a set the DESCRIPTION clause .........................18
5.5 Mapping of associated administrative
values.

The SMI is divided into three parts: module definitions, object
definitions, and, notification definitions.

(1) Module definitions are used when describing information modules.
An ASN.1 macro, MODULE-IDENTITY, is used to concisely convey the
semantics REVISION clause ............................18
5.5.1 Mapping of an information module.

(2) Object definitions are used when describing managed objects. An
ASN.1 macro, OBJECT-TYPE, is used to concisely convey the syntax
and semantics DESCRIPTION sub-clause ...................18
5.6 Mapping of a managed object.

(3) Notification definitions are used when describing unsolicited
transmissions the MODULE-IDENTITY value ......................18
5.7 Usage Example .............................................18
6 Mapping of management information. An ASN.1 macro,
NOTIFICATION-TYPE, is used to concisely convey the syntax and
semantics OBJECT-IDENTITY macro ........................19
6.1 Mapping of a notification.

1.1. A Note on Terminology

For the purpose STATUS clause ..............................19
6.2 Mapping of exposition, the original Structure DESCRIPTION clause .........................20
6.3 Mapping of Management
Information, as described in RFCs 1155 (STD 16), 1212 (STD 16), and RFC
1215, is termed the SMI version 1 (SMIv1). The current version REFERENCE clause ...........................20
6.4 Mapping of the
Structure OBJECT-IDENTITY value ......................20
6.5 Usage Example .............................................20
7 Mapping of Management Information is termed SMI version 2 (SMIv2).

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2. Definitions

SNMPv2-SMI DEFINITIONS ::= BEGIN

-- the path to OBJECT-TYPE macro ............................20
7.1 Mapping of the root

org OBJECT IDENTIFIER ::= { iso 3 }
dod OBJECT IDENTIFIER ::= { org 6 }
internet OBJECT IDENTIFIER ::= { dod 1 }

directory OBJECT IDENTIFIER ::= { internet 1 }

mgmt OBJECT IDENTIFIER ::= { internet 2 }
mib-2 OBJECT IDENTIFIER ::= { mgmt 1 }
transmission OBJECT IDENTIFIER ::= { mib-2 10 }

experimental OBJECT IDENTIFIER ::= { internet 3 }

private SYNTAX clause ..............................21
7.1.1 Integer32 and INTEGER ...................................21
7.1.2 OCTET STRING ............................................21
7.1.3 OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { private 1 }

security OBJECT IDENTIFIER ::= { internet 5 }

snmpV2 OBJECT IDENTIFIER ::= { internet 6 }

-- transport domains
snmpDomains OBJECT IDENTIFIER ::= { snmpV2 1 }

-- transport proxies
snmpProxys OBJECT IDENTIFIER ::= { snmpV2 2 }

-- module identities
snmpModules OBJECT IDENTIFIER ::= { snmpV2 3 }

Expires July 1999 .......................................22
7.1.4 The BITS construct ......................................22
7.1.5 IpAddress ...............................................22
7.1.6 Counter32 ...............................................23
7.1.7 Gauge32 .................................................23
7.1.8 TimeTicks ...............................................24
7.1.9 Opaque ..................................................24
7.1.10 Counter64 ..............................................24
7.1.11 Unsigned32 .............................................25
7.1.12 Conceptual Tables ......................................25
7.1.12.1 Creation and Deletion of Conceptual Rows .............26
7.2 Mapping of the UNITS clause ...............................26
7.3 Mapping of the MAX-ACCESS clause ..........................26
7.4 Mapping of the STATUS clause ..............................27
7.5 Mapping of the DESCRIPTION clause .........................27
7.6 Mapping of the REFERENCE clause ...........................27
7.7 Mapping of the INDEX clause ...............................27
7.8 Mapping of the AUGMENTS clause ............................29
7.8.1 Relation between INDEX and AUGMENTS clauses .............30
7.9 Mapping of the DEFVAL clause ..............................30
7.10 Mapping of the OBJECT-TYPE value .........................31
7.11 Usage Example ............................................32

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RFC 2578 SMIv2 January April 1999

-- Extended UTCTime, to allow dates with four-digit years
-- (Note that this definition

8 Mapping of ExtUTCTime is not to be IMPORTed
-- by MIB modules.)
ExtUTCTime ::= OCTET STRING(SIZE(11 | 13))
-- format is YYMMDDHHMMZ or YYYYMMDDHHMMZ
-- where: YY - last two digits the NOTIFICATION-TYPE macro ......................34
8.1 Mapping of year (only years
-- between 1900-1999)
-- YYYY - last four digits the OBJECTS clause .............................34
8.2 Mapping of the year (any year)
-- MM - month (01 through 12)
-- DD - day STATUS clause ..............................34
8.3 Mapping of month (01 through 31)
-- HH - hours (00 through 23)
-- MM - minutes (00 through 59)
-- Z - denotes GMT (the ASCII character Z)
--
-- For example, "9502192015Z" and "199502192015Z" represent
-- 8:15pm GMT on 19 February 1995. Years after 1999 must use
-- the four digit year format. Years 1900-1999 may use DESCRIPTION clause .........................35
8.4 Mapping of the
-- two or four digit format.

-- definitions for REFERENCE clause ...........................35
8.5 Mapping of the NOTIFICATION-TYPE value ....................35
8.6 Usage Example .............................................35
9 Refined Syntax ..............................................36
10 Extending an Information Module ............................37
10.1 Object Assignments .......................................37
10.2 Object Definitions .......................................38
10.3 Notification Definitions .................................39
11 Appendix A: Detailed Sub-typing Rules ......................40
11.1 Syntax Rules .............................................40
11.2 Examples .................................................41
12 Security Considerations ....................................41
13 Editors' Addresses .........................................41
14 References .................................................42
15 Full Copyright Statement ...................................43

1. Introduction

Management information modules

MODULE-IDENTITY MACRO ::=
BEGIN
TYPE NOTATION ::=
"LAST-UPDATED" value(Update ExtUTCTime)
"ORGANIZATION" Text
"CONTACT-INFO" Text
"DESCRIPTION" Text
RevisionPart

VALUE NOTATION ::=
value(VALUE OBJECT IDENTIFIER)

RevisionPart ::=
Revisions
| empty
Revisions ::=
Revision
| Revisions Revision
Revision ::=
"REVISION" value(Update ExtUTCTime)
"DESCRIPTION" Text

-- a character string is viewed as defined in section 3.1.1
Text ::= value(IA5String)

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END

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OBJECT-IDENTITY MACRO ::=
BEGIN
TYPE NOTATION ::=
"STATUS" Status
"DESCRIPTION" Text
ReferPart

VALUE NOTATION ::=
value(VALUE OBJECT IDENTIFIER)

Status ::=
"current"
| "deprecated"
| "obsolete"

ReferPart ::=
"REFERENCE" Text
| empty

-- a character string as defined collection of managed objects,
residing in section 3.1.1
Text ::= value(IA5String)
END

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-- names a virtual information store, termed the Management
Information Base (MIB). Collections of related objects
-- (Note that these definitions of ObjectName and NotificationName
-- are not to be IMPORTed by defined
in MIB modules.)

ObjectName ::=
OBJECT IDENTIFIER

NotificationName ::=
OBJECT IDENTIFIER

-- syntax modules. These modules are written using an adapted subset of objects

-- the "base types" defined here are:
-- 3 built-in
OSI's Abstract Syntax Notation One, ASN.1 types: INTEGER, OCTET STRING, OBJECT IDENTIFIER
-- 8 application-defined types: Integer32, IpAddress, Counter32,
-- Gauge32, Unsigned32, TimeTicks, Opaque, and Counter64

ObjectSyntax ::=
CHOICE {
simple
SimpleSyntax,

-- note (1988) [1]. It is the
purpose of this document, the Structure of Management Information
(SMI), to define that SEQUENCEs for conceptual tables adapted subset, and
-- rows to assign a set of
associated administrative values.

The SMI is divided into three parts: module definitions, object
definitions, and, notification definitions.

(1) Module definitions are not mentioned here...

application-wide
ApplicationSyntax
}

-- built-in used when describing information modules.
An ASN.1 types

SimpleSyntax ::=
CHOICE {
-- INTEGERs with a more restrictive range
-- may also be macro, MODULE-IDENTITY, is used
integer-value -- includes Integer32
INTEGER (-2147483648..2147483647),

-- OCTET STRINGs with to concisely convey the
semantics of an information module.

(2) Object definitions are used when describing managed objects. An
ASN.1 macro, OBJECT-TYPE, is used to concisely convey the syntax
and semantics of a more restrictive size
-- may also be managed object.

(3) Notification definitions are used
string-value
OCTET STRING (SIZE (0..65535)),

objectID-value
OBJECT IDENTIFIER

Expires July 1999 when describing unsolicited
transmissions of management information. An ASN.1 macro,
NOTIFICATION-TYPE, is used to concisely convey the syntax and
semantics of a notification.

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RFC 2578 SMIv2 January April 1999

}

-- indistinguishable from INTEGER, but never needs more than
-- 32-bits for a two's complement representation
Integer32

1.1. A Note on Terminology

For the purpose of exposition, the original Structure of Management
Information, as described in RFCs 1155 (STD 16), 1212 (STD 16), and
RFC 1215, is termed the SMI version 1 (SMIv1). The current version
of the Structure of Management Information is termed SMI version 2
(SMIv2).

2. Definitions

SNMPv2-SMI DEFINITIONS ::=
INTEGER (-2147483648..2147483647) BEGIN

-- application-wide types

ApplicationSyntax the path to the root

org OBJECT IDENTIFIER ::=
CHOICE {
ipAddress-value
IpAddress,

counter-value
Counter32,

timeticks-value
TimeTicks,

arbitrary-value
Opaque,

big-counter-value
Counter64,

unsigned-integer-value -- includes Gauge32
Unsigned32 iso 3 } -- in network-byte order
-- (this is a tagged type for historical reasons)
IpAddress ::=
[APPLICATION 0]
IMPLICIT OCTET STRING (SIZE (4))

-- this wraps
Counter32 "iso" = 1
dod OBJECT IDENTIFIER ::=
[APPLICATION 1]
IMPLICIT INTEGER (0..4294967295)

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-- this doesn't wrap
Gauge32 { org 6 }
internet OBJECT IDENTIFIER ::=
[APPLICATION 2]
IMPLICIT INTEGER (0..4294967295)

-- an unsigned 32-bit quantity
-- indistinguishable from Gauge32
Unsigned32 { dod 1 }

directory OBJECT IDENTIFIER ::=
[APPLICATION 2]
IMPLICIT INTEGER (0..4294967295)

-- hundredths of seconds since an epoch
TimeTicks { internet 1 }

mgmt OBJECT IDENTIFIER ::=
[APPLICATION 3]
IMPLICIT INTEGER (0..4294967295)

-- for backward-compatibility only
Opaque { internet 2 }
mib-2 OBJECT IDENTIFIER ::=
[APPLICATION 4]
IMPLICIT OCTET STRING

-- for counters that wrap in less than one hour with only 32 bits
Counter64 { mgmt 1 }
transmission OBJECT IDENTIFIER ::=
[APPLICATION 6]
IMPLICIT INTEGER (0..18446744073709551615)

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-- definition for objects

OBJECT-TYPE MACRO { mib-2 10 }

experimental OBJECT IDENTIFIER ::=
BEGIN
TYPE NOTATION { internet 3 }

private OBJECT IDENTIFIER ::=
"SYNTAX" Syntax
UnitsPart
"MAX-ACCESS" Access
"STATUS" Status
"DESCRIPTION" Text
ReferPart
IndexPart
DefValPart

VALUE NOTATION { internet 4 }
enterprises OBJECT IDENTIFIER ::=
value(VALUE ObjectName)

Syntax { private 1 }

security OBJECT IDENTIFIER ::= { internet 5 }

snmpV2 OBJECT IDENTIFIER ::= { internet 6 }

-- Must be one of the following:
-- a base type (or its refinement),
-- a textual convention (or its refinement), or transport domains
snmpDomains OBJECT IDENTIFIER ::= { snmpV2 1 }

-- a BITS pseudo-type
type
| "BITS" "{" NamedBits "}"

NamedBits transport proxies
snmpProxys OBJECT IDENTIFIER ::= NamedBit
| NamedBits "," NamedBit

NamedBit { snmpV2 2 }

-- module identities
snmpModules OBJECT IDENTIFIER ::= identifier "(" number ")" { snmpV2 3 }

-- number Extended UTCTime, to allow dates with four-digit years
-- (Note that this definition of ExtUTCTime is nonnegative

UnitsPart ::=
"UNITS" Text
| empty

Access ::=
"not-accessible"
| "accessible-for-notify"
| "read-only"
| "read-write"
| "read-create"

Status not to be IMPORTed
-- by MIB modules.)
ExtUTCTime ::=
"current"
| "deprecated" OCTET STRING(SIZE(11 | "obsolete"

Expires July 1999 13))
-- format is YYMMDDHHMMZ or YYYYMMDDHHMMZ

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RFC 2578 SMIv2 January April 1999

ReferPart ::=
"REFERENCE" Text
| empty

IndexPart ::=
"INDEX" "{" IndexTypes "}"
| "AUGMENTS" "{" Entry "}"
| empty
IndexTypes ::=
IndexType
| IndexTypes "," IndexType
IndexType ::=
"IMPLIED" Index
| Index
Index ::=

-- use the SYNTAX value where: YY - last two digits of the year (only years
-- correspondent OBJECT-TYPE invocation
value(ObjectName)
Entry ::= between 1900-1999)
-- use the INDEX value YYYY - last four digits of the year (any year)
-- correspondent OBJECT-TYPE invocation
value(ObjectName)

DefValPart ::= "DEFVAL" "{" Defvalue "}"
| empty

Defvalue ::= MM - month (01 through 12)
-- DD - day of month (01 through 31)
-- HH - hours (00 through 23)
-- MM - minutes (00 through 59)
-- Z - denotes GMT (the ASCII character Z)
--
-- For example, "9502192015Z" and "199502192015Z" represent
-- 8:15pm GMT on 19 February 1995. Years after 1999 must be valid for use
-- the four digit year format. Years 1900-1999 may use the type specified in
-- SYNTAX clause of same OBJECT-TYPE macro
value(ObjectSyntax)
| "{" BitsValue "}"

BitsValue two or four digit format.

-- definitions for information modules

MODULE-IDENTITY MACRO ::= BitNames
BEGIN
TYPE NOTATION ::=
"LAST-UPDATED" value(Update ExtUTCTime)
"ORGANIZATION" Text
"CONTACT-INFO" Text
"DESCRIPTION" Text
RevisionPart

VALUE NOTATION ::=
value(VALUE OBJECT IDENTIFIER)

RevisionPart ::=
Revisions
| empty

BitNames
Revisions ::= BitName
Revision
| BitNames "," BitName

BitName Revisions Revision
Revision ::= identifier
"REVISION" value(Update ExtUTCTime)
"DESCRIPTION" Text

-- a character string as defined in section 3.1.1
Text ::= value(IA5String)
END

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-- definitions for notifications

NOTIFICATION-TYPE

OBJECT-IDENTITY MACRO ::=
BEGIN
TYPE NOTATION ::=
ObjectsPart
"STATUS" Status
"DESCRIPTION" Text

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RFC 2578 SMIv2 April 1999

ReferPart

VALUE NOTATION ::=
value(VALUE NotificationName)

ObjectsPart ::=
"OBJECTS" "{" Objects "}"
| empty
Objects ::=
Object
| Objects "," Object
Object ::=
value(ObjectName) OBJECT IDENTIFIER)

Status ::=
"current"
| "deprecated"
| "obsolete"

ReferPart ::=
"REFERENCE" Text
| empty

-- a character string as defined in section 3.1.1
Text ::= value(IA5String)
END

-- definitions names of administrative identifiers

zeroDotZero OBJECT-IDENTITY
STATUS current
DESCRIPTION
"A value used for null identifiers."
::= { 0 0 }

END

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3. Information Modules

An "information module" is an ASN.1 module defining information relating
to network management.

The SMI describes how to use an adapted subset objects
-- (Note that these definitions of ASN.1 (1988) ObjectName and NotificationName
-- are not to define
an information module. Further, additional restrictions are placed on
"standard" information modules. It is strongly recommended that
"enterprise-specific" information modules also adhere to these
restrictions.

Typically, there are three kinds of information modules:

(1) be IMPORTed by MIB modules, which contain definitions of inter-related managed
objects, make use modules.)

ObjectName ::=
OBJECT IDENTIFIER

NotificationName ::=
OBJECT IDENTIFIER

-- syntax of objects

-- the OBJECT-TYPE "base types" defined here are:
-- 3 built-in ASN.1 types: INTEGER, OCTET STRING, OBJECT IDENTIFIER
-- 8 application-defined types: Integer32, IpAddress, Counter32,
-- Gauge32, Unsigned32, TimeTicks, Opaque, and NOTIFICATION-TYPE macros;

(2) compliance statements Counter64

ObjectSyntax ::=
CHOICE {
simple
SimpleSyntax,

-- note that SEQUENCEs for MIB modules, which make use of the
MODULE-COMPLIANCE conceptual tables and OBJECT-GROUP macros [2]; and,

(3) capability statements for agent implementations which make use of
the AGENT-CAPABILITIES macros [2].

This classification scheme does
-- rows are not imply a rigid taxonomy. For
example, a "standard" information module will normally include
definitions of managed objects and a compliance statement. Similarly,
an "enterprise-specific" information module might include definitions of
managed objects and mentioned here...

application-wide
ApplicationSyntax
}

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RFC 2578 SMIv2 April 1999

-- built-in ASN.1 types

SimpleSyntax ::=
CHOICE {
-- INTEGERs with a capability statement. Of course, more restrictive range
-- may also be used
integer-value -- includes Integer32
INTEGER (-2147483648..2147483647),

-- OCTET STRINGs with a "standard"
information module more restrictive size
-- may not contain capability statements.

The constructs of ASN.1 allowed in SMIv2 information modules include:
the IMPORTS clause, value definitions for also be used
string-value
OCTET STRING (SIZE (0..65535)),

objectID-value
OBJECT IDENTIFIERs, type
definitions IDENTIFIER
}

-- indistinguishable from INTEGER, but never needs more than
-- 32-bits for SEQUENCEs (with restrictions), ASN.1 type assignments of
the restricted ASN.1 a two's complement representation
Integer32 ::=
INTEGER (-2147483648..2147483647)

-- application-wide types allowed in SMIv2, and instances of ASN.1
macros defined in this document and its companion documents [2, 3].
Additional ASN.1 macros must not be defined

ApplicationSyntax ::=
CHOICE {
ipAddress-value
IpAddress,

counter-value
Counter32,

timeticks-value
TimeTicks,

arbitrary-value
Opaque,

big-counter-value
Counter64,

unsigned-integer-value -- includes Gauge32
Unsigned32
}

-- in network-byte order

McCloghrie, et al. Standards Track [Page 7]

RFC 2578 SMIv2 information
modules. SMIv1 macros must not be used April 1999

-- (this is a tagged type for historical reasons)
IpAddress ::=
[APPLICATION 0]
IMPLICIT OCTET STRING (SIZE (4))

-- this wraps
Counter32 ::=
[APPLICATION 1]
IMPLICIT INTEGER (0..4294967295)

-- this doesn't wrap
Gauge32 ::=
[APPLICATION 2]
IMPLICIT INTEGER (0..4294967295)

-- an unsigned 32-bit quantity
-- indistinguishable from Gauge32
Unsigned32 ::=
[APPLICATION 2]
IMPLICIT INTEGER (0..4294967295)

-- hundredths of seconds since an epoch
TimeTicks ::=
[APPLICATION 3]
IMPLICIT INTEGER (0..4294967295)

-- for backward-compatibility only
Opaque ::=
[APPLICATION 4]
IMPLICIT OCTET STRING

-- for counters that wrap in less than one hour with only 32 bits
Counter64 ::=
[APPLICATION 6]
IMPLICIT INTEGER (0..18446744073709551615)

-- definition for objects

OBJECT-TYPE MACRO ::=
BEGIN
TYPE NOTATION ::=
"SYNTAX" Syntax
UnitsPart
"MAX-ACCESS" Access
"STATUS" Status
"DESCRIPTION" Text
ReferPart

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RFC 2578 SMIv2 information modules.

The names of all standard information modules must April 1999

IndexPart
DefValPart

VALUE NOTATION ::=
value(VALUE ObjectName)

Syntax ::= -- Must be unique (but
different versions one of the same information module should have the same
name). Developers of enterprise information modules are encouraged to
choose names for their information modules that will have following:
-- a low
probability of colliding with standard base type (or its refinement),
-- a textual convention (or its refinement), or other enterprise information
modules. An information module may not use the ASN.1 construct of
placing an object
-- a BITS pseudo-type
type
| "BITS" "{" NamedBits "}"

NamedBits ::= NamedBit
| NamedBits "," NamedBit

NamedBit ::= identifier value between the module name and the
"DEFINITIONS" keyword. For the purposes of this specification, an ASN.1

Expires July 1999 "(" number ")" -- number is nonnegative

UnitsPart ::=
"UNITS" Text
| empty

Access ::=
"not-accessible"
| "accessible-for-notify"
| "read-only"
| "read-write"
| "read-create"

Status ::=
"current"
| "deprecated"
| "obsolete"

ReferPart ::=
"REFERENCE" Text
| empty

IndexPart ::=
"INDEX" "{" IndexTypes "}"
| "AUGMENTS" "{" Entry "}"
| empty
IndexTypes ::=
IndexType
| IndexTypes "," IndexType
IndexType ::=
"IMPLIED" Index
| Index

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RFC 2578 SMIv2 January April 1999

module name begins with an upper-case letter and continues with zero or
more letters, digits, or hyphens, except that a hyphen can not be

Index ::=
-- use the
last character, nor can there be two consecutive hyphens.

All information modules start with exactly one invocation SYNTAX value of the
MODULE-IDENTITY macro, which provides contact information as well as
revision history to distinguish between versions
-- correspondent OBJECT-TYPE invocation
value(ObjectName)
Entry ::=
-- use the INDEX value of the same information
module. This
-- correspondent OBJECT-TYPE invocation
value(ObjectName)

DefValPart ::= "DEFVAL" "{" Defvalue "}"
| empty

Defvalue ::= -- must appear immediately after any IMPORTs
statements.

3.1. Macro Invocation

Within an information module, each macro invocation appears as:

where <descriptor> corresponds to an ASN.1 identifier, <macro> names the
macro being invoked, and <clauses> and <value> depend on the definition
of the macro. (Note that this definition of a descriptor applies to all
macros defined in this memo and in [2].)

For the purposes of this specification, an ASN.1 identifier consists of
one or more letters or digits, and its initial character must be a
lower-case letter. Note that hyphens are not allowed by this
specification (except for use by information modules converted from
SMIv1 which did allow hyphens).

For all descriptors appearing in an information module, the descriptor
shall be unique and mnemonic, and shall not exceed 64 characters in
length. (However, descriptors longer than 32 characters are not
recommended.) This promotes a common language valid for humans to use when
discussing the information module and also facilitates simple table
mappings for user-interfaces.

The set of descriptors defined type specified in all "standard" information modules
shall be unique.

Finally, by convention, if the descriptor refers to an object with a
-- SYNTAX clause value of either Counter32 or Counter64, then the
descriptor used for the object should denote plurality.

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Draft SMIv2 January 1999

3.1.1. Textual Values and Strings

Some clauses in a same OBJECT-TYPE macro invocation may take
value(ObjectSyntax)
| "{" BitsValue "}"

BitsValue ::= BitNames
| empty

BitNames ::= BitName
| BitNames "," BitName

BitName ::= identifier

-- a character string as defined in section 3.1.1
Text ::= value(IA5String)
END

-- definitions for notifications

NOTIFICATION-TYPE MACRO ::=
BEGIN
TYPE NOTATION ::=
ObjectsPart
"STATUS" Status
"DESCRIPTION" Text
ReferPart

VALUE NOTATION ::=
value(VALUE NotificationName)

ObjectsPart ::=
"OBJECTS" "{" Objects "}"
| empty
Objects ::=
Object

McCloghrie, et al. Standards Track [Page 10]

RFC 2578 SMIv2 April 1999

| Objects "," Object
Object ::=
value(ObjectName)

Status ::=
"current"
| "deprecated"
| "obsolete"

ReferPart ::=
"REFERENCE" Text
| empty

-- a
textual value (e.g., the DESCRIPTION clause). Other clauses take binary
or hexadecimal strings (in any position where a non-negative number is
allowed).

A character string is preceded and followed by the quote character ("),
and consists as defined in section 3.1.1
Text ::= value(IA5String)
END

-- definitions of administrative identifiers

zeroDotZero OBJECT-IDENTITY
STATUS current
DESCRIPTION
"A value used for null identifiers."
::= { 0 0 }

END

3. Information Modules

An "information module" is an arbitrary number (possibly zero) of:

- any 7-bit displayable ASCII characters except quote ("),
- tab characters,
- spaces, and
- line terminator characters (\n or \r\n). ASN.1 module defining information
relating to network management.

The value SMI describes how to use an adapted subset of a character string ASN.1 (1988) to
define an information module. Further, additional restrictions are
placed on "standard" information modules. It is interpreted as ASCII.

A binary string consists strongly recommended
that "enterprise-specific" information modules also adhere to these
restrictions.

Typically, there are three kinds of a number (possibly zero) information modules:

(1) MIB modules, which contain definitions of inter-related managed
objects, make use of zeros and ones
preceded by a single (') and followed by either the pair ('B) or ('b),
where the number is a multiple of eight.

A hexadecimal string consists of an even number (possibly zero) of
hexadecimal digits, preceded by a single (') OBJECT-TYPE and followed by either the
pair ('H) or ('h). Digits specified via letters can be in upper or
lower case.

Note that ASN.1 comments can not be enclosed inside any of these types NOTIFICATION-TYPE macros;

(2) compliance statements for MIB modules, which make use of strings.

3.2. IMPORTing Symbols

To reference an external object, the IMPORTS statement must be used to
identify both the descriptor
MODULE-COMPLIANCE and the module in OBJECT-GROUP macros [2]; and,

(3) capability statements for agent implementations which make use of
the descriptor is
defined, where the module is identified by its ASN.1 module name.

Note that when symbols from "enterprise-specific" information modules
are referenced (e.g., AGENT-CAPABILITIES macros [2].

McCloghrie, et al. Standards Track [Page 11]

RFC 2578 SMIv2 April 1999

This classification scheme does not imply a descriptor), there is the possibility rigid taxonomy. For
example, a "standard" information module will normally include
definitions of
collision. As such, if different managed objects with the same descriptor are
IMPORTed, then this ambiguity is resolved by prefixing the descriptor
with the name of the and a compliance statement.
Similarly, an "enterprise-specific" information module might include
definitions of managed objects and a dot ("."), i.e.,

"module.descriptor"

(All descriptors must be unique within any information module.)

Expires July 1999 [Page 15]

Draft SMIv2 January 1999 capability statement. Of
course, this notation can be used to refer to objects even when there
is no collision when IMPORTing symbols.

Finally, if any a "standard" information module may not contain capability
statements.

The constructs of the ASN.1 named types and macros defined in this
document, specifically:

Counter32, Counter64, Gauge32, Integer32, IpAddress, MODULE-
IDENTITY, NOTIFICATION-TYPE, Opaque, OBJECT-TYPE, OBJECT-IDENTITY,
TimeTicks, Unsigned32,

or any of those defined in [2] or [3], are used allowed in an SMIv2 information
module, then they must be imported using modules include:
the IMPORTS statement.
However, clause, value definitions for OBJECT IDENTIFIERs, type
definitions for SEQUENCEs (with restrictions), ASN.1 type assignments
of the following must not be included in an IMPORTS statement:

- named restricted ASN.1 types defined by allowed in SMIv2, and instances of
ASN.1 itself, specifically: INTEGER, OCTET
STRING, OBJECT IDENTIFIER, SEQUENCE, SEQUENCE OF type,
- the BITS construct.

3.3. Exporting Symbols

The macros defined in this document and its companion documents [2,
3]. Additional ASN.1 EXPORTS statement is macros must not allowed be defined in SMIv2 information
modules.
All items defined SMIv1 macros must not be used in an SMIv2 information modules.

The names of all standard information modules must be unique (but
different versions of the same information module should have the
same name). Developers of enterprise information modules are automatically exported.

3.4. ASN.1 Comments

ASN.1 comments can be included in an
encouraged to choose names for their information module. However, it is
recommended modules that all substantive descriptions be placed within an
appropriate DESCRIPTION clause.

ASN.1 comments commence with will
have a pair low probability of adjacent hyphens and end colliding with the
next pair of adjacent hyphens standard or at other enterprise
information modules. An information module may not use the end ASN.1
construct of placing an object identifier value between the line, whichever
occurs first. Comments ended by a pair of hyphens have module
name and the effect "DEFINITIONS" keyword. For the purposes of a
single space character.

3.5. OBJECT IDENTIFIER values

An OBJECT IDENTIFIER value is this
specification, an ordered list of non-negative numbers.
For ASN.1 module name begins with an upper-case letter
and continues with zero or more letters, digits, or hyphens, except
that a hyphen can not be the SMIv2, each number in last character, nor can there be two
consecutive hyphens.

All information modules start with exactly one invocation of the list is referred to
MODULE-IDENTITY macro, which provides contact information as a sub-
identifier, there are at most 128 sub-identifiers in a value, and each
sub-identifier has a maximum value well as
revision history to distinguish between versions of 2^32-1 (4294967295 decimal).

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Draft SMIv2 January 1999

All OBJECT IDENTIFIER values have at least two sub-identifiers, the same
information module. This invocation must appear immediately after
any IMPORTs statements.

3.1. Macro Invocation

Within an information module, each macro invocation appears as:

where <descriptor> corresponds to an ASN.1 identifier, <macro> names
the value of macro being invoked, and <clauses> and <value> depend on the first sub-identifier is one
definition of the following well-known
names:

Value Name
0 ccitt
1 iso
2 joint-iso-ccitt macro. (Note that this SMI does not recognize "new" well-known names, e.g., as definition of a descriptor
applies to all macros defined when the CCITT became the ITU.)

3.6. OBJECT IDENTIFIER usage

OBJECT IDENTIFIERs are used in information modules this memo and in two ways:

(1) registration: [2].)

McCloghrie, et al. Standards Track [Page 12]

RFC 2578 SMIv2 April 1999

For the definition purposes of this specification, an ASN.1 identifier consists
of one or more letters or digits, and its initial character must be a particular item is registered as
a particular OBJECT IDENTIFIER value, and associated with a
particular descriptor. After such a registration, the semantics
thereby associated with the value
lower-case letter. Note that hyphens are not allowed to change, the
OBJECT IDENTIFIER can not be used by this
specification (except for any other registration, and use by information modules converted from
SMIv1 which did allow hyphens).

For all descriptors appearing in an information module, the
descriptor can not shall be changed nor associated with any other
registration. The following macros result unique and mnemonic, and shall not exceed 64
characters in length. (However, descriptors longer than 32
characters are not recommended.) This promotes a registration:

OBJECT-TYPE, MODULE-IDENTITY, NOTIFICATION-TYPE, OBJECT-GROUP,
OBJECT-IDENTITY, NOTIFICATION-GROUP, MODULE-COMPLIANCE,
AGENT-CAPABILITIES.

(2) assignment: a descriptor can be assigned common language for
humans to a particular OBJECT
IDENTIFIER value. For this usage, the semantics associated with use when discussing the OBJECT IDENTIFIER value is not allowed to change, information module and a also
facilitates simple table mappings for user-interfaces.

The set of descriptors defined in all "standard" information modules
shall be unique.

Finally, by convention, if the descriptor assigned refers to an object with a particular OBJECT IDENTIFIER
SYNTAX clause value cannot
subsequently be assigned to another. However, multiple descriptors
can be assigned to of either Counter32 or Counter64, then the same OBJECT IDENTIFIER value. Such
assignments are specified
descriptor used for the object should denote plurality.

3.1.1. Textual Values and Strings

Some clauses in a macro invocation may take a character string as a
textual value (e.g., the following manner:

mib OBJECT IDENTIFIER ::= { mgmt 1 } -- from RFC1156
mib-2 OBJECT IDENTIFIER ::= { mgmt 1 } -- from RFC1213
fredRouter OBJECT IDENTIFIER ::= { flintStones 1 1 }
barneySwitch OBJECT IDENTIFIER ::= { flintStones bedrock(2) 1 }

Note while the above examples are legal, DESCRIPTION clause). Other clauses take
binary or hexadecimal strings (in any position where a non-negative
number is allowed).

A character string is preceded and followed by the following quote character
("), and consists of an arbitrary number (possibly zero) of:

- any 7-bit displayable ASCII characters except quote ("),
- tab characters,
- spaces, and
- line terminator characters (\n or \r\n).

The value of a character string is not:

dinoHost OBJECT IDENTIFIER ::= { flintStones bedrock 2 }

Expires July 1999 [Page 17]

Draft SMIv2 January 1999 interpreted as ASCII.

A descriptor binary string consists of a number (possibly zero) of zeros and
ones preceded by a single (') and followed by either the pair ('B) or
('b), where the number is allowed to be associated with both a registration multiple of eight.

A hexadecimal string consists of an even number (possibly zero) of
hexadecimal digits, preceded by a single (') and followed by either
the pair ('H) or ('h). Digits specified via letters can be in upper
or lower case.

Note that ASN.1 comments can not be enclosed inside any of these
types of strings.

McCloghrie, et al. Standards Track [Page 13]

RFC 2578 SMIv2 April 1999

3.2. IMPORTing Symbols

To reference an
assignment, providing both are associated with external object, the same OBJECT
IDENTIFIER value and semantics.

3.7. Reserved Keywords

The following are reserved keywords which IMPORTS statement must not be used as
descriptors or module names:

ABSENT ACCESS AGENT-CAPABILITIES ANY APPLICATION AUGMENTS BEGIN BIT
BITS BOOLEAN BY CHOICE COMPONENT COMPONENTS CONTACT-INFO CREATION-
REQUIRES Counter32 Counter64 DEFAULT DEFINED DEFINITIONS DEFVAL
DESCRIPTION DISPLAY-HINT END ENUMERATED ENTERPRISE EXPLICIT EXPORTS
EXTERNAL FALSE FROM GROUP Gauge32 IDENTIFIER IMPLICIT IMPLIED
IMPORTS INCLUDES INDEX INTEGER Integer32 IpAddress LAST-UPDATED
MANDATORY-GROUPS MAX MAX-ACCESS MIN MIN-ACCESS MINUS-INFINITY
MODULE MODULE-COMPLIANCE MODULE-IDENTITY NOTIFICATION-GROUP
NOTIFICATION-TYPE NOTIFICATIONS NULL OBJECT OBJECT-GROUP OBJECT-
IDENTITY OBJECT-TYPE OBJECTS OCTET OF OPTIONAL ORGANIZATION Opaque
PLUS-INFINITY PRESENT PRIVATE PRODUCT-RELEASE REAL REFERENCE
REVISION SEQUENCE SET SIZE STATUS STRING SUPPORTS SYNTAX TAGS
TEXTUAL-CONVENTION TRAP-TYPE TRUE TimeTicks UNITS UNIVERSAL
Unsigned32 VARIABLES VARIATION WITH WRITE-SYNTAX

Expires July 1999 [Page 18]

Draft SMIv2 January 1999

4. Naming Hierarchy

The root of
to identify both the subtree administered by descriptor and the Internet Assigned Numbers
Authority (IANA) for module in which the Internet is:

internet OBJECT IDENTIFIER ::= { iso 3 6 1 }

That is,
descriptor is defined, where the Internet subtree module is identified by its ASN.1
module name.

Note that when symbols from "enterprise-specific" information modules
are referenced (e.g., a descriptor), there is the possibility of OBJECT IDENTIFIERs starts
collision. As such, if different objects with the
prefix:

1.3.6.1.

Several branches underneath this subtree same descriptor
are used for network
management:

mgmt OBJECT IDENTIFIER ::= { internet 2 }
experimental OBJECT IDENTIFIER ::= { internet 3 }
private OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { private 1 }

However, IMPORTed, then this ambiguity is resolved by prefixing the SMI does not prohibit
descriptor with the definition of objects in other
portions name of the object tree.

The mgmt(2) subtree is used to identify "standard" objects.

The experimental(3) subtree is used to identify objects being designed
by working groups of the IETF. If an information module produced by a
working group becomes and a "standard" dot ("."),
i.e.,

"module.descriptor"

(All descriptors must be unique within any information module, then at the very
beginning of its entry onto the Internet standards track, the objects
are moved under the mgmt(2) subtree.

The private(4) subtree is module.)

Of course, this notation can be used to identify refer to objects defined unilaterally.
The enterprises(1) subtree beneath private even when
there is used, among other things,
to permit providers of networking subsystems to register models of their
products.

Expires July 1999 [Page 19]

Draft SMIv2 January 1999

5. Mapping no collision when IMPORTing symbols.

Finally, if any of the MODULE-IDENTITY macro

The MODULE-IDENTITY macro is used to provide contact ASN.1 named types and revision
history for each information module. It must appear exactly once macros defined in
every this
document, specifically:

Counter32, Counter64, Gauge32, Integer32, IpAddress, MODULE-
IDENTITY, NOTIFICATION-TYPE, Opaque, OBJECT-TYPE, OBJECT-
IDENTITY, TimeTicks, Unsigned32,

or any of those defined in [2] or [3], are used in an information module. It should
module, then they must be noted that imported using the expansion of IMPORTS statement.
However, the
MODULE-IDENTITY macro is something which conceptually happens during
implementation and following must not during run-time.

Note that reference be included in an IMPORTS clause or statement:

- named types defined by ASN.1 itself, specifically: INTEGER,
OCTET STRING, OBJECT IDENTIFIER, SEQUENCE, SEQUENCE OF type,
- the BITS construct.

3.3. Exporting Symbols

The ASN.1 EXPORTS statement is not allowed in clauses of SMIv2 macros
to information
modules. All items defined in an information module is NOT through the use of the 'descriptor' of a
MODULE-IDENTITY macro; rather, are
automatically exported.

3.4. ASN.1 Comments

ASN.1 comments can be included in an information module module. However, it
is referenced
through specifying its module name.

5.1. Mapping of the LAST-UPDATED clause

The LAST-UPDATED clause, which must be present, contains the date and
time recommended that this information module was last edited.

5.2. Mapping of the ORGANIZATION clause

The ORGANIZATION clause, which must all substantive descriptions be present, contains placed within an
appropriate DESCRIPTION clause.

McCloghrie, et al. Standards Track [Page 14]

RFC 2578 SMIv2 April 1999

ASN.1 comments commence with a textual
description of the organization under whose auspices this information
module was developed.

5.3. Mapping pair of the CONTACT-INFO clause

The CONTACT-INFO clause, which must be present, contains the name,
postal address, telephone number, adjacent hyphens and electronic mail address end with
the next pair of adjacent hyphens or at the
person to whom technical queries concerning this information module
should be sent.

5.4. Mapping end of the DESCRIPTION clause

The DESCRIPTION clause, which must be present, contains line,
whichever occurs first. Comments ended by a high-level
textual description pair of hyphens have the contents of this information module.

5.5. Mapping
effect of the REVISION clause

The REVISION clause, which need not be present, a single space character.

3.5. OBJECT IDENTIFIER values

An OBJECT IDENTIFIER value is repeatedly used to
describe an ordered list of non-negative
numbers. For the revisions (including SMIv2, each number in the initial version) made list is referred to this

Expires July 1999 [Page 20]

Draft SMIv2 January 1999

information module, in reverse chronological order (i.e., as a
sub-identifier, there are at most recent
first). Each instance of this clause contains the date 128 sub-identifiers in a value, and time of the
revision.

5.5.1. Mapping of the DESCRIPTION sub-clause

The DESCRIPTION sub-clause, which must be present for
each REVISION
clause, contains sub-identifier has a high-level textual description of the revision
identified in that REVISION clause.

5.6. Mapping maximum value of 2^32-1 (4294967295
decimal).

All OBJECT IDENTIFIER values have at least two sub-identifiers, where
the MODULE-IDENTITY value

The value of an invocation of the MODULE-IDENTITY macro first sub-identifier is an OBJECT
IDENTIFIER. As such, one of the following well-
known names:

Value Name
0 ccitt
1 iso
2 joint-iso-ccitt

(Note that this value may be authoritatively used SMI does not recognize "new" well-known names, e.g.,
as defined when
specifying an the CCITT became the ITU.)

3.6. OBJECT IDENTIFIER value to refer to the usage

OBJECT IDENTIFIERs are used in information module
containing the invocation.

Note that it is a common practice to use modules in two ways:

(1) registration: the value definition of the MODULE-
IDENTITY macro a particular item is registered as
a subtree under which other particular OBJECT IDENTIFIER values
assigned within value, and associated with a
particular descriptor. After such a registration, the module semantics
thereby associated with the value are defined. However, it is legal (and
occasionally necessary) for not allowed to change, the other
OBJECT IDENTIFIER values assigned
within can not be used for any other registration, and
the module to descriptor can not be unrelated changed nor associated with any other
registration. The following macros result in a registration:

OBJECT-TYPE, MODULE-IDENTITY, NOTIFICATION-TYPE, OBJECT-GROUP,
OBJECT-IDENTITY, NOTIFICATION-GROUP, MODULE-COMPLIANCE,
AGENT-CAPABILITIES.

(2) assignment: a descriptor can be assigned to a particular OBJECT
IDENTIFIER value. For this usage, the semantics associated with
the OBJECT IDENTIFIER value of the
MODULE-IDENTITY macro.

Expires July 1999 [Page 21]

Draft SMIv2 January 1999

5.7. Usage Example

Consider how is not allowed to change, and a skeletal MIB module might
descriptor assigned to a particular OBJECT IDENTIFIER value cannot
subsequently be constructed: e.g.,

FIZBIN-MIB DEFINITIONS ::= BEGIN

IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, experimental
FROM SNMPv2-SMI;

fizbin MODULE-IDENTITY
LAST-UPDATED "199505241811Z"
ORGANIZATION "IETF SNMPv2 Working Group"
CONTACT-INFO
" Marshall T. Rose

Postal: Dover Beach Consulting, Inc.
420 Whisman Court
Mountain View, CA 94043-2186
US

Tel: +1 415 968 1052
Fax: +1 415 968 2510

E-mail: mrose@dbc.mtview.ca.us"
DESCRIPTION
"The MIB module for entities implementing assigned to another. However, multiple descriptors
can be assigned to the xxxx
protocol."
REVISION "9505241811Z"
DESCRIPTION
"The latest version of this MIB module."
REVISION "9210070433Z"
DESCRIPTION
"The initial version of this MIB module, published same OBJECT IDENTIFIER value. Such
assignments are specified in the following manner:

McCloghrie, et al. Standards Track [Page 15]

RFC
yyyy." 2578 SMIv2 April 1999

mib OBJECT IDENTIFIER ::= { mgmt 1 } -- contact IANA for actual number from RFC1156
mib-2 OBJECT IDENTIFIER ::= { experimental xx mgmt 1 }

END

Expires July 1999 [Page 22]

Draft SMIv2 January 1999

6. Mapping of the OBJECT-IDENTITY macro

The OBJECT-IDENTITY macro is used to define information about an -- from RFC1213
fredRouter OBJECT IDENTIFIER assignment. All administrative ::= { flintStones 1 1 }
barneySwitch OBJECT IDENTIFIER assignments
which define a type identification value (see AutonomousType, a textual
convention defined in [3]) should be defined via the OBJECT-IDENTITY
macro. It should be noted that ::= { flintStones bedrock(2) 1 }

Note while the expansion of above examples are legal, the OBJECT-IDENTITY
macro following is something which conceptually happens during implementation and
not during run-time.

6.1. Mapping of the STATUS clause

The STATUS clause, which must be present, indicates whether this
definition is current or historic.

The value "current" means that the definition is current and valid. The
value "obsolete" means the definition not:

dinoHost OBJECT IDENTIFIER ::= { flintStones bedrock 2 }

A descriptor is obsolete and should not be
implemented and/or can allowed to be removed if previously implemented. While the
value "deprecated" also indicates associated with both a registration and
an obsolete definition, it permits
new/continued implementation in order to foster interoperability assignment, providing both are associated with
older/existing implementations.

6.2. Mapping of the DESCRIPTION clause same OBJECT
IDENTIFIER value and semantics.

3.7. Reserved Keywords

The DESCRIPTION clause, following are reserved keywords which must be present, contains a textual
description of the object assignment.

6.3. Mapping of the REFERENCE clause

The REFERENCE clause, which need not be present, contains a textual
cross-reference to some other document, either another information
module which defines a related assignment, used as
descriptors or some other document which
provides additional information relevant to this definition.

6.4. Mapping of the OBJECT-IDENTITY value

The value of an invocation of the OBJECT-IDENTITY macro is an OBJECT
IDENTIFIER.

Expires July 1999 [Page 23]

Draft SMIv2 January 1999

6.5. Usage Example

Consider how an OBJECT module names:

fizbin69 IMPLICIT IMPLIED IMPORTS INCLUDES INDEX INTEGER
Integer32 IpAddress LAST-UPDATED MANDATORY-GROUPS MAX MAX-ACCESS
MIN MIN-ACCESS MINUS-INFINITY MODULE MODULE-COMPLIANCE MODULE-
IDENTITY NOTIFICATION-GROUP NOTIFICATION-TYPE NOTIFICATIONS NULL
OBJECT OBJECT-GROUP OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The authoritative identity OBJECT-TYPE OBJECTS OCTET OF
OPTIONAL ORGANIZATION Opaque PLUS-INFINITY PRESENT PRIVATE
PRODUCT-RELEASE REAL REFERENCE REVISION SEQUENCE SET SIZE STATUS
STRING SUPPORTS SYNTAX TAGS TEXTUAL-CONVENTION TRAP-TYPE TRUE
TimeTicks UNITS UNIVERSAL Unsigned32 VARIABLES VARIATION WITH
WRITE-SYNTAX

4. Naming Hierarchy

The root of the Fizbin 69 chipset." subtree administered by the Internet Assigned Numbers
Authority (IANA) for the Internet is:

internet OBJECT IDENTIFIER ::= { fizbinChipSets iso 3 6 1 }

Expires July 1999

That is, the Internet subtree of OBJECT IDENTIFIERs starts with the
prefix:

1.3.6.1.

Several branches underneath this subtree are used for network
management:

McCloghrie, et al. Standards Track [Page 24]

Draft 16]

RFC 2578 SMIv2 January April 1999

7. Mapping

mgmt OBJECT IDENTIFIER ::= { internet 2 }
experimental OBJECT IDENTIFIER ::= { internet 3 }
private OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { private 1 }

However, the SMI does not prohibit the definition of objects in other
portions of the OBJECT-TYPE macro object tree.

The OBJECT-TYPE macro mgmt(2) subtree is used to define a type of managed object. It
should be noted that the expansion of the OBJECT-TYPE macro identify "standard" objects.

The experimental(3) subtree is something
which conceptually happens during implementation and not during run-
time.

For leaf objects which are not columnar used to identify objects (i.e., not contained
within a conceptual table), instances being
designed by working groups of the object are identified IETF. If an information module
produced by
appending a sub-identifier of zero to working group becomes a "standard" information module,
then at the name very beginning of that object.
Otherwise, its entry onto the INDEX clause of Internet standards
track, the conceptual row object superior to a
columnar object defines instance identification information.

7.1. Mapping of objects are moved under the SYNTAX clause mgmt(2) subtree.

The SYNTAX clause, which must be present, defines the abstract data
structure corresponding private(4) subtree is used to that object. identify objects defined
unilaterally. The data structure must be one enterprises(1) subtree beneath private is used,
among other things, to permit providers of networking subsystems to
register models of their products.

5. Mapping of the following: a base type, the BITS construct, or a textual
convention. (SEQUENCE OF MODULE-IDENTITY macro

The MODULE-IDENTITY macro is used to provide contact and SEQUENCE are also possible revision
history for conceptual
tables, see section 7.1.12). The base types are those defined each information module. It must appear exactly once in
every information module. It should be noted that the
ObjectSyntax CHOICE. A textual convention expansion of
the MODULE-IDENTITY macro is a newly-defined type
defined as a sub-type something which conceptually happens
during implementation and not during run-time.

Note that reference in an IMPORTS clause or in clauses of a base type [3].

An extended subset SMIv2
macros to an information module is NOT through the use of the full capabilities
'descriptor' of ASN.1 (1988) sub-typing a MODULE-IDENTITY macro; rather, an information
module is allowed, as appropriate to referenced through specifying its module name.

5.1. Mapping of the underlying ASN.1 type. Any such
restriction on size, range or enumerations specified in this LAST-UPDATED clause
represents the maximal level of support

The LAST-UPDATED clause, which makes "protocol sense".
Restrictions on sub-typing are specified in detail in Section 9 must be present, contains the date and
Appendix A of
time that this memo.

The semantics information module was last edited.

5.2. Mapping of ObjectSyntax are now described.

7.1.1. Integer32 and INTEGER the ORGANIZATION clause

The Integer32 type represents integer-valued ORGANIZATION clause, which must be present, contains a textual
description of the organization under whose auspices this information between -2^31
and 2^31-1 inclusive (-2147483648 to 2147483647 decimal). This type is
indistinguishable from
module was developed.

McCloghrie, et al. Standards Track [Page 17]

RFC 2578 SMIv2 April 1999

5.3. Mapping of the INTEGER type. Both CONTACT-INFO clause

The CONTACT-INFO clause, which must be present, contains the INTEGER name,
postal address, telephone number, and Integer32
types may be sub-typed electronic mail address of the
person to whom technical queries concerning this information module
should be more constrained than sent.

5.4. Mapping of the Integer32 type. DESCRIPTION clause

The INTEGER type (but not DESCRIPTION clause, which must be present, contains a high-level
textual description of the Integer32 type) may also contents of this information module.

5.5. Mapping of the REVISION clause

The REVISION clause, which need not be present, is repeatedly used to
represent integer-valued
describe the revisions (including the initial version) made to this
information as named-number enumerations. In module, in reverse chronological order (i.e., most recent
first). Each instance of this case, only those named-numbers so enumerated may clause contains the date and time of
the revision.

5.5.1. Mapping of the DESCRIPTION sub-clause

The DESCRIPTION sub-clause, which must be present as for each REVISION
clause, contains a
value. Note that although it is recommended high-level textual description of the revision
identified in that enumerated values

Expires July 1999 [Page 25]

Draft SMIv2 January 1999

start at 1 and be numbered contiguously, any valid REVISION clause.

5.6. Mapping of the MODULE-IDENTITY value for Integer32
is allowed for an enumerated

The value and, further, enumerated values
needn't be contiguously assigned.

Finally, a label for a named-number enumeration must consist of one or
more letters or digits, up to a maximum an invocation of 64 characters, and the
initial character must MODULE-IDENTITY macro is an OBJECT
IDENTIFIER. As such, this value may be a lower-case letter. (However, labels longer
than 32 characters are not recommended.) authoritatively used when
specifying an OBJECT IDENTIFIER value to refer to the information
module containing the invocation.

Note that hyphens are not
allowed by this specification (except for it is a common practice to use by information modules
converted from SMIv1 which did allow hyphens).

7.1.2. OCTET STRING

The OCTET STRING type represents arbitrary binary or textual data.
Although the SMI-specified size limitation for this type is 65535
octets, MIB designers should realize that there may be implementation
and interoperability limitations for sizes in excess value of 255 octets.

7.1.3. the MODULE-
IDENTITY macro as a subtree under which other OBJECT IDENTIFIER

The
values assigned within the module are defined. However, it is legal
(and occasionally necessary) for the other OBJECT IDENTIFIER type represents administratively values
assigned names.
Any instance of this type may have at most 128 sub-identifiers.
Further, each sub-identifier must not exceed within the module to be unrelated to the OBJECT IDENTIFIER
value 2^32-1
(4294967295 decimal).

7.1.4. The BITS construct

The BITS construct represents an enumeration of named bits. This
collection is assigned non-negative, contiguous (but see below) values,
starting at zero. Only those named-bits so enumerated may be present in the MODULE-IDENTITY macro.

5.7. Usage Example

Consider how a value. (Thus, enumerations must skeletal MIB module might be assigned to consecutive bits;
however, see Section 9 constructed: e.g.,

FIZBIN-MIB DEFINITIONS ::= BEGIN

IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, experimental

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FROM SNMPv2-SMI;

fizbin MODULE-IDENTITY
LAST-UPDATED "199505241811Z"
ORGANIZATION "IETF SNMPv2 Working Group"
CONTACT-INFO
" Marshall T. Rose

Postal: Dover Beach Consulting, Inc.
420 Whisman Court
Mountain View, CA 94043-2186
US

Tel: +1 415 968 1052
Fax: +1 415 968 2510

E-mail: mrose@dbc.mtview.ca.us"

DESCRIPTION
"The MIB module for refinements entities implementing the xxxx
protocol."
REVISION "9505241811Z"
DESCRIPTION
"The latest version of an object with this syntax.)

As part MIB module."
REVISION "9210070433Z"
DESCRIPTION
"The initial version of updating an information this MIB module, published in
RFC yyyy."
-- contact IANA for actual number
::= { experimental xx }

END

6. Mapping of the OBJECT-IDENTITY macro

The OBJECT-IDENTITY macro is used to define information about an object
OBJECT IDENTIFIER assignment. All administrative OBJECT IDENTIFIER
assignments which define a type identification value (see
AutonomousType, a textual convention defined using in [3]) should be
defined via the BITS construct, new enumerations can OBJECT-IDENTITY macro. It should be added or existing
enumerations can have new labels assigned to them. After an enumeration noted that the
expansion of the OBJECT-IDENTITY macro is added, it might not be possible to distinguish between an something which
conceptually happens during implementation and not during run-time.

6.1. Mapping of the updated object for STATUS clause

The STATUS clause, which must be present, indicates whether this
definition is current or historic.

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The value "current" means that the new enumeration definition is
not asserted, current and an implementation of valid.
The value "obsolete" means the object prior to the addition.
Depending on definition is obsolete and should not
be implemented and/or can be removed if previously implemented.
While the circumstances, such value "deprecated" also indicates an ambiguity could either be
desirable or could obsolete definition,
it permits new/continued implementation in order to foster
interoperability with older/existing implementations.

6.2. Mapping of the DESCRIPTION clause

The DESCRIPTION clause, which must be undesirable. present, contains a textual
description of the object assignment.

6.3. Mapping of the REFERENCE clause

The means REFERENCE clause, which need not be present, contains a textual
cross-reference to avoid such some other document, either another information
module which defines a related assignment, or some other document
which provides additional information relevant to this definition.

6.4. Mapping of the OBJECT-IDENTITY value

The value of an ambiguity invocation of the OBJECT-IDENTITY macro is dependent on an OBJECT
IDENTIFIER.

6.5. Usage Example

Consider how an OBJECT IDENTIFIER assignment might be made: e.g.,

fizbin69 OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The authoritative identity of the encoding Fizbin 69 chipset."
::= { fizbinChipSets 1 }

7. Mapping of values on the wire; however, one

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possibility OBJECT-TYPE macro

The OBJECT-TYPE macro is used to define new enumerations starting at a type of managed object. It
should be noted that the next multiple expansion of eight bits. (Of course, this can also result in the enumerations no
longer being contiguous.)

Although there OBJECT-TYPE macro is no SMI-specified limitation on the number
something which conceptually happens during implementation and not
during run-time.

For leaf objects which are not columnar objects (i.e., not contained
within a conceptual table), instances of
enumerations (and therefore on the length of a value), except as may be
imposed object are identified by
appending a sub-identifier of zero to the limit on the length name of an OCTET STRING, MIB designers
should realize that there may be implementation and interoperability
limitations for sizes in excess of 128 bits.

Finally, a label for a named-number enumeration must consist object.
Otherwise, the INDEX clause of one or
more letters or digits, up the conceptual row object superior to
a maximum columnar object defines instance identification information.

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7.1. Mapping of 64 characters, and the
initial character SYNTAX clause

The SYNTAX clause, which must be a lower-case letter. (However, labels longer
than 32 characters are not recommended.) Note present, defines the abstract data
structure corresponding to that hyphens are not
allowed by this specification.

7.1.5. IpAddress object. The IpAddress type represents a 32-bit internet address. It is
represented as an OCTET STRING of length 4, in network byte-order.

Note that the IpAddress type is a tagged type for historical reasons.
Network addresses should data structure must be represented using an invocation
one of the
TEXTUAL-CONVENTION macro [3].

7.1.6. Counter32

The Counter32 type represents following: a non-negative integer which monotonically
increases until it reaches base type, the BITS construct, or a maximum value of 2^32-1 (4294967295
decimal), when it wraps around textual
convention. (SEQUENCE OF and starts increasing again from zero.

Counters have no SEQUENCE are also possible for
conceptual tables, see section 7.1.12). The base types are those
defined "initial" value, and thus, in the ObjectSyntax CHOICE. A textual convention is a single value
newly-defined type defined as a sub-type of a
Counter has (in general) no information content. Discontinuities in the
monotonically increasing value normally occur at re-initialization base type [3].

An extended subset of the management system, and at other times as specified in the
description full capabilities of an object-type using this ASN.1 type. If such other
times can occur, for example, the creation of an object instance at
times other than re-initialization, then a corresponding object should
be defined, with an (1988) sub-
typing is allowed, as appropriate SYNTAX clause, to indicate the last
discontinuity. Examples of appropriate SYNTAX clause include: TimeStamp
(a textual convention defined in [3]), DateAndTime (another textual
convention from [3]) underlying ASN.1 type. Any
such restriction on size, range or TimeTicks.

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The value of the MAX-ACCESS clause for objects with a SYNTAX enumerations specified in this
clause
value represents the maximal level of Counter32 is either "read-only" or "accessible-for-notify". support which makes "protocol
sense". Restrictions on sub-typing are specified in detail in
Section 9 and Appendix A DEFVAL clause is not allowed for objects with a SYNTAX clause value of
Counter32.

7.1.7. Gauge32 this memo.

The Gauge32 semantics of ObjectSyntax are now described.

7.1.1. Integer32 and INTEGER

The Integer32 type represents a non-negative integer, which integer-valued information between
-2^31 and 2^31-1 inclusive (-2147483648 to 2147483647 decimal). This
type is indistinguishable from the INTEGER type. Both the INTEGER
and Integer32 types may increase
or decrease, but shall never exceed a maximum value, nor fall below a
minimum value. The maximum value can not be greater sub-typed to be more constrained than 2^32-1
(4294967295 decimal), and the minimum value can
Integer32 type.

The INTEGER type (but not the Integer32 type) may also be smaller than 0.
The value of a Gauge32 has its maximum value whenever the used to
represent integer-valued information
being modeled as named-number enumerations.
In this case, only those named-numbers so enumerated may be present
as a value. Note that although it is greater than or equal to its maximum value, recommended that enumerated
values start at 1 and has its
minimum be numbered contiguously, any valid value whenever the information being modeled for
Integer32 is smaller than allowed for an enumerated value and, further, enumerated
values needn't be contiguously assigned.

Finally, a label for a named-number enumeration must consist of one
or
equal more letters or digits, up to its minimum value. If the information being modeled
subsequently decreases below (increases above) the a maximum (minimum)
value, the Gauge32 also decreases (increases). (Note that despite of
the use of 64 characters, and the term "latched" in the original definition of this type,
it does
initial character must be a lower-case letter. (However, labels
longer than 32 characters are not become "stuck" at its maximum or minimum value.)

7.1.8. TimeTicks recommended.) Note that hyphens
are not allowed by this specification (except for use by information
modules converted from SMIv1 which did allow hyphens).

7.1.2. OCTET STRING

The TimeTicks OCTET STRING type represents a non-negative integer which represents arbitrary binary or textual data.
Although the time, modulo 2^32 (4294967296 decimal), in hundredths of a second
between two epochs. When objects are defined which use SMI-specified size limitation for this ASN.1 type,
the description of the object identifies both of the reference epochs.

For example, [3] defines the TimeStamp textual convention which type is based
on the TimeTicks type. With a TimeStamp, the first reference epoch is
defined as the time when sysUpTime [5] was zero, 65535
octets, MIB designers should realize that there may be implementation
and the second
reference epoch is defined as the current value interoperability limitations for sizes in excess of sysUpTime. 255 octets.

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7.1.3. OBJECT IDENTIFIER

The TimeTicks OBJECT IDENTIFIER type represents administratively assigned
names. Any instance of this type may have at most 128 sub-
identifiers. Further, each sub-identifier must not be sub-typed.

7.1.9. Opaque exceed the value
2^32-1 (4294967295 decimal).

7.1.4. The Opaque type BITS construct

The BITS construct represents an enumeration of named bits. This
collection is provided solely for backward-compatibility, and shall
not assigned non-negative, contiguous (but see below)
values, starting at zero. Only those named-bits so enumerated may be used
present in a value. (Thus, enumerations must be assigned to
consecutive bits; however, see Section 9 for newly-defined refinements of an object types.

The Opaque type supports the capability to pass arbitrary ASN.1 syntax.
A value is encoded using the ASN.1 Basic Encoding Rules [4] into a

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Draft SMIv2 January 1999

string
with this syntax.)

As part of octets. This, in turn, is encoded as updating an OCTET STRING, in
effect "double-wrapping" information module, for an object defined
using the original ASN.1 value.

Note that a conforming implementation need only BITS construct, new enumerations can be able added or existing
enumerations can have new labels assigned to accept and
recognize opaquely-encoded data. It need them. After an
enumeration is added, it might not be able possible to unwrap distinguish between
an implementation of the data updated object for which the new enumeration
is not asserted, and then interpret its contents.

A requirement an implementation of the object prior to the
addition. Depending on "standard" MIB modules the circumstances, such an ambiguity could
either be desirable or could be undesirable. The means to avoid such
an ambiguity is that dependent on the encoding of values on the wire;
however, one possibility is to define new enumerations starting at
the next multiple of eight bits. (Of course, this can also result in
the enumerations no object longer being contiguous.)

Although there is no SMI-specified limitation on the number of
enumerations (and therefore on the length of a value), except as may have
be imposed by the limit on the length of an OCTET STRING, MIB
designers should realize that there may be implementation and
interoperability limitations for sizes in excess of 128 bits.

Finally, a
SYNTAX clause value label for a named-number enumeration must consist of Opaque.

7.1.10. Counter64 one
or more letters or digits, up to a maximum of 64 characters, and the
initial character must be a lower-case letter. (However, labels
longer than 32 characters are not recommended.) Note that hyphens
are not allowed by this specification.

7.1.5. IpAddress

The Counter64 IpAddress type represents a 32-bit internet address. It is
represented as an OCTET STRING of length 4, in network byte-order.

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Note that the IpAddress type is a tagged type for historical reasons.
Network addresses should be represented using an invocation of the
TEXTUAL-CONVENTION macro [3].

7.1.6. Counter32

The Counter32 type represents a non-negative integer which
monotonically increases until it reaches a maximum value of 2^64-1
(18446744073709551615 2^32-1
(4294967295 decimal), when it wraps around and starts increasing
again from zero.

Counters have no defined "initial" value, and thus, a single value of
a Counter has (in general) no information content. Discontinuities
in the monotonically increasing value normally occur at re-initialization re-
initialization of the management system, and at other times as
specified in the description of an object-type using this ASN.1 type.
If such other times can occur, for example, the creation of an object
instance at times other than re-initialization, then a corresponding
object should be defined, with an appropriate SYNTAX clause, to
indicate the last discontinuity. Examples of appropriate SYNTAX
clause are: include: TimeStamp (a textual convention defined in [3]),
DateAndTime (another textual convention from [3]) or TimeTicks.

The value of the MAX-ACCESS clause for objects with a SYNTAX clause
value of Counter64 Counter32 is either "read-only" or "accessible-for-notify".

A requirement on "standard" MIB modules is that the Counter64 type may
be used only if the information being modeled would wrap in less than
one hour if the Counter32 type was used instead.

A DEFVAL clause is not allowed for objects with a SYNTAX clause value
of
Counter64.

7.1.11. Unsigned32 Counter32.

7.1.7. Gauge32

The Unsigned32 Gauge32 type represents integer-valued information between 0 and
2^32-1 inclusive (0 to 4294967295 decimal).

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7.1.12. Conceptual Tables

Management operations apply exclusively to scalar objects. However, it
is sometimes convenient for developers of management applications to
impose an imaginary, tabular structure on an ordered collection of
objects within the MIB. Each such conceptual table contains zero or
more rows, and each row a non-negative integer, which may contain one
increase or more scalar objects, termed
columnar objects. This conceptualization is formalized by using the
OBJECT-TYPE macro to define both an object which corresponds to decrease, but shall never exceed a table maximum value, nor
fall below a minimum value. The maximum value can not be greater
than 2^32-1 (4294967295 decimal), and an object which corresponds to the minimum value can not be
smaller than 0. The value of a row in that table. A conceptual
table Gauge32 has SYNTAX of its maximum value
whenever the form:

SEQUENCE OF <EntryType>

where <EntryType> refers information being modeled is greater than or equal to the SEQUENCE type of
its subordinate
conceptual row. A conceptual row maximum value, and has SYNTAX of its minimum value whenever the form:

where <EntryType> information
being modeled is a SEQUENCE type defined as follows:

<EntryType> ::= SEQUENCE { <type1>, ... , <typeN> }

where there is one <type> for each subordinate object, and each <type>
is of smaller than or equal to its minimum value. If the form:

where <descriptor> is
information being modeled subsequently decreases below (increases
above) the descriptor naming a subordinate object, and
<syntax> has maximum (minimum) value, the value of that subordinate object's SYNTAX clause,
except Gauge32 also decreases
(increases). (Note that both sub-typing information and the named values for
enumerated integers or despite of the named bits for use of the BITS construct, are
omitted from <syntax>.

Further, a <type> is always present for every subordinate object. (The
ASN.1 DEFAULT and OPTIONAL clauses are disallowed term "latched" in
the SEQUENCE
definition.) The MAX-ACCESS clause for conceptual tables and rows is
"not-accessible".

7.1.12.1. Creation and Deletion original definition of Conceptual Rows

For newly-defined conceptual rows this type, it does not become "stuck" at
its maximum or minimum value.)

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7.1.8. TimeTicks

The TimeTicks type represents a non-negative integer which allow represents
the creation time, modulo 2^32 (4294967296 decimal), in hundredths of new object
instances and/or a second
between two epochs. When objects are defined which use this ASN.1
type, the deletion description of existing object instances, there should
be one columnar the object with a SYNTAX clause value identifies both of RowStatus (a

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Draft SMIv2 January 1999 the reference
epochs.

For example, [3] defines the TimeStamp textual convention defined in [3]) and a MAX-ACCESS clause value of
read-create. By convention, this which is termed
based on the status column for TimeTicks type. With a TimeStamp, the
conceptual row.

7.2. Mapping of first reference
epoch is defined as the UNITS clause

This UNITS clause, which need time when sysUpTime [5] was zero, and the
second reference epoch is defined as the current value of sysUpTime.

The TimeTicks type may not be present, contains sub-typed.

7.1.9. Opaque

The Opaque type is provided solely for backward-compatibility, and
shall not be used for newly-defined object types.

The Opaque type supports the capability to pass arbitrary ASN.1
syntax. A value is encoded using the ASN.1 Basic Encoding Rules [4]
into a textual
definition string of octets. This, in turn, is encoded as an OCTET
STRING, in effect "double-wrapping" the units associated with original ASN.1 value.

Note that object.

7.3. Mapping of a conforming implementation need only be able to accept and
recognize opaquely-encoded data. It need not be able to unwrap the MAX-ACCESS
data and then interpret its contents.

A requirement on "standard" MIB modules is that no object may have a
SYNTAX clause value of Opaque.

7.1.10. Counter64

The MAX-ACCESS clause, Counter64 type represents a non-negative integer which must be present, defines whether
monotonically increases until it makes
"protocol sense" to read, write and/or create an instance reaches a maximum value of 2^64-1
(18446744073709551615 decimal), when it wraps around and starts
increasing again from zero.

Counters have no defined "initial" value, and thus, a single value of
a Counter has (in general) no information content. Discontinuities
in the object,
or to include its monotonically increasing value normally occur at re-
initialization of the management system, and at other times as
specified in a notification. This is the maximal level description of
access an object-type using this ASN.1 type.
If such other times can occur, for example, the object. (This maximal level of access is independent creation of
any administrative authorization policy.)

The value "read-write" indicates that read and write access make
"protocol sense", but create does not. The value "read-create"
indicates that read, write and create access make "protocol sense". The
value "not-accessible" indicates an auxiliary object (see Section 7.7).
The value "accessible-for-notify" indicates an object which is
accessible only via a notification (e.g., snmpTrapOID [5]).

These values are ordered, from least to greatest: "not-accessible",
"accessible-for-notify", "read-only", "read-write", "read-create".

If any columnar object in a conceptual row has "read-create" as its
maximal level of access, then no
instance at times other columnar than re-initialization, then a corresponding
object of should be defined, with an appropriate SYNTAX clause, to
indicate the same
conceptual row may have a maximal access of "read-write". (Note that
"read-create" is a superset of "read-write".)

7.4. Mapping last discontinuity. Examples of the STATUS appropriate SYNTAX

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RFC 2578 SMIv2 April 1999

clause

The STATUS clause, which must be present, indicates whether this
definition is current are: TimeStamp (a textual convention defined in [3]),
DateAndTime (another textual convention from [3]) or historic. TimeTicks.

The value "current" means that of the definition is current and valid. The MAX-ACCESS clause for objects with a SYNTAX clause
value "obsolete" means the definition of Counter64 is obsolete and should not be
implemented and/or can either "read-only" or "accessible-for-notify".

A requirement on "standard" MIB modules is that the Counter64 type
may be removed used only if previously implemented. While the
value "deprecated" also indicates an obsolete definition, it permits
new/continued implementation information being modeled would wrap in order to foster interoperability with

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older/existing implementations.

7.5. Mapping of less
than one hour if the DESCRIPTION Counter32 type was used instead.

A DEFVAL clause

The DESCRIPTION clause, which must be present, contains a textual
definition of that object which provides all semantic definitions
necessary is not allowed for implementation, and should embody any information which
would otherwise be communicated in any ASN.1 commentary annotations
associated objects with the object.

7.6. Mapping of the REFERENCE a SYNTAX clause value
of Counter64.

7.1.11. Unsigned32

The REFERENCE clause, which need not be present, contains a textual
cross-reference to some other document, either another information
module which defines a related assignment, or some other document which
provides additional Unsigned32 type represents integer-valued information relevant between 0
and 2^32-1 inclusive (0 to this definition.

7.7. Mapping of the INDEX clause

The INDEX clause, which must be present if that object corresponds 4294967295 decimal).

7.1.12. Conceptual Tables

Management operations apply exclusively to a
conceptual row (unless an AUGMENTS clause scalar objects. However,
it is present instead), and must
be absent otherwise, defines instance identification information sometimes convenient for the
columnar objects subordinate developers of management applications
to that object.

The instance identification information in impose an INDEX clause must specify
object(s) such that value(s) imaginary, tabular structure on an ordered collection of those object(s) will unambiguously
distinguish a conceptual row. The objects can be columnar
objects from within the same and/or another MIB. Each such conceptual table, but must not be table contains zero or
more rows, and each row may contain one or more scalar objects,
termed columnar objects. Multiple occurrences of This conceptualization is formalized by
using the same object in OBJECT-TYPE macro to define both an object which
corresponds to a single INDEX
clause is strongly discouraged.

The syntax of the objects in the INDEX clause indicate how table and an object which corresponds to form the
instance-identifier:

(1) integer-valued (i.e., having INTEGER as its underlying primitive
type): a single sub-identifier taking the integer value (this works
only for non-negative integers);

(2) string-valued, fixed-length strings (or variable-length preceded by row in
that table. A conceptual table has SYNTAX of the IMPLIED keyword): `n' sub-identifiers, form:

SEQUENCE OF <EntryType>

where `n' is <EntryType> refers to the length SEQUENCE type of the string (each octet its subordinate
conceptual row. A conceptual row has SYNTAX of the string form:

where <EntryType> is encoded in a separate
sub-identifier);

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Draft SMIv2 January 1999

(3) string-valued, variable-length strings (not preceded by the IMPLIED
keyword): `n+1' sub-identifiers, SEQUENCE type defined as follows:

<EntryType> ::= SEQUENCE { <type1>, ... , <typeN> }

where `n' is the length of the
string (the first sub-identifier there is `n' itself, following this, one <type> for each octet of the string subordinate object, and each
<type> is encoded in a separate sub-identifier);

(4) object identifier-valued (when preceded by of the IMPLIED keyword):
`n' sub-identifiers, form:

where `n' <descriptor> is the number of sub-identifiers in descriptor naming a subordinate object, and
<syntax> has the value (each sub-identifier of that subordinate object's SYNTAX clause,

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RFC 2578 SMIv2 April 1999

except that both sub-typing information and the value is copied into a
separate sub-identifier);

(5) object identifier-valued (when not preceded by the IMPLIED
keyword): `n+1' sub-identifiers, where `n' is named values for
enumerated integers or the number of sub-
identifiers in named bits for the value (the first sub-identifier BITS construct, are
omitted from <syntax>.

Further, a <type> is `n' itself,
following this, each sub-identifier always present for every subordinate object.
(The ASN.1 DEFAULT and OPTIONAL clauses are disallowed in the value
SEQUENCE definition.) The MAX-ACCESS clause for conceptual tables
and rows is copied);

(6) IpAddress-valued: 4 sub-identifiers, in the familiar a.b.c.d
notation.

Note that "not-accessible".

7.1.12.1. Creation and Deletion of Conceptual Rows

For newly-defined conceptual rows which allow the IMPLIED keyword can only be present for an object having a
variable-length syntax (e.g., variable-length strings or creation of new
object
identifier-valued objects), Further, the IMPLIED keyword can only be
associated with instances and/or the last deletion of existing object in the INDEX clause. Finally, the
IMPLIED keyword may not instances,
there should be used on a variable-length string one columnar object if
that string might have with a SYNTAX clause value of zero-length.

Since
RowStatus (a textual convention defined in [3]) and a single MAX-ACCESS
clause value of read-create. By convention, this is termed the
status column for the conceptual row.

7.2. Mapping of the UNITS clause

This UNITS clause, which need not be present, contains a Counter has (in general) no information
content (see section 7.1.6 and 7.1.10), objects defined using textual
definition of the
syntax, Counter32 or Counter64, units associated with that object.

7.3. Mapping of the MAX-ACCESS clause

The MAX-ACCESS clause, which must not be specified in an INDEX
clause. If present, defines whether it
makes "protocol sense" to read, write and/or create an object defined using instance of
the BITS construct is used object, or to include its value in an
INDEX clause, it is considered a variable-length string.

Instances identified by use notification. This is the
maximal level of integer-valued objects should be numbered
starting from one (i.e., not from zero). The use access for the object. (This maximal level of zero as a
access is independent of any administrative authorization policy.)

The value for "read-write" indicates that read and write access make
"protocol sense", but create does not. The value "read-create"
indicates that read, write and create access make "protocol sense".
The value "not-accessible" indicates an auxiliary object (see Section
7.7). The value "accessible-for-notify" indicates an integer-valued index object should be avoided, except in special
cases.

Objects which is
accessible only via a notification (e.g., snmpTrapOID [5]).

These values are both specified ordered, from least to greatest: "not-accessible",
"accessible-for-notify", "read-only", "read-write", "read-create".

If any columnar object in the INDEX clause of a conceptual row
and also has "read-create" as its
maximal level of access, then no other columnar objects object of the same
conceptual row are termed
auxiliary objects. The MAX-ACCESS clause for auxiliary objects may have a maximal access of "read-write". (Note that
"read-create" is
"not-accessible", except in the following circumstances:

(1) within a MIB module originally written to conform to SMIv1, and
later converted to conform to SMIv2; or

Expires July 1999 superset of "read-write".)

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RFC 2578 SMIv2 January April 1999

(2) a conceptual row must contain at least one columnar object which is
not an auxiliary object. In the event that all

7.4. Mapping of a conceptual
row's columnar objects are also specified in its INDEX the STATUS clause

The STATUS clause, then
one of them which must be accessible, i.e., have a MAX-ACCESS clause of
"read-only". (Note that present, indicates whether this situation does not arise for a
conceptual row allowing create access, since such a row will have a
status column which will
definition is current or historic.

The value "current" means that the definition is current and valid.
The value "obsolete" means the definition is obsolete and should not
be implemented and/or can be removed if previously implemented.
While the value "deprecated" also indicates an auxiliary object.)

Note that objects specified obsolete definition,
it permits new/continued implementation in a conceptual row's INDEX clause need not
be columnar objects order to foster
interoperability with older/existing implementations.

7.5. Mapping of that conceptual row. In this situation, the DESCRIPTION clause of the conceptual row

The DESCRIPTION clause, which must include be present, contains a textual
explanation of how the objects which are included in the INDEX clause
but not columnar objects
definition of that conceptual row, are used object which provides all semantic definitions
necessary for implementation, and should embody any information which
would otherwise be communicated in uniquely
identifying instances of any ASN.1 commentary annotations
associated with the conceptual row's columnar objects.

7.8. object.

7.6. Mapping of the AUGMENTS REFERENCE clause

The AUGMENTS REFERENCE clause, which must need not be present unless the object
corresponds present, contains a textual
cross-reference to some other document, either another information
module which defines a conceptual row, is an alternative related assignment, or some other document
which provides additional information relevant to this definition.

7.7. Mapping of the INDEX clause.
Every object corresponding to a conceptual row has either an INDEX clause or an AUGMENTS clause.

If an

The INDEX clause, which must be present if that object corresponding corresponds to
a conceptual row has (unless an INDEX clause, that
row AUGMENTS clause is termed a base conceptual row; alternatively, if the object has an
AUGMENTS clause, the row is said to present instead), and
must be a conceptual row augmentation,
where the AUGMENTS clause names the object corresponding to absent otherwise, defines instance identification information
for the base
conceptual row which is augmented by this conceptual row augmentation.
(Thus, a conceptual row augmentation cannot itself be augmented.)
Instances of subordinate columnar objects of a conceptual row
augmentation are identified according subordinate to the that object.

The instance identification information in an INDEX clause must
specify object(s) such that value(s) of the base
conceptual row corresponding to the object named in the AUGMENTS clause.
Further, instances of subordinate columnar objects of those object(s) will
unambiguously distinguish a conceptual row
augmentation exist according to the same semantics as instances of
subordinate row. The objects can be
columnar objects of from the base same and/or another conceptual row being augmented.
As such, note that creation table, but
must not be scalar objects. Multiple occurrences of a base conceptual row implies the
correspondent creation of any conceptual row augmentations.

For example, a MIB designer might wish to define additional columns in
an "enterprise-specific" MIB which logically extend a conceptual row same object
in a "standard" MIB. single INDEX clause is strongly discouraged.

The "standard" MIB definition syntax of the conceptual row
would include objects in the INDEX clause and the "enterprise-specific" MIB would
contain indicate how to form
the definition of instance-identifier:

(1) integer-valued (i.e., having INTEGER as its underlying primitive
type): a conceptual row using the AUGMENTS clause.
On the other hand, it would be incorrect to use single sub-identifier taking the AUGMENTS clause integer value (this
works only for
the relationship between RFC 2233's ifTable and the many media-specific

Expires July 1999 non-negative integers);

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MIBs which extend it for specific media (e.g.,

(2) string-valued, fixed-length strings (or variable-length preceded by
the dot3Table in RFC
2358), since not all interfaces are IMPLIED keyword): `n' sub-identifiers, where `n' is the length
of the same media.

Note that string (each octet of the string is encoded in a base conceptual row may be augmented separate
sub-identifier);

(3) string-valued, variable-length strings (not preceded by multiple conceptual
row augmentations.

7.8.1. Relation between INDEX and AUGMENTS clauses

When defining instance identification information for a conceptual
table:

(1) If there the IMPLIED
keyword): `n+1' sub-identifiers, where `n' is a one-to-one correspondence between the conceptual rows length of this table and an existing table, then the AUGMENTS clause
should be used.

(2) Otherwise, if there
string (the first sub-identifier is a sparse relationship between the conceptual
rows `n' itself, following this,
each octet of this table and an existing table, then an INDEX clause
should be used which the string is identical to that encoded in the existing table.
For example, the relationship between RFC 2233's ifTable and a
media-specific MIB which extends separate sub-identifier);

(4) object identifier-valued (when preceded by the ifTable for a specific media
(e.g., IMPLIED keyword):
`n' sub-identifiers, where `n' is the dot3Table number of sub-identifiers in RFC 2358),
the value (each sub-identifier of the value is copied into a sparse relationship.

(3) Otherwise, if no existing objects have
separate sub-identifier);

(5) object identifier-valued (when not preceded by the required syntax and
semantics, then auxiliary objects should be defined within IMPLIED
keyword): `n+1' sub-identifiers, where `n' is the
conceptual row for the new table, and those objects should be used
within the INDEX clause for the conceptual row.

7.9. Mapping number of sub-
identifiers in the DEFVAL clause

The DEFVAL clause, which need not be present, defines an acceptable
default value which may be used at the discretion of an agent when an
object instance (the first sub-identifier is created. That is, `n' itself,
following this, each sub-identifier in the value is a "hint" to
implementors.

During conceptual row creation, if copied);

(6) IpAddress-valued: 4 sub-identifiers, in the familiar a.b.c.d
notation.

Note that the IMPLIED keyword can only be present for an instance of object
having a columnar variable-length syntax (e.g., variable-length strings or
object is
not present as one of identifier-valued objects), Further, the operands in IMPLIED keyword can
only be associated with the correspondent management
protocol set operation, then last object in the value of INDEX clause.
Finally, the DEFVAL clause, IMPLIED keyword may not be used on a variable-length
string object if present,
indicates an acceptable default value that an agent string might use
(especially for have a read-only object).

Note that with this definition value of zero-length.

Since a single value of a Counter has (in general) no information
content (see section 7.1.6 and 7.1.10), objects defined using the DEFVAL
syntax, Counter32 or Counter64, must not be specified in an INDEX

clause. If an object defined using the BITS construct is used in an
INDEX clause, it is appropriate
to use it for any columnar object of considered a read-create table. It is also
permitted to variable-length string.

Instances identified by use it for scalar objects dynamically created by an agent,

Expires July 1999 [Page 35]

Draft SMIv2 January 1999

or for columnar of integer-valued objects should be
numbered starting from one (i.e., not from zero). The use of zero as
a read-write table dynamically created by an
agent.

The value of for an integer-valued index object should be avoided, except
in special cases.

Objects which are both specified in the DEFVAL INDEX clause must, of course, correspond to a conceptual
row and also columnar objects of the SYNTAX same conceptual row are termed
auxiliary objects. The MAX-ACCESS clause for auxiliary objects is
"not-accessible", except in the object. If the value following circumstances:

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RFC 2578 SMIv2 April 1999

(1) within a MIB module originally written to conform to SMIv1, and
later converted to conform to SMIv2; or

(2) a conceptual row must contain at least one columnar object which is
not an OBJECT IDENTIFIER, auxiliary object. In the event that all of a conceptual
row's columnar objects are also specified in its INDEX clause, then it
one of them must be expressed as a single ASN.1 identifier, and not as accessible, i.e., have a collection MAX-ACCESS clause of sub-identifiers.

Note
"read-only". (Note that if an operand to the management protocol set operation is an
instance of this situation does not arise for a read-only object, then the error `notWritable' [6]
conceptual row allowing create access, since such a row will have a
status column which will not be
returned. As such, the DEFVAL an auxiliary object.)

Note that objects specified in a conceptual row's INDEX clause can need
not be used to provide an
acceptable default value columnar objects of that an agent might use.

By way conceptual row. In this situation,
the DESCRIPTION clause of example, consider the following possible DEFVAL clauses:

ObjectSyntax DEFVAL clause
---------------- ------------
Integer32 DEFVAL { 1 }
-- same for Gauge32, TimeTicks, Unsigned32
INTEGER DEFVAL { valid } -- enumerated value
OCTET STRING DEFVAL { 'ffffffffffff'H }
DisplayString DEFVAL { "SNMP agent" }
IpAddress DEFVAL { 'c0210415'H } -- 192.33.4.21
OBJECT IDENTIFIER DEFVAL { sysDescr }
BITS DEFVAL { { primary, secondary } }
-- enumerated values that are set
BITS DEFVAL { { } }
-- no enumerated values are set

A binary string used in a DEFVAL clause for an OCTET STRING conceptual row must be
either an integral multiple of eight or zero bits in length; similarly, include a hexadecimal string must be an even number of hexadecimal digits. The
value textual
explanation of a character string used how the objects which are included in a DEFVAL the INDEX clause must
but not contain tab
characters or line terminator characters.

Object types with SYNTAX columnar objects of Counter32 and Counter64 may not have DEFVAL
clauses, since they do not have defined initial values. However, it is
recommended that they be initialized to zero.

7.10. Mapping of the OBJECT-TYPE value

The value of an invocation conceptual row, are used in uniquely
identifying instances of the OBJECT-TYPE macro is the name conceptual row's columnar objects.

7.8. Mapping of the
object, AUGMENTS clause

The AUGMENTS clause, which is an OBJECT IDENTIFIER, an administratively assigned
name.

Expires July 1999 [Page 36]

Draft SMIv2 January 1999

When an OBJECT IDENTIFIER is assigned to an object:

(1) If must not be present unless the object
corresponds to a conceptual table, then only a single
assignment, that for a conceptual row, is present immediately
beneath that object. The administratively assigned name for an alternative to the INDEX
clause. Every object corresponding to a conceptual row has either an
INDEX clause or an AUGMENTS clause.

If an object corresponding to a conceptual row has an INDEX clause,
that row is derived by appending termed a sub-identifier of
"1" to the administratively assigned name for the base conceptual table.

(2) If row; alternatively, if the
object corresponds has an AUGMENTS clause, the row is said to be a conceptual row, then at least one
assignment, one for each column in row
augmentation, where the AUGMENTS clause names the object
corresponding to the base conceptual row, is present
beneath that object. The administratively assigned name for each
column row which is derived augmented by appending this
conceptual row augmentation. (Thus, a unique, positive sub-identifier conceptual row augmentation
cannot itself be augmented.) Instances of subordinate columnar
objects of a conceptual row augmentation are identified according to
the administratively assigned name for INDEX clause of the base conceptual row.

(3) Otherwise, no other OBJECT IDENTIFIERs which are subordinate row corresponding to the
object may be assigned.

Note that named in the final sub-identifier AUGMENTS clause. Further, instances of
subordinate columnar objects of any administratively assigned name
for an object shall be positive. A zero-valued final sub-identifier is
reserved for future use.

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7.11. Usage Example

Consider how one might define a conceptual table and its subordinates.
(This example uses row augmentation exist
according to the RowStatus textual convention defined in [3].)

evalSlot OBJECT-TYPE
SYNTAX Integer32 (0..2147483647)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The index number same semantics as instances of the first unassigned entry in the
evaluation table, or the value subordinate columnar
objects of zero indicating that all
entries are assigned.

A management station should create new entries in the
evaluation table using this algorithm: first, issue base conceptual row being augmented. As such, note
that creation of a
management protocol retrieval operation to determine base conceptual row implies the
value correspondent
creation of evalSlot; and, second, issue any conceptual row augmentations.

For example, a management protocol
set operation MIB designer might wish to create define additional columns
in an instance "enterprise-specific" MIB which logically extend a conceptual
row in a "standard" MIB. The "standard" MIB definition of the evalStatus object
setting its value to createAndGo(4) or createAndWait(5). If
this latter operation succeeds, then
conceptual row would include the management station
may continue modifying INDEX clause and the instances corresponding to "enterprise-
specific" MIB would contain the
newly created conceptual row, without fear definition of collision with a conceptual row using
the AUGMENTS clause. On the other management stations."
::= { eval 1 }

evalTable OBJECT-TYPE
SYNTAX SEQUENCE OF EvalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) evaluation table."
::= { eval 2 }

evalEntry OBJECT-TYPE
SYNTAX EvalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in hand, it would be incorrect to use
the evaluation table."
INDEX { evalIndex }
::= { evalTable 1 }

EvalEntry ::=
SEQUENCE {

Expires July 1999 AUGMENTS clause for the relationship between RFC 2233's ifTable

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evalIndex Integer32,
evalString DisplayString,
evalValue Integer32,
evalStatus RowStatus
}

evalIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The auxiliary variable used

and the many media-specific MIBs which extend it for identifying instances of specific media
(e.g., the columnar objects dot3Table in the evaluation table."
::= { evalEntry 1 }

evalString OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The string to evaluate."
::= { evalEntry 2 }

evalValue OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value when evalString was last evaluated, or zero if no
such value is available."
DEFVAL { 0 }
::= { evalEntry 3 }

evalStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status column used for creating, modifying, and
deleting instances RFC 2358), since not all interfaces are of
the columnar objects in same media.

Note that a base conceptual row may be augmented by multiple
conceptual row augmentations.

7.8.1. Relation between INDEX and AUGMENTS clauses

When defining instance identification information for a conceptual
table:

(1) If there is a one-to-one correspondence between the evaluation
table."
DEFVAL { active }
::= { evalEntry 4 }

Expires July 1999 [Page 39]

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8. Mapping conceptual rows
of this table and an existing table, then the NOTIFICATION-TYPE macro

The NOTIFICATION-TYPE macro AUGMENTS clause
should be used.

(2) Otherwise, if there is used to define a sparse relationship between the information contained
within an unsolicited transmission conceptual
rows of management information (i.e.,
within either a SNMPv2-Trap-PDU or InformRequest-PDU). It this table and an existing table, then an INDEX clause
should be
noted used which is identical to that in the expansion of existing table.
For example, the NOTIFICATION-TYPE macro is something
which conceptually happens during implementation relationship between RFC 2233's ifTable and not during run-
time.

8.1. Mapping of the OBJECTS clause

The OBJECTS clause, which need not be present, defines an ordered
sequence of a
media-specific MIB object types. One and only one object instance for each
occurrence of each object type must be present, and in the specified
order, in every instance of which extends the notification. If ifTable for a specific media
(e.g., the same object type
occurs multiple times dot3Table in RFC 2358), is a notification's ordered sequence, sparse relationship.

(3) Otherwise, if no existing objects have the required syntax and
semantics, then an
object instance is present auxiliary objects should be defined within the
conceptual row for each of them. An object type specified
in this clause must not have an MAX-ACCESS clause of "not-accessible".
The notification's DESCRIPTION the new table, and those objects should be used
within the INDEX clause must specify for the
information/meaning conveyed by each occurrence conceptual row.

7.9. Mapping of each object type in the sequence. The DESCRIPTION DEFVAL clause must also specify

The DEFVAL clause, which need not be present, defines an acceptable
default value which may be used at the discretion of an agent when an
object instance is present for each object type in created. That is, the notification.

Note that an agent value is allowed, at its own discretion, a "hint" to append as many
additional objects
implementors.

During conceptual row creation, if an instance of a columnar object
is not present as it considers useful to the end one of the notification
(i.e., after operands in the objects defined by correspondent management
protocol set operation, then the OBJECTS clause).

8.2. Mapping value of the STATUS clause

The STATUS DEFVAL clause, which must be if
present, indicates whether an acceptable default value that an agent might
use (especially for a read-only object).

Note that with this definition of the DEFVAL clause, it is current or historic.

The value "current" means that the definition is current and valid. The
value "obsolete" means the definition
appropriate to use it for any columnar object of a read-create table.
It is obsolete and should not be
implemented and/or can be removed if previously implemented. While the
value "deprecated" also indicates an obsolete definition, it permits
new/continued implementation in order permitted to foster interoperability with
older/existing implementations.

Expires July 1999 use it for scalar objects dynamically created
by an agent, or for columnar objects of a read-write table
dynamically created by an agent.

McCloghrie, et al. Standards Track [Page 40]

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8.3. Mapping

The value of the DESCRIPTION DEFVAL clause

The DESCRIPTION clause, which must be present, contains a textual
definition must, of course, correspond to the notification which provides all semantic definitions
necessary
SYNTAX clause for implementation, and should embody any information which
would otherwise the object. If the value is an OBJECT IDENTIFIER,
then it must be communicated in any expressed as a single ASN.1 commentary annotations
associated with the notification. In particular, identifier, and not as a
collection of sub-identifiers.

Note that if an operand to the DESCRIPTION clause
should document which instances management protocol set operation is
an instance of a read-only object, then the objects mentioned in error `notWritable' [6]
will be returned. As such, the OBJECTS DEFVAL clause should can be contained within notifications of this type.

8.4. Mapping used to provide
an acceptable default value that an agent might use.

By way of example, consider the REFERENCE following possible DEFVAL clauses:

ObjectSyntax DEFVAL clause

The REFERENCE clause, which need not be present, contains a textual
cross-reference to some other document, either another information
module which defines
---------------- ------------
Integer32 DEFVAL { 1 }
-- same for Gauge32, TimeTicks, Unsigned32
INTEGER DEFVAL { valid } -- enumerated value
OCTET STRING DEFVAL { 'ffffffffffff'H }
DisplayString DEFVAL { "SNMP agent" }
IpAddress DEFVAL { 'c0210415'H } -- 192.33.4.21
OBJECT IDENTIFIER DEFVAL { sysDescr }
BITS DEFVAL { { primary, secondary } }
-- enumerated values that are set
BITS DEFVAL { { } }
-- no enumerated values are set

A binary string used in a related assignment, DEFVAL clause for an OCTET STRING must be
either an integral multiple of eight or some other document which
provides additional information relevant zero bits in length;
similarly, a hexadecimal string must be an even number of hexadecimal
digits. The value of a character string used in a DEFVAL clause must
not contain tab characters or line terminator characters.

Object types with SYNTAX of Counter32 and Counter64 may not have
DEFVAL clauses, since they do not have defined initial values.
However, it is recommended that they be initialized to this definition.

8.5. zero.

7.10. Mapping of the NOTIFICATION-TYPE OBJECT-TYPE value

The value of an invocation of the NOTIFICATION-TYPE OBJECT-TYPE macro is the name of
the notification, object, which is an OBJECT IDENTIFIER, an administratively
assigned name. In order

When an OBJECT IDENTIFIER is assigned to achieve compatibility with SNMPv1 traps,
both when converting SMIv1 information modules to/from this SMI, and in
the procedures employed by multi-lingual systems and proxy forwarding
applications, an object:

(1) If the next object corresponds to last sub-identifier in the a conceptual table, then only a single
assignment, that for a conceptual row, is present immediately
beneath that object. The administratively assigned name of any newly-
defined notification must have for the value zero.

Sections 4.2.6 and 4.2.7 of [6] describe how the NOTIFICATION-TYPE macro
conceptual row object is used to generate derived by appending a SNMPv2-Trap-PDU or InformRequest-PDU,
respectively.

Expires July 1999 sub-identifier of

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8.6.

"1" to the administratively assigned name for the conceptual table.

(2) If the object corresponds to a conceptual row, then at least one
assignment, one for each column in the conceptual row, is present
beneath that object. The administratively assigned name for each
column is derived by appending a unique, positive sub-identifier to
the administratively assigned name for the conceptual row.

(3) Otherwise, no other OBJECT IDENTIFIERs which are subordinate to the
object may be assigned.

Note that the final sub-identifier of any administratively assigned
name for an object shall be positive. A zero-valued final sub-
identifier is reserved for future use.

7.11. Usage Example

Consider how a configuration change notification one might be described:

entityMIBTraps OBJECT IDENTIFIER ::= { entityMIB 2 }
entityMIBTrapPrefix OBJECT IDENTIFIER ::= { entityMIBTraps 0 }

entConfigChange NOTIFICATION-TYPE define a conceptual table and its
subordinates. (This example uses the RowStatus textual convention
defined in [3].)

evalSlot OBJECT-TYPE
SYNTAX Integer32 (0..2147483647)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An entConfigChange trap is sent when
"The index number of the first unassigned entry in the
evaluation table, or the value of
entLastChangeTime changes. It can be utilized by an NMS to
trigger logical/physical entity table maintenance polls.

An agent must not generate more than one entConfigChange
'trap-event' zero indicating that
all entries are assigned.

A management station should create new entries in a five second period, where a 'trap-event'
is the transmission of
evaluation table using this algorithm: first, issue a single trap PDU
management protocol retrieval operation to a list of trap
destinations. If additional configuration changes occur
within the five second 'throttling' period, then these
trap-events should be suppressed by the agent. An NMS should
periodically check determine the
value of entLastChangeTime evalSlot; and, second, issue a management
protocol set operation to detect
any missed entConfigChange trap-events, e.g. due create an instance of the
evalStatus object setting its value to
throttling createAndGo(4) or transmission loss."
::= { entityMIBTrapPrefix 1 }

According to
createAndWait(5). If this invocation, latter operation succeeds,
then the notification authoritatively
identified as management station may continue modifying the
instances corresponding to the newly created conceptual
row, without fear of collision with other management
stations."
::= { entityMIBTrapPrefix eval 1 }

is used to report a particular type of configuration change.

Expires July 1999

evalTable OBJECT-TYPE
SYNTAX SEQUENCE OF EvalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION

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9. Refined Syntax

Some macros have clauses which allows syntax to be refined,
specifically: the

"The (conceptual) evaluation table."
::= { eval 2 }

evalEntry OBJECT-TYPE
SYNTAX clause of EvalEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the evaluation table."
INDEX { evalIndex }
::= { evalTable 1 }

EvalEntry ::=
SEQUENCE {
evalIndex Integer32,
evalString DisplayString,
evalValue Integer32,
evalStatus RowStatus
}

evalIndex OBJECT-TYPE macro, and the
SYNTAX/WRITE-SYNTAX clauses
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The auxiliary variable used for identifying instances of
the MODULE-COMPLIANCE and AGENT-
CAPABILITIES macros [2]. However, not all refinements of syntax are
appropriate. In particular, columnar objects in the object's primitive or application type
must not be changed.

Further, the following restrictions apply:

Restrictions evaluation table."
::= { evalEntry 1 }

evalString OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The string to Refinement of
object syntax range enumeration size
----------------- ----- ----------- ----
INTEGER (1) (2) - evaluate."
::= { evalEntry 2 }

evalValue OBJECT-TYPE
SYNTAX Integer32 (1) - -
Unsigned32 (1) - -
OCTET STRING - - (3)
OBJECT IDENTIFIER - - -
BITS - (2) -
IpAddress - - -
Counter32 - - -
Counter64 - - -
Gauge32 (1) - -
TimeTicks - - -

where:

(1) the range
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value when evalString was last evaluated, or zero if
no such value is available."
DEFVAL { 0 }
::= { evalEntry 3 }

evalStatus OBJECT-TYPE

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RFC 2578 SMIv2 April 1999

SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status column used for creating, modifying, and
deleting instances of permitted values may be refined by raising the lower-
bounds, by reducing the upper-bounds, and/or by reducing the
alternative value/range choices;

(2) columnar objects in the enumeration
evaluation table."
DEFVAL { active }
::= { evalEntry 4 }

8. Mapping of named-values may be refined by removing one or
more named-values (note that for BITS, a refinement may cause the
enumerations NOTIFICATION-TYPE macro

The NOTIFICATION-TYPE macro is used to no longer be contiguous); or,

(3) define the size in octets information
contained within an unsolicited transmission of the value may management
information (i.e., within either a SNMPv2-Trap-PDU or InformRequest-
PDU). It should be refined by raising noted that the
lower-bounds, by reducing expansion of the upper-bounds, and/or by reducing the
alternative size choices.

No other types NOTIFICATION-TYPE
macro is something which conceptually happens during implementation
and not during run-time.

8.1. Mapping of refinements can be specified in the SYNTAX clause.
However, the DESCRIPTION OBJECTS clause is available to specify additional
restrictions

The OBJECTS clause, which can need not be expressed present, defines an ordered
sequence of MIB object types. One and only one object instance for
each occurrence of each object type must be present, and in the SYNTAX clause. Further
details on (and examples of) sub-typing are provided
specified order, in Appendix A.

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10. Extending every instance of the notification. If the same
object type occurs multiple times in a notification's ordered
sequence, then an Information Module

As experience object instance is gained with an information module, it may be desirable
to revise that information module. However, changes are present for each of them. An
object type specified in this clause must not allowed if
they have any potential to cause interoperability problems "over the
wire" between an implementation using an original specification and an
implementation using an updated specification(s).

For any change, the invocation MAX-ACCESS
clause of the MODULE-IDENTITY macro "not-accessible". The notification's DESCRIPTION clause
must be
updated to include information about the revision: specifically,
updating specify the LAST-UPDATED clause, adding a pair information/meaning conveyed by each occurrence of REVISION and
each object type in the sequence. The DESCRIPTION clauses (see section 5.5), and making any necessary changes
to existing clauses, including clause must also
specify which object instance is present for each object type in the ORGANIZATION and CONTACT-INFO
clauses.
notification.

Note that any definition contained in an information module agent is available allowed, at its own discretion, to append as
many additional objects as it considers useful to be IMPORT-ed by any other information module, and is referenced in an
IMPORTS clause via the module name. Thus, a module name should not be
changed. Specifically, end of the module name (e.g., "FIZBIN-MIB" in
notification (i.e., after the
example objects defined by the OBJECTS clause).

8.2. Mapping of Section 5.7) should not the STATUS clause

The STATUS clause, which must be changed when revising an
information module (except to correct typographical errors), present, indicates whether this
definition is current or historic.

The value "current" means that the definition is current and valid.
The value "obsolete" means the definition is obsolete and
definitions should not
be moved from one information module to another.

Also note that obsolete definitions must not implemented and/or can be removed from MIB modules
since their descriptors may still be referenced by other information
modules, and if previously implemented.
While the OBJECT IDENTIFIERs used to name them must never be re-
assigned.

10.1. Object Assignments

If any non-editorial change is made value "deprecated" also indicates an obsolete definition,
it permits new/continued implementation in order to any clause foster

McCloghrie, et al. Standards Track [Page 34]

RFC 2578 SMIv2 April 1999

interoperability with older/existing implementations.

8.3. Mapping of a object
assignment, then the OBJECT IDENTIFIER value associated with that object
assignment DESCRIPTION clause

The DESCRIPTION clause, which must also be changed, along with its associated descriptor.

10.2. Object Definitions

An object present, contains a textual
definition may be revised in any of the following ways:

(1) A SYNTAX clause containing an enumerated INTEGER may have new
enumerations added or existing labels changed. Similarly, named
bits may be added or existing labels changed notification which provides all semantic
definitions necessary for the BITS
construct.

Expires July 1999 [Page 44]

Draft SMIv2 January 1999

(2) The value of a SYNTAX clause may implementation, and should embody any
information which would otherwise be replaced by a textual
convention, providing the textual convention is defined to use the
same primitive communicated in any ASN.1 type, has
commentary annotations associated with the same set of values, and has
identical semantics.

(3) A STATUS clause value of "current" may be revised as "deprecated"
or "obsolete". Similarly, a STATUS clause value of "deprecated"
may be revised as "obsolete". When making such a change, notification. In
particular, the DESCRIPTION clause should be updated to explain document which instances of
the rationale.

(4) A DEFVAL objects mentioned in the OBJECTS clause may should be added or updated.

(5) A contained
within notifications of this type.

8.4. Mapping of the REFERENCE clause may

The REFERENCE clause, which need not be added present, contains a textual
cross-reference to some other document, either another information
module which defines a related assignment, or updated.

(6) A UNITS clause may be added.

(7) A conceptual row may be augmented by adding new columnar objects at some other document
which provides additional information relevant to this definition.

8.5. Mapping of the end NOTIFICATION-TYPE value

The value of an invocation of the row, and making NOTIFICATION-TYPE macro is the corresponding update to name
of the
SEQUENCE definition.

(8) Clarifications and additional notification, which is an OBJECT IDENTIFIER, an
administratively assigned name. In order to achieve compatibility
with SNMPv1 traps, both when converting SMIv1 information may be included modules
to/from this SMI, and in the
DESCRIPTION clause.

(9) Entirely new objects may be defined, named with previously
unassigned OBJECT IDENTIFIER values.

Otherwise, if procedures employed by multi-lingual
systems and proxy forwarding applications, the semantics of any previously defined object are changed
(i.e., if a non-editorial change is made next to last sub-
identifier in the name of any clause other than those
specifically allowed above), then newly-defined notification must have
the OBJECT IDENTIFIER value associated
with that object must also be changed.

Note that changing zero.

Sections 4.2.6 and 4.2.7 of [6] describe how the descriptor associated with an existing object NOTIFICATION-TYPE
macro is
considered a semantic change, as these strings may be used in an IMPORTS
statement.

10.3. Notification Definitions

A notification definition may be revised in any of the following ways:

(1) A REFERENCE clause may be added or updated.

(2) A STATUS clause value of "current" may be revised as "deprecated" to generate a SNMPv2-Trap-PDU or "obsolete". Similarly, InformRequest-PDU,
respectively.

8.6. Usage Example

Consider how a configuration change notification might be described:

entityMIBTraps OBJECT IDENTIFIER ::= { entityMIB 2 }
entityMIBTrapPrefix OBJECT IDENTIFIER ::= { entityMIBTraps 0 }

entConfigChange NOTIFICATION-TYPE
STATUS clause current
DESCRIPTION
"An entConfigChange trap is sent when the value of "deprecated"
may
entLastChangeTime changes. It can be revised as "obsolete". When making such a change, the

Expires July 1999 utilized by an NMS to
trigger logical/physical entity table maintenance polls.

McCloghrie, et al. Standards Track [Page 45]

Draft 35]

RFC 2578 SMIv2 January April 1999

DESCRIPTION clause should be updated to explain

An agent must not generate more than one entConfigChange
'trap-event' in a five second period, where a 'trap-event'
is the rationale.

(3) A DESCRIPTION clause may be clarified.

Otherwise, if the semantics transmission of any previously defined notification are
changed (i.e., if a non-editorial change is made single trap PDU to any clause other
those specifically allowed above), a list of
trap destinations. If additional configuration changes
occur within the five second 'throttling' period, then
these trap-events should be suppressed by the agent. An
NMS should periodically check the OBJECT IDENTIFIER value
associated with that notification must also be changed.

Note that changing of
entLastChangeTime to detect any missed entConfigChange
trap-events, e.g. due to throttling or transmission loss."
::= { entityMIBTrapPrefix 1 }

According to this invocation, the descriptor associated with an existing notification is considered a semantic change, authoritatively
identified as these strings may be

{ entityMIBTrapPrefix 1 }

is used in an IMPORTS statement.

Expires July 1999 [Page 46]

Draft SMIv2 January 1999

11. Appendix A: Detailed Sub-typing Rules

11.1. to report a particular type of configuration change.

9. Refined Syntax Rules

The syntax rules for sub-typing are given below. Note that while this

Some macros have clauses which allows syntax is based on ASN.1, it includes some extensions beyond what is
allowed in ASN.1, to be refined,
specifically: the SYNTAX clause of the OBJECT-TYPE macro, and a number the
SYNTAX/WRITE-SYNTAX clauses of ASN.1 constructs the MODULE-COMPLIANCE and AGENT-
CAPABILITIES macros [2]. However, not all refinements of syntax are
appropriate. In particular, the object's primitive or application
type must not allowed by
this syntax.

<integerSubType>
::= <empty>
| "(" <range> ["|" <range>]... ")"

<octetStringSubType>
::= <empty>
| "(" "SIZE" "(" <range> ["|" <range>]... ")" ")"

where:
<empty> is be changed.

Further, the empty string
<number> is a non-negative integer
<hexString> is a hexadecimal string (e.g., 'xxxx'H)
<binString> is a binary string (e.g, 'xxxx'B)

<range> is further restricted as follows: following restrictions apply:

Restrictions to Refinement of
object syntax range enumeration size
----------------- ----- ----------- ----
INTEGER (1) (2) - any <value> used in a SIZE clause must be non-negative.
Integer32 (1) - when a pair -
Unsigned32 (1) - -
OCTET STRING - - (3)
OBJECT IDENTIFIER - - -
BITS - (2) -
IpAddress - - -
Counter32 - - -
Counter64 - - -
Gauge32 (1) - -
TimeTicks - - -

where:

McCloghrie, et al. Standards Track [Page 36]

RFC 2578 SMIv2 April 1999

(1) the range of permitted values is specified, the first value
must may be less than refined by raising the second value.
- when multiple ranges are specified, lower-
bounds, by reducing the ranges upper-bounds, and/or by reducing the
alternative value/range choices;

(2) the enumeration of named-values may
not overlap but be refined by removing one or
more named-values (note that for BITS, a refinement may touch. For example, (1..4 | 4..9)
is invalid, and (1..4 | 5..9) is valid.
- cause the ranges must
enumerations to no longer be a subset of contiguous); or,

(3) the maximum range size in octets of the
base type.

Expires July 1999 [Page 47]

Draft SMIv2 January 1999

11.2. Examples

Some examples value may be refined by raising the
lower-bounds, by reducing the upper-bounds, and/or by reducing the
alternative size choices.

No other types of legal sub-typing:

Integer32 (-20..100)
Integer32 (0..100 | 300..500)
Integer32 (300..500 | 0..100)
Integer32 (0 | 2 | 4 | 6 | 8 | 10)
OCTET STRING (SIZE(0..100))
OCTET STRING (SIZE(0..100 | 300..500))
OCTET STRING (SIZE(0 | 2 | 4 | 6 | 8 | 10))
SYNTAX TimeInterval (0..100) refinements can be specified in the SYNTAX DisplayString (SIZE(0..32))

(Note clause.
However, the last two examples above are DESCRIPTION clause is available to specify additional
restrictions which can not valid be expressed in a TEXTUAL CONVENTION,
see [3].)

Some the SYNTAX clause.
Further details on (and examples of illegal sub-typing:

10. Extending an Information Module

As experience is gained with an information module, it may be
desirable to revise that information module. However, changes are
not allowed
Integer32 (SIZE (0..34)) -- must not use SIZE
OCTET STRING (0..100) -- must use SIZE
OCTET STRING (SIZE(-10..100)) -- negative SIZE

Expires July 1999 [Page 48]

Draft SMIv2 January 1999

12. Security Considerations

This document defines a language with which if they have any potential to write cause interoperability
problems "over the wire" between an implementation using an original
specification and read
descriptions an implementation using an updated
specification(s).

For any change, the invocation of management information. The language itself has no
security impact on the Internet.

13. Editors' Addresses

Keith McCloghrie
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
USA
Phone: +1 408 526 5260
Email: kzm@cisco.com

David Perkins
Desktalk Systems & SNMPinfo
3763 Benton Street
Santa Clara, CA 95051
USA
Phone: +1 408 221-8702
Email: dperkins@snmpinfo.com

Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3283
Email: schoenw@ibr.cs.tu-bs.de

Expires July 1999 [Page 49]

Draft SMIv2 January 1999

14. References

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

[2] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M.,
and Waldbusser, S. "Conformance Statements for SMIv2", draft-ops-
smiv2-conf-01.txt, January 1999.

[3] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M.,
and Waldbusser, S. "Textual Conventions for SMIv2", draft-ops-
smiv2-tc-01.txt, January 1999.

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

[5] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
Waldbusser, S., "Management Information Base for Version 2 of MODULE-IDENTITY macro must be
updated to include information about the
Simple Network Management Protocol (SNMPv2)", RFC 1907, January
1996.

[6] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
Waldbusser, S., "Protocol Operations for Version 2 of revision: specifically,
updating the Simple
Network Management Protocol (SNMPv2)", RFC 1905, January 1996.

Expires July 1999 [Page 50]

Draft SMIv2 January 1999

15. Full Copyright Statement

This document and translations LAST-UPDATED clause, adding a pair of it may be copied REVISION and furnished
DESCRIPTION clauses (see section 5.5), and making any necessary
changes to
others, existing clauses, including the ORGANIZATION and derivative works CONTACT-
INFO clauses.

Note that comment on or otherwise explain it or
assist any definition contained in its implementation may be prepared, copied, published an information module is
available to be IMPORT-ed by any other information module, and
distributed, in whole or is
referenced in part, without restriction of any kind,
provided that an IMPORTS clause via the above copyright notice and this paragraph are included
on all such copies and derivative works. However, this document itself
may module name. Thus, a module
name should 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 changed. Specifically, the procedures for copyrights defined module name (e.g.,
"FIZBIN-MIB" in the Internet
Standards process must example of Section 5.7) should not be followed, or as required changed
when revising an information module (except to translate it into
languages other than English.

The limited permissions granted above are perpetual correct typographical
errors), and will definitions should not be
revoked moved from one information
module to another.

Also note that obsolete definitions must not be removed from MIB
modules since their descriptors may still be referenced by the Internet Society or its successors or assigns.

This document and the other
information contained herein is provided on an "AS
IS" basis modules, 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."

Expires July 1999 the OBJECT IDENTIFIERs used to name them
must never be re-assigned.

McCloghrie, et al. Standards Track [Page 51]

Draft 37]

RFC 2578 SMIv2 January April 1999

Table of Contents

1 Introduction .................................................... 2
1.1 A Note on Terminology ......................................... 2
2 Definitions ..................................................... 3
3.1 The MODULE-IDENTITY macro ..................................... 4
3.2

10.1. Object Names and Syntaxes ..................................... 7
3.3 The OBJECT-TYPE macro ......................................... 10
3.5 The NOTIFICATION-TYPE macro ................................... 12
3.6 Administrative Identifiers .................................... 12
3 Information Modules ............................................. 13
3.1 Macro Invocation .............................................. 14
3.1.1 Textual Values and Strings .................................. 15
3.2 IMPORTing Symbols ............................................. 15
3.3 Exporting Symbols ............................................. 16
3.4 ASN.1 Comments ................................................ 16
3.5 OBJECT IDENTIFIER values ...................................... 16
3.6 OBJECT IDENTIFIER usage ....................................... 17
3.7 Reserved Keywords ............................................. 18
4 Naming Hierarchy ................................................ 19
5 Mapping of the MODULE-IDENTITY macro ............................ 20
5.1 Mapping of the LAST-UPDATED Assignments

If any non-editorial change is made to any clause ............................ 20
5.2 Mapping of a object
assignment, then the ORGANIZATION clause ............................ 20
5.3 Mapping OBJECT IDENTIFIER value associated with that
object assignment must also be changed, along with its associated
descriptor.

10.2. Object Definitions

An object definition may be revised in any of the CONTACT-INFO following ways:

(1) A SYNTAX clause ............................ 20
5.4 Mapping of containing an enumerated INTEGER may have new
enumerations added or existing labels changed. Similarly, named
bits may be added or existing labels changed for the DESCRIPTION clause ............................. 20
5.5 Mapping BITS
construct.

(2) The value of the REVISION a SYNTAX clause ................................ 20
5.5.1 Mapping of may be replaced by a textual
convention, providing the DESCRIPTION sub-clause ....................... 21
5.6 Mapping of textual convention is defined to use the MODULE-IDENTITY value .......................... 21
5.7 Usage Example ................................................. 22
6 Mapping of
same primitive ASN.1 type, has the OBJECT-IDENTITY macro ............................ 23
6.1 Mapping same set of the values, and has
identical semantics.

(3) A STATUS clause .................................. 23
6.2 Mapping value of the DESCRIPTION "current" may be revised as "deprecated"
or "obsolete". Similarly, a STATUS clause ............................. 23
6.3 Mapping value of the REFERENCE clause ............................... 23
6.4 Mapping "deprecated"
may be revised as "obsolete". When making such a change, the
DESCRIPTION clause should be updated to explain the rationale.

(4) A DEFVAL clause may be added or updated.

(5) A REFERENCE clause may be added or updated.

(6) A UNITS clause may be added.

(7) A conceptual row may be augmented by adding new columnar objects at
the end of the row, and making the corresponding update to the
SEQUENCE definition.

(8) Clarifications and additional information may be included in the
DESCRIPTION clause.

(9) Entirely new objects may be defined, named with previously
unassigned OBJECT IDENTIFIER values.

Otherwise, if the semantics of any previously defined object are
changed (i.e., if a non-editorial change is made to any clause other
than those specifically allowed above), then the OBJECT IDENTIFIER
value associated with that object must also be changed.

McCloghrie, et al. Standards Track [Page 38]

RFC 2578 SMIv2 April 1999

Note that changing the descriptor associated with an existing object
is considered a semantic change, as these strings may be used in an
IMPORTS statement.

10.3. Notification Definitions

A notification definition may be revised in any of the following
ways:

(1) A REFERENCE clause may be added or updated.

(2) A STATUS clause value of "current" may be revised as "deprecated"
or "obsolete". Similarly, a STATUS clause value of "deprecated"
may be revised as "obsolete". When making such a change, the
DESCRIPTION clause should be updated to explain the rationale.

(3) A DESCRIPTION clause may be clarified.

Otherwise, if the semantics of any previously defined notification
are changed (i.e., if a non-editorial change is made to any clause
other those specifically allowed above), then the OBJECT IDENTIFIER
value associated with that notification must also be changed.

Note that changing the descriptor associated with an existing
notification is considered a semantic change, as these strings may be
used in an IMPORTS statement.

McCloghrie, et al. Standards Track [Page 39]

RFC 2578 SMIv2 April 1999

11. Appendix A: Detailed Sub-typing Rules

11.1. Syntax Rules

The syntax rules for sub-typing are given below. Note that while
this syntax is based on ASN.1, it includes some extensions beyond
what is allowed in ASN.1, and a number of ASN.1 constructs are not
allowed by this syntax.

<integerSubType>
::= <empty>
| "(" <range> ["|" <range>]... ")"

<octetStringSubType>
::= <empty>
| "(" "SIZE" "(" <range> ["|" <range>]... ")" ")"

where:
<empty> is the empty string
<number> is a non-negative integer
<hexString> is a hexadecimal string (e.g., '0F0F'H)
<binString> is a binary string (e.g, '1010'B)

<range> is further restricted as follows:
- any <value> used in a SIZE clause must be non-negative.
- when a pair of values is specified, the first value
must be less than the second value.
- when multiple ranges are specified, the ranges may
not overlap but may touch. For example, (1..4 | 4..9)
is invalid, and (1..4 | 5..9) is valid.
- the ranges must be a subset of the maximum range of the
base type.

McCloghrie, et al. Standards Track [Page 40]

RFC 2578 SMIv2 April 1999

11.2. Examples

Some examples of legal sub-typing:

(Note the last two examples above are not valid in a TEXTUAL
CONVENTION, see [3].)

Some examples of illegal sub-typing:

Integer32 (150..100) -- first greater than second
Integer32 (0..100 | 50..500) -- ranges overlap
Integer32 (0 | 2 | 0 ) -- value duplicated
Integer32 (MIN..-1 | 1..MAX) -- MIN and MAX not allowed
Integer32 (SIZE (0..34)) -- must not use SIZE
OCTET STRING (0..100) -- must use SIZE
OCTET STRING (SIZE(-10..100)) -- negative SIZE

12. Security Considerations

This document defines a language with which to write and read
descriptions of management information. The language itself has no
security impact on the Internet.

13. Editors' Addresses

Keith McCloghrie
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
USA
Phone: +1 408 526 5260
EMail: kzm@cisco.com

McCloghrie, et al. Standards Track [Page 41]

RFC 2578 SMIv2 April 1999

David Perkins
SNMPinfo
3763 Benton Street
Santa Clara, CA 95051
USA
Phone: +1 408 221-8702
EMail: dperkins@snmpinfo.com

Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3283
EMail: schoenw@ibr.cs.tu-bs.de

14. References

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

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

[4] Information processing systems - Open Systems Interconnection -
Specification of the OBJECT-IDENTITY value .......................... 23
6.5 Usage Example ................................................. 24
7 Mapping Basic Encoding Rules for Abstract Syntax Notation
One (ASN.1), International Organization for Standardization.
International Standard 8825, (December, 1987).

[5] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and
S. Waldbusser, "Management Information Base for Version 2 of the OBJECT-TYPE macro ................................ 25
7.1 Mapping
Simple Network Management Protocol (SNMPv2)", RFC 1907, January
1996.

[6] The SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and
S. Waldbusser, "Protocol Operations for Version 2 of the SYNTAX clause .................................. 25
7.1.1 Integer32 and INTEGER ....................................... 25
7.1.2 OCTET STRING ................................................ 26
7.1.3 OBJECT IDENTIFIER ........................................... 26
7.1.4 The BITS construct .......................................... 26
7.1.5 IpAddress ................................................... 27
7.1.6 Counter32 ................................................... 27
7.1.7 Gauge32 ..................................................... 28

Expires July 1999 Simple
Network Management Protocol (SNMPv2)", RFC 1905, January 1996.

McCloghrie, et al. Standards Track [Page 52]

Draft 42]

RFC 2578 SMIv2 January April 1999

7.1.8 TimeTicks ................................................... 28
7.1.9 Opaque ...................................................... 28
7.1.10 Counter64 .................................................. 29
7.1.11 Unsigned32 ................................................. 29
7.1.12 Conceptual Tables .......................................... 30
7.1.12.1 Creation

15. Full Copyright Statement

This document and Deletion of Conceptual Rows ................. 30
7.2 Mapping of the UNITS clause ................................... 31
7.3 Mapping of the MAX-ACCESS clause .............................. 31
7.4 Mapping of the STATUS clause .................................. 31
7.5 Mapping of the DESCRIPTION clause ............................. 32
7.6 Mapping of the REFERENCE clause ............................... 32
7.7 Mapping of the INDEX clause ................................... 32
7.8 Mapping translations of the AUGMENTS clause ................................ 34
7.8.1 Relation between INDEX 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 AUGMENTS clauses ................. 35
7.9 Mapping distributed, in whole or in part, without restriction of any
kind, provided that the DEFVAL clause .................................. 35
7.10 Mapping of 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 OBJECT-TYPE value ............................. 36
7.11 Usage Example ................................................ 38
8 Mapping of copyright notice or references to the NOTIFICATION-TYPE macro .......................... 40
8.1 Mapping of Internet Society or other
Internet organizations, except as needed for the OBJECTS clause ................................. 40
8.2 Mapping purpose of
developing Internet standards in which case the STATUS clause .................................. 40
8.3 Mapping of procedures for
copyrights defined in the DESCRIPTION clause ............................. 41
8.4 Mapping of 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 REFERENCE clause ............................... 41
8.5 Mapping of Internet Society or its successors or assigns.

This document and the NOTIFICATION-TYPE value ........................ 41
8.6 Usage Example ................................................. 42
9 Refined Syntax .................................................. 43
10 Extending information contained herein is provided on an Information Module ................................ 44
10.1 Object Assignments ........................................... 44
10.2 Object Definitions ........................................... 44
10.3 Notification Definitions ..................................... 45
11 Appendix A: Detailed Sub-typing Rules .......................... 47
11.1 Syntax Rules ................................................. 47
11.2 Examples ..................................................... 48
12 Security Considerations ........................................ 49
13 Editors' Addresses ............................................. 49
14 References ..................................................... 50
15 Full Copyright Statement ....................................... 51

Expires July 1999
"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."

McCloghrie, et al. Standards Track [Page 53] 43]

----