draft-ietf-snmpv2-smi-ds-01.txt   draft-ietf-snmpv2-smi-ds-02.txt 
Structure of Management Information Structure of Management Information
for Version 2 of the for Version 2 of the
Simple Network Management Protocol (SNMPv2) Simple Network Management Protocol (SNMPv2)
19 March 1995 | 31 May 1995 |
draft-ietf-snmpv2-smi-ds-01.txt | draft-ietf-snmpv2-smi-ds-02.txt |
Jeffrey D. Case Jeffrey D. Case
SNMP Research, Inc. SNMP Research, Inc.
case@snmp.com case@snmp.com
Keith McCloghrie Keith McCloghrie
Cisco Systems, Inc. Cisco Systems, Inc.
kzm@cisco.com kzm@cisco.com
Marshall T. Rose Marshall T. Rose
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authorization, access control, and privacy policies. authorization, access control, and privacy policies.
Management stations execute management applications which monitor and Management stations execute management applications which monitor and
control managed elements. Managed elements are devices such as hosts, control managed elements. Managed elements are devices such as hosts,
routers, terminal servers, etc., which are monitored and controlled via routers, terminal servers, etc., which are monitored and controlled via
access to their management information. access to their management information.
Management information is viewed as a collection of managed objects, Management information is viewed as a collection of managed objects,
residing in a virtual information store, termed the Management residing in a virtual information store, termed the Management
Information Base (MIB). Collections of related objects are defined in Information Base (MIB). Collections of related objects are defined in
MIB modules. These modules are written using a subset of OSI's Abstract MIB modules. These modules are written using an adapted subset of OSI's |
Syntax Notation One (ASN.1) [1]. It is the purpose of this document, Abstract Syntax |
the Structure of Management Information (SMI), to define that subset. Notation One (ASN.1) [1]. It is the purpose of this document, the
Structure of Management Information (SMI), to define that adapted |
subset, and to assign a set of associated administrative values. |
The SMI is divided into three parts: module definitions, object The SMI is divided into three parts: module definitions, object |
definitions, and, trap definitions. definitions, and, notification definitions. |
(1) Module definitions are used when describing information modules. (1) Module definitions are used when describing information modules.
An ASN.1 macro, MODULE-IDENTITY, is used to concisely convey the An ASN.1 macro, MODULE-IDENTITY, is used to concisely convey the
semantics of an information module. semantics of an information module.
(2) Object definitions are used when describing managed objects. An (2) Object definitions are used when describing managed objects. An
ASN.1 macro, OBJECT-TYPE, is used to concisely convey the syntax ASN.1 macro, OBJECT-TYPE, is used to concisely convey the syntax
and semantics of a managed object. and semantics of a managed object.
(3) Notification definitions are used when describing unsolicited (3) Notification definitions are used when describing unsolicited
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(3) Notification definitions are used when describing unsolicited (3) Notification definitions are used when describing unsolicited
transmissions of management information. An ASN.1 macro, transmissions of management information. An ASN.1 macro,
NOTIFICATION-TYPE, is used to concisely convey the syntax and NOTIFICATION-TYPE, is used to concisely convey the syntax and
semantics of a notification. semantics of a notification.
1.1. A Note on Terminology 1.1. A Note on Terminology
For the purpose of exposition, the original Internet-standard Network For the purpose of exposition, the original Internet-standard Network
Management Framework, as described in RFCs 1155, 1157, and 1212, is Management Framework, as described in RFCs 1155, 1157, and 1212, is
termed the SNMP version 1 framework (SNMPv1). The current framework is termed the SNMP version 1 framework (SNMPv1). The current framework is
termed the SNMP version 2 framework (SNMPv2). termed the SNMP version 2 framework (SNMPv2).
1.2. Change Log 2. Definitions -
For the 19 March version: +
- The changes adopted by the SNMPv2 Working Group. +
For the 1 November version:
- recast RFC 1442 into an Internet-Draft,
- fixed typos
- referred sub-typing restrictions to Section 9,
- stated explicitly the restrictions on enumeration labels,
- -
included the restriction on sub-typing of TimeTicks in section
7.1.8,
- added a rule for the use of IMPLIED with oid-valued INDEX
variables,
- clarified the circumstances under which auxiliary variables do not
have a MAX-ACCESS clause of "not-accessible",
- clarified the description of conceptual row augmentations, and
added examples,
- explicitly specified the macros in which refined syntax can be
used,
- included OID definitions for mib-2 and transmission.
2. Definitions
SNMPv2-SMI DEFINITIONS ::= BEGIN SNMPv2-SMI DEFINITIONS ::= BEGIN
-- the path to the root -- the path to the root
org OBJECT IDENTIFIER ::= { iso 3 } org OBJECT IDENTIFIER ::= { iso 3 }
dod OBJECT IDENTIFIER ::= { org 6 } dod OBJECT IDENTIFIER ::= { org 6 }
internet OBJECT IDENTIFIER ::= { dod 1 } internet OBJECT IDENTIFIER ::= { dod 1 }
directory OBJECT IDENTIFIER ::= { internet 1 } directory OBJECT IDENTIFIER ::= { internet 1 }
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TYPE NOTATION ::= TYPE NOTATION ::=
"STATUS" Status "STATUS" Status
"DESCRIPTION" Text "DESCRIPTION" Text
ReferPart ReferPart
VALUE NOTATION ::= VALUE NOTATION ::=
value(VALUE OBJECT IDENTIFIER) value(VALUE OBJECT IDENTIFIER)
Status ::= Status ::=
"current" "current"
| "deprecated" + | "deprecated"
| "obsolete" | "obsolete"
ReferPart ::= ReferPart ::=
"REFERENCE" Text "REFERENCE" Text
| empty | empty
Text ::= """" string """" Text ::= """" string """"
END END
-- names of objects -- names of objects
ObjectName ::= ObjectName ::=
OBJECT IDENTIFIER OBJECT IDENTIFIER
NotificationName ::= + NotificationName ::=
OBJECT IDENTIFIER + OBJECT IDENTIFIER
-- syntax of objects -- syntax of objects
ObjectSyntax ::= ObjectSyntax ::=
CHOICE { CHOICE {
simple simple
SimpleSyntax, SimpleSyntax,
-- note that SEQUENCEs for conceptual tables and -- note that SEQUENCEs for conceptual tables and
-- rows are not mentioned here... -- rows are not mentioned here...
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-- built-in ASN.1 types -- built-in ASN.1 types
SimpleSyntax ::= SimpleSyntax ::=
CHOICE { CHOICE {
-- INTEGERs with a more restrictive range -- INTEGERs with a more restrictive range
-- may also be used -- may also be used
integer-value -- includes Integer32 integer-value -- includes Integer32
INTEGER (-2147483648..2147483647), INTEGER (-2147483648..2147483647),
-- OCTET STRINGs with a more restrictive size + -- OCTET STRINGs with a more restrictive size
-- may also be used + -- may also be used
string-value string-value
OCTET STRING (SIZE (0..65535)), | OCTET STRING (SIZE (0..65535)),
objectID-value objectID-value
OBJECT IDENTIFIER | OBJECT IDENTIFIER
} }
-- indistinguishable from INTEGER, but never needs more than -- indistinguishable from INTEGER, but never needs more than
-- 32-bits for a two's complement representation -- 32-bits for a two's complement representation
Integer32 ::= Integer32 ::=
[UNIVERSAL 2] [UNIVERSAL 2]
IMPLICIT INTEGER (-2147483648..2147483647) IMPLICIT INTEGER (-2147483648..2147483647)
-- application-wide types -- application-wide types
ApplicationSyntax ::= ApplicationSyntax ::=
CHOICE { CHOICE {
ipAddress-value ipAddress-value
IpAddress, IpAddress,
counter-value counter-value
Counter32, Counter32,
gauge-value timeticks-value -
Gauge32,
timeticks-value
TimeTicks, TimeTicks,
arbitrary-value arbitrary-value
Opaque, Opaque,
nsapAddress-value big-counter-value -
NsapAddress,
big-counter-value
Counter64, Counter64,
old-unsigned-integer-value + old-unsigned-integer-value
UInteger32, + UInteger32,
unsigned-integer-value unsigned-integer-value -- includes Gauge32 |
Unsigned32 | Unsigned32
} }
-- in network-byte order -- in network-byte order
-- (this is a tagged type for historical reasons) -- (this is a tagged type for historical reasons)
IpAddress ::= IpAddress ::=
[APPLICATION 0] [APPLICATION 0]
IMPLICIT OCTET STRING (SIZE (4)) IMPLICIT OCTET STRING (SIZE (4))
-- this wraps -- this wraps
Counter32 ::= Counter32 ::=
[APPLICATION 1] [APPLICATION 1]
IMPLICIT INTEGER (0..4294967295) IMPLICIT INTEGER (0..4294967295)
-- this doesn't wrap -- this doesn't wrap
Gauge32 ::= Gauge32 ::=
[APPLICATION 2] [APPLICATION 2]
IMPLICIT INTEGER (0..4294967295) IMPLICIT INTEGER (0..4294967295)
Unsigned32 ::= + -- an unsigned 32-bit quantity
[APPLICATION 2] + -- indistinguishable from Gauge32
IMPLICIT INTEGER (0..4294967295) + Unsigned32 ::=
[APPLICATION 2]
IMPLICIT INTEGER (0..4294967295)
-- hundredths of seconds since an epoch -- hundredths of seconds since an epoch
TimeTicks ::= TimeTicks ::=
[APPLICATION 3] [APPLICATION 3]
IMPLICIT INTEGER (0..4294967295) IMPLICIT INTEGER (0..4294967295)
-- for backward-compatibility only -- for backward-compatibility only
Opaque ::= Opaque ::=
[APPLICATION 4] [APPLICATION 4]
IMPLICIT OCTET STRING IMPLICIT OCTET STRING
NsapAddress ::= -- for counters that wrap in less than one hour with only 32 bits -
[APPLICATION 5]
IMPLICIT OCTET STRING (SIZE (1 | 4..21))
Counter64 ::= Counter64 ::=
[APPLICATION 6] [APPLICATION 6]
IMPLICIT INTEGER (0..18446744073709551615) IMPLICIT INTEGER (0..18446744073709551615)
-- for backward-compatibility only
UInteger32 ::= UInteger32 ::=
[APPLICATION 7] [APPLICATION 7]
IMPLICIT INTEGER (0..4294967295) IMPLICIT INTEGER (0..4294967295)
-- definition for objects -- definition for objects
OBJECT-TYPE MACRO ::= OBJECT-TYPE MACRO ::=
BEGIN BEGIN
TYPE NOTATION ::= TYPE NOTATION ::=
"SYNTAX" Syntax | "SYNTAX" Syntax |
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"MAX-ACCESS" Access "MAX-ACCESS" Access
"STATUS" Status "STATUS" Status
"DESCRIPTION" Text "DESCRIPTION" Text
ReferPart ReferPart
IndexPart IndexPart
DefValPart DefValPart
VALUE NOTATION ::= VALUE NOTATION ::=
value(VALUE ObjectName) value(VALUE ObjectName)
Syntax ::= + Syntax ::=
type(ObjectSyntax) + type(ObjectSyntax)
| "BITS" "{" Kibbles "}" + | "BITS" "{" Kibbles "}" |
Kibbles ::= + Kibbles ::=
Kibble + Kibble
| Kibbles "," Kibble + | Kibbles "," Kibble |
Kibble ::= + Kibble ::=
identifier "(" nonNegativeNumber ")" + identifier "(" nonNegativeNumber ")"
UnitsPart ::= UnitsPart ::=
"UNITS" Text "UNITS" Text
| empty | empty
Access ::= Access ::=
"not-accessible" "not-accessible"
| "accessible-for-notify" + | "accessible-for-notify"
| "read-only" | "read-only"
| "read-write" | "read-write"
| "read-create" | "read-create"
Status ::= Status ::=
"current" "current"
| "deprecated" | "deprecated"
| "obsolete" | "obsolete"
ReferPart ::= ReferPart ::=
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NOTIFICATION-TYPE MACRO ::= NOTIFICATION-TYPE MACRO ::=
BEGIN BEGIN
TYPE NOTATION ::= TYPE NOTATION ::=
ObjectsPart ObjectsPart
"STATUS" Status "STATUS" Status
"DESCRIPTION" Text "DESCRIPTION" Text
ReferPart ReferPart
VALUE NOTATION ::= VALUE NOTATION ::=
value(VALUE NotificationName) | value(VALUE NotificationName)
ObjectsPart ::= ObjectsPart ::=
"OBJECTS" "{" Objects "}" "OBJECTS" "{" Objects "}"
| empty | empty
Objects ::= Objects ::=
Object Object
| Objects "," Object | Objects "," Object
Object ::= Object ::=
value(Name ObjectName) value(Name ObjectName)
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| "obsolete" | "obsolete"
ReferPart ::= ReferPart ::=
"REFERENCE" Text "REFERENCE" Text
| empty | empty
-- uses the NVT ASCII character set -- uses the NVT ASCII character set
Text ::= """" string """" Text ::= """" string """"
END END
-- definitions of administrative identifiers
zeroDotZero OBJECT-IDENTITY + zeroDotZero OBJECT-IDENTITY
STATUS current + STATUS current
DESCRIPTION + DESCRIPTION
"A value used for null identifiers." + "A value used for null identifiers."
::= { 0 0 } + ::= { 0 0 }
END END
3. Information Modules 3. Information Modules
An "information module" is an ASN.1 module defining information relating An "information module" is an ASN.1 module defining information relating
to network management. to network management.
The SMI describes how to use a subset of ASN.1 to define an information The SMI describes how to use a subset of ASN.1 to define an information
module. Further, additional restrictions are placed on "standard" module. Further, additional restrictions are placed on "standard"
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(1) MIB modules, which contain definitions of inter-related managed (1) MIB modules, which contain definitions of inter-related managed
objects, make use of the OBJECT-TYPE and NOTIFICATION-TYPE macros; objects, make use of the OBJECT-TYPE and NOTIFICATION-TYPE macros;
(2) compliance statements for MIB modules, which make use of the (2) compliance statements for MIB modules, which make use of the
MODULE-COMPLIANCE and OBJECT-GROUP macros [2]; and, MODULE-COMPLIANCE and OBJECT-GROUP macros [2]; and,
(3) capability statements for agent implementations which make use of (3) capability statements for agent implementations which make use of
the AGENT-CAPABILITIES macros [2]. the AGENT-CAPABILITIES macros [2].
This classification scheme does not imply a rigid taxonomy. For This classification scheme does not imply a rigid taxonomy. For
example, a "standard" information module might include definitions of example, a "standard" information module will normally include |
definitions of |
managed objects and a compliance statement. Similarly, an "enterprise- managed objects and a compliance statement. Similarly, an "enterprise-
specific" information module might include definitions of managed specific" information module might include definitions of managed
objects and a capability statement. Of course, a "standard" information objects and a capability statement. Of course, a "standard" information
module may not contain capability statements. module may not contain capability statements.
The constructs of ASN.1 allowed in SNMPv2 information modules include: +
the IMPORTS clause, value definitions for OBJECT IDENTIFIERs, type +
definitions for SEQUENCEs (with restrictions), ASN.1 type assignments of +
the restricted ASN.1 types allowed in SNMPv2, and instances of ASN.1 +
macros defined in this document and in other documents [2, 3] of the +
SNMPv2 framework. Additional ASN.1 macros may not be defined in SNMPv2 +
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 encouraged to +
choose names for their information modules that will have a low +
probability of colliding with standard or other enterprise information +
modules. An information module may not use the ASN.1 construct of +
placing an object identifier value between the module name and the +
"DEFINITIONS" keyword. +
All information modules start with exactly one invocation of the All information modules start with exactly one invocation of the
MODULE-IDENTITY macro, which provides contact and revision history. | MODULE-IDENTITY macro, which provides contact information as well as |
This invocation must appear immediately after any IMPORTs | revision history to distinguish between versions of the same information |
statements. module. |
This invocation must appear immediately after any IMPORTs statements.
3.1. Macro Invocation 3.1. Macro Invocation
Within an information module, each macro invocation appears as: Within an information module, each macro invocation appears as:
<descriptor> <macro> <clauses> ::= <value> <descriptor> <macro> <clauses> ::= <value>
where <descriptor> corresponds to an ASN.1 identifier, <macro> names the where <descriptor> corresponds to an ASN.1 identifier, <macro> names the
macro being invoked, and <clauses> and <value> depend on the definition macro being invoked, and <clauses> and <value> depend on the definition
of the macro. (Note that this definition of a descriptor applies to all + of the macro. (Note that this definition of a descriptor applies to all
macros defined in this memo and in [9].) + macros defined in this memo and in [2].) |
For the purposes of this specification, an ASN.1 identifier consists of | 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 | one or more letters or digits, and its initial character must be a
lower-case letter. (Note that hyphens are not allowed by this | lower-case letter. (Note that hyphens are not allowed by this
specification, even though hyphen is allowed by [1]. This restriction | specification, even though hyphen is allowed by [1]. This restriction
enables arithmetic expressions in languages which use the minus sign to | enables arithmetic expressions in languages which use the minus sign to
reference these descriptors without ambiguity.) | reference these descriptors without ambiguity.)
For all descriptors appearing in an information module, the descriptor For all descriptors appearing in an information module, the descriptor
shall be unique and mnemonic, and shall not exceed 64 characters in shall be unique and mnemonic, and shall not exceed 64 characters in
length. This promotes a common language for humans to use when length. (However, descriptors longer than 32 characters are not +
discussing the information module and also facilitates simple table recommended.) +
mappings for user-interfaces. This promotes a common language for humans to use when discussing the
information module and also facilitates simple table mappings for user-
interfaces.
The set of descriptors defined in all "standard" information modules The set of descriptors defined in all "standard" information modules
shall be unique. - shall be unique.
Finally, by convention, if the descriptor refers to an object with a Finally, by convention, if the descriptor refers to an object with a
SYNTAX clause value of either Counter32 or Counter64, then the SYNTAX clause value of either Counter32 or Counter64, then the
descriptor used for the object should denote plurality. descriptor used for the object should denote plurality.
3.1.1. Textual Clauses 3.1.1. Textual Clauses
Some clauses in a macro invocation may take a textual value (e.g., the Some clauses in a macro invocation may take a textual value (e.g., the
DESCRIPTION clause). Note that, in order to conform to the ASN.1 DESCRIPTION clause). Note that, in order to conform to the ASN.1
syntax, the entire value of these clauses must be enclosed in double syntax, the entire value of these clauses must be enclosed in double
quotation marks, and therefore cannot itself contain double quotation quotation marks, and therefore cannot itself contain double quotation
marks, although the value may be multi-line. marks, although the value may be multi-line.
3.2. IMPORTing Symbols 3.2. IMPORTing Symbols
To reference an external object, the IMPORTS statement must be used to To reference an external object, the IMPORTS statement must be used to
identify both the descriptor and the module defining the descriptor. identify both the descriptor and the module in which the descriptor is |
defined, where the module is identified by its ASN.1 module name. |
Note that when symbols from "enterprise-specific" information modules Note that when symbols from "enterprise-specific" information modules
are referenced (e.g., a descriptor), there is the possibility of are referenced (e.g., a descriptor), there is the possibility of
collision. As such, if different objects with the same descriptor are collision. As such, if different objects with the same descriptor are
IMPORTed, then this ambiguity is resolved by prefixing the descriptor IMPORTed, then this ambiguity is resolved by prefixing the descriptor
with the name of the information module and a dot ("."), i.e., with the name of the information module and a dot ("."), i.e.,
"module.descriptor" "module.descriptor"
(All descriptors must be unique within any information module.) (All descriptors must be unique within any information module.)
Of course, this notation can be used even when there is no collision Of course, this notation can be used even when there is no collision
when IMPORTing symbols. when IMPORTing symbols.
Finally, the IMPORTS statement may not be used to import an ASN.1 named Finally, the IMPORTS statement may not be used to import an ASN.1 named
type which corresponds to either the SEQUENCE or SEQUENCE OF type. type which corresponds to either the SEQUENCE or SEQUENCE OF type.
3.3. Exporting Symbols
The ASN.1 EXPORTS statement is not allowed in SNMPv2 information +
modules. All items defined in an information module are automatically +
exported. +
3.4. ASN.1 Comments +
Comments in ASN.1 commence with a pair of adjacent hyphens and end with +
the next pair of adjacent hyphens or at the end of the line, whichever +
occurs first. +
3.5. OBJECT IDENTIFIER values +
An OBJECT IDENTIFIER value is an ordered list of non-negative numbers. +
For the SNMPv2 framework, each number in the list is referred to as a +
sub-identifier, there are at most 128 sub-identifiers in a value, and +
each sub-identifier has a maximum value of 2^32-1 (4294967295 decimal). +
All OBJECT IDENTIFIER values have at least two sub-identifiers, where +
the value of the first sub-identifier is one of the following well-known +
names: +
Value Name +
0 ccitt +
1 iso +
2 joint-iso-ccitt +
4. Naming Hierarchy 4. Naming Hierarchy
The root of the subtree administered by the Internet Assigned Numbers The root of the subtree administered by the Internet Assigned Numbers
Authority (IANA) for the Internet is: Authority (IANA) for the Internet is:
internet OBJECT IDENTIFIER ::= { iso 3 6 1 } internet OBJECT IDENTIFIER ::= { iso 3 6 1 }
That is, the Internet subtree of OBJECT IDENTIFIERs starts with the That is, the Internet subtree of OBJECT IDENTIFIERs starts with the
prefix: prefix:
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products. products.
5. Mapping of the MODULE-IDENTITY macro 5. Mapping of the MODULE-IDENTITY macro
The MODULE-IDENTITY macro is used to provide contact and revision The MODULE-IDENTITY macro is used to provide contact and revision
history for each information module. It must appear exactly once in history for each information module. It must appear exactly once in
every information module. It should be noted that the expansion of the every information module. It should be noted that the expansion of the
MODULE-IDENTITY macro is something which conceptually happens during MODULE-IDENTITY macro is something which conceptually happens during
implementation and not during run-time. implementation and not during run-time.
Note that reference in an IMPORTS clause or in clauses of SNMPv2 macros +
to an information module is NOT through the use of the 'descriptor' of a +
MODULE-IDENTITY macro; rather, an information module is referenced +
through specifying its module name. +
5.1. Mapping of the LAST-UPDATED clause 5.1. Mapping of the LAST-UPDATED clause
The LAST-UPDATED clause, which must be present, contains the date and The LAST-UPDATED clause, which must be present, contains the date and
time that this information module was last edited. The date and time + time that this information module was last edited. The date and time
are represented in UTC Time format (see Appendix B). + are represented in UTC Time format (see Appendix B).
5.2. Mapping of the ORGANIZATION clause 5.2. Mapping of the ORGANIZATION clause
The ORGANIZATION clause, which must be present, contains a textual The ORGANIZATION clause, which must be present, contains a textual
description of the organization under whose auspices this information description of the organization under whose auspices this information
module was developed. module was developed.
5.3. Mapping of the CONTACT-INFO clause 5.3. Mapping of the CONTACT-INFO clause
The CONTACT-INFO clause, which must be present, contains the name, The CONTACT-INFO clause, which must be present, contains the name,
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person to whom technical queries concerning this information module person to whom technical queries concerning this information module
should be sent. should be sent.
5.4. Mapping of the DESCRIPTION clause 5.4. Mapping of the DESCRIPTION clause
The DESCRIPTION clause, which must be present, contains a high-level The DESCRIPTION clause, which must be present, contains a high-level
textual description of the contents of this information module. textual description of the contents of this information module.
5.5. Mapping of the REVISION clause 5.5. Mapping of the REVISION clause
The REVISION clause, which need not be present, is repeatedly used to The REVISION clause, which need not be present, is repeatedly used to |
describe the revisions made to this information module, in reverse describe the revisions (including the initial version) made to this |
chronological order. Each instance of this clause contains the date and information module, in reverse chronological order (i.e., most recent |
time of the revision. The date and time are represented in UTC Time + first). |
format (see Appendix B). + Each instance of this clause contains the date and time of the revision.
The date and time are represented in UTC Time format (see Appendix B).
5.6. Mapping of the DESCRIPTION clause 5.5.1. Mapping of the DESCRIPTION sub-clause
The DESCRIPTION clause, which must be present for each REVISION clause, The DESCRIPTION clause, which must be present for each REVISION clause,
contains a high-level textual description of the revision identified in contains a high-level textual description of the revision identified in
that REVISION clause. that REVISION clause.
5.7. Mapping of the MODULE-IDENTITY value 5.6. Mapping of the MODULE-IDENTITY value
The value of an invocation of the MODULE-IDENTITY macro is an OBJECT The value of an invocation of the MODULE-IDENTITY macro is an OBJECT
IDENTIFIER. As such, this value may be authoritatively used when IDENTIFIER. As such, this value may be authoritatively used when |
referring to the information module containing the invocation. specifying an OBJECT IDENTIFIER value to refer to the information module |
containing the invocation. |
5.8. Usage Example 5.7. Usage Example
Consider how a skeletal MIB module might be constructed: e.g., Consider how a skeletal MIB module might be constructed: e.g.,
FIZBIN-MIB DEFINITIONS ::= BEGIN FIZBIN-MIB DEFINITIONS ::= BEGIN
IMPORTS IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, experimental MODULE-IDENTITY, OBJECT-TYPE, experimental
FROM SNMPv2-SMI; FROM SNMPv2-SMI;
fizbin MODULE-IDENTITY fizbin MODULE-IDENTITY
LAST-UPDATED "9310070433Z" LAST-UPDATED "9505241811Z" |
ORGANIZATION "IETF SNMPv2 Working Group" ORGANIZATION "IETF SNMPv2 Working Group"
CONTACT-INFO CONTACT-INFO
" Marshall T. Rose " Marshall T. Rose
Postal: Dover Beach Consulting, Inc. Postal: Dover Beach Consulting, Inc.
420 Whisman Court 420 Whisman Court
Mountain View, CA 94043-2186 Mountain View, CA 94043-2186
US US
Tel: +1 415 968 1052 Tel: +1 415 968 1052
Fax: +1 415 968 2510 Fax: +1 415 968 2510
E-mail: mrose@dbc.mtview.ca.us" E-mail: mrose@dbc.mtview.ca.us"
DESCRIPTION DESCRIPTION
"The MIB module for entities implementing the xxxx "The MIB module for entities implementing the xxxx
protocol." protocol."
REVISION "9505241811Z" +
DESCRIPTION +
"The latest version of this MIB module." +
REVISION "9210070433Z" REVISION "9210070433Z"
DESCRIPTION DESCRIPTION
"Initial version of this MIB module." "The initial version of this MIB module." |
-- contact IANA for actual number -- contact IANA for actual number
::= { experimental xx } ::= { experimental xx }
END END
6. Mapping of the OBJECT-IDENTITY macro 6. Mapping of the OBJECT-IDENTITY macro
The OBJECT-IDENTITY macro is used to define information about an OBJECT | The OBJECT-IDENTITY macro is used to define information about an OBJECT
IDENTIFIER assignment. All administrative OBJECT IDENTIFIER assignments | IDENTIFIER assignment. All administrative OBJECT IDENTIFIER assignments
which define a type identification value (see AutonomousType, a textual | which define a type identification value (see AutonomousType, a textual
convention defined in [3]) should be defined via the OBJECT-IDENTITY | convention defined in [3]) should be defined via the OBJECT-IDENTITY
macro. | macro. It should be noted that the expansion of the OBJECT-IDENTITY
It should be noted that the expansion of the OBJECT-IDENTITY macro is macro is something which conceptually happens during implementation and
something which conceptually happens during implementation and not not during run-time.
during run-time.
6.1. Mapping of the STATUS clause 6.1. Mapping of the STATUS clause
The STATUS clause, which must be present, indicates whether this The STATUS clause, which must be present, indicates whether this
definition is current or historic. definition is current or historic.
The values "current", and "obsolete" are self-explanatory. The + The values "current", and "obsolete" are self-explanatory. The
"deprecated" value indicates that the definition is obsolete, but that + "deprecated" value indicates that the definition is obsolete, but that
an implementor may wish to support it to foster interoperability with + an implementor may wish to support it to foster interoperability with
older implementations. + older implementations.
6.2. Mapping of the DESCRIPTION clause 6.2. Mapping of the DESCRIPTION clause
The DESCRIPTION clause, which must be present, contains a textual The DESCRIPTION clause, which must be present, contains a textual
description of the object assignment. description of the object assignment.
6.3. Mapping of the REFERENCE clause 6.3. Mapping of the REFERENCE clause
The REFERENCE clause, which need not be present, contains a textual The REFERENCE clause, which need not be present, contains a textual
cross-reference to an object assignment defined in some other cross-reference to an object assignment defined in some other
skipping to change at page 23, line 7 skipping to change at page 24, line 7
Consider how an OBJECT IDENTIFIER assignment might be made: e.g., Consider how an OBJECT IDENTIFIER assignment might be made: e.g.,
fizbin69 OBJECT-IDENTITY fizbin69 OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The authoritative identity of the Fizbin 69 chipset." "The authoritative identity of the Fizbin 69 chipset."
::= { fizbinChipSets 1 } ::= { fizbinChipSets 1 }
7. Mapping of the OBJECT-TYPE macro 7. Mapping of the OBJECT-TYPE macro
The OBJECT-TYPE macro is used to define a managed object. It should be The OBJECT-TYPE macro is used to define a type of managed object. |
noted that the expansion of the OBJECT-TYPE macro is something which It should be noted that the expansion of the OBJECT-TYPE macro is
conceptually happens during implementation and not during run-time. 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 the object are identified by +
appending a sub-identifier of zero to the name of that object. +
Otherwise, the INDEX clause of the conceptual row object superior to a +
columnar object defines instance identification information. +
7.1. Mapping of the SYNTAX clause 7.1. Mapping of the SYNTAX clause
The SYNTAX clause, which must be present, defines the abstract data The SYNTAX clause, which must be present, defines the abstract data
structure corresponding to that object. The data structure must be one structure corresponding to that object. The data structure must be one |
of the alternatives defined in the ObjectSyntax CHOICE or the BITS | of the following: a base type, the BITS construct, or a textual |
construct. | convention. (SEQUENCE OF and SEQUENCE are also possible for conceptual |
tables, see section 7.1.12). The base types are those defined in the |
ObjectSyntax CHOICE. A textual convention is a newly-defined type |
defined as a sub-type of a base type [3]. |
A extended subset of the full capabilities of ASN.1 sub-typing is | A extended subset of the full capabilities of ASN.1 sub-typing is
allowed, as appropriate to the underingly ASN.1 type. | allowed, as appropriate to the underingly ASN.1 type. Any such
Any such restriction on size, range, enumerations or repertoire restriction on size, range, enumerations or repertoire specified in this
specified in this clause represents the maximal level of support which clause represents the maximal level of support which makes "protocol
makes "protocol sense". Restrictions on sub-typing are specified in sense". Restrictions on sub-typing are specified in detail in Section 9
detail in Section 9 and Appendix C of this memo. | and Appendix C of this memo.
The semantics of ObjectSyntax are now described. The semantics of ObjectSyntax are now described.
7.1.1. Integer32 and INTEGER 7.1.1. Integer32 and INTEGER
The Integer32 type represents integer-valued information between -2^31 The Integer32 type represents integer-valued information between -2^31
and 2^31-1 inclusive (-2147483648 to 2147483647 decimal). This type is and 2^31-1 inclusive (-2147483648 to 2147483647 decimal). This type is
indistinguishable from the INTEGER type. Both the INTEGER and Integer32 + indistinguishable from the INTEGER type. Both the INTEGER and Integer32
types may be sub-typed to be more constrained than the Integer32 type. + types may be sub-typed to be more constrained than the Integer32 type.
The INTEGER type may also be used to represent integer-valued
information as named-number enumerations. In this case, only those
named-numbers so enumerated may be present as a value. Note that
although it is recommended that enumerated values start at 1 and be
The INTEGER type may also be used to represent integer-valued |
information as named-number enumerations. In this case, |
only those named-numbers so enumerated may be present as a value. Note
that although it is recommended that enumerated values start at 1 and be
numbered contiguously, any valid value for Integer32 is allowed for an numbered contiguously, any valid value for Integer32 is allowed for an
enumerated value and, further, enumerated values needn't be contiguously enumerated value and, further, enumerated values needn't be contiguously
assigned. assigned.
Finally, a label for a named-number enumeration must consist of one or Finally, a label for a named-number enumeration must consist of one or
more letters or digits (no hyphens), up to a maximum of 64 characters, more letters or digits (no hyphens), up to a maximum of 64 characters,
and the initial character must be a lower-case letter. and the initial character must be a lower-case letter. (However, labels +
longer than 32 characters are not recommended.) +
7.1.2. OCTET STRING 7.1.2. OCTET STRING
The OCTET STRING type represents arbitrary binary or textual data. The OCTET STRING type represents arbitrary binary or textual data.
Although there is no SMI-specified size limitation for this type, MIB Although there is no SMI-specified size limitation for this type, MIB
designers should realize that there may be implementation and designers should realize that there may be implementation and
interoperability limitations for sizes in excess of 255 octets. interoperability limitations for sizes in excess of 255 octets.
7.1.3. OBJECT IDENTIFIER 7.1.3. OBJECT IDENTIFIER
The OBJECT IDENTIFIER type represents administratively assigned names. The OBJECT IDENTIFIER type represents administratively assigned names.
Any instance of this type may have at most 128 sub-identifiers. Any instance of this type may have at most 128 sub-identifiers.
Further, each sub-identifier must not exceed the value 2^32-1 Further, each sub-identifier must not exceed the value 2^32-1
(4294967295 decimal). (4294967295 decimal).
7.1.4. The BITS construct 7.1.4. The BITS construct
The BITS construct represents an enumeration of named bits. | The BITS construct represents an enumeration of named bits. This
This collection is assigned non-negative, contiguous values, starting at collection is assigned non-negative, contiguous values, starting at
zero. Only those named-bits so enumerated may be present in a value. zero. Only those named-bits so enumerated may be present in a value. |
(Thus, enumerations must be assigned to consecutive bits). (Thus, enumerations must be assigned to consecutive bits; however, see |
Section 9 for refinements of an object with this syntax.) |
Although there is no SMI-specified limitation on the number of - Although there is no SMI-specified limitation on the number of
enumerations (and therefore on the length of a value), MIB designers enumerations (and therefore on the length of a value), MIB designers
should realize that there may be implementation and interoperability | should realize that there may be implementation and interoperability
limitations for sizes in excess of 128 bits. | limitations for sizes in excess of 128 bits.
Finally, a label for a named-number enumeration must consist of one or Finally, a label for a named-number enumeration must consist of one or
more letters or digits (no hyphens), up to a maximum of 64 characters, more letters or digits (no hyphens), up to a maximum of 64 characters,
and the initial character must be a lower-case letter. and the initial character must be a lower-case letter. (However, labels +
longer than 32 characters are not recommended.) +
7.1.5. IpAddress 7.1.5. IpAddress
The IpAddress type represents a 32-bit internet address. It is The IpAddress type represents a 32-bit internet address. It is
represented as an OCTET STRING of length 4, in network byte-order. represented as an OCTET STRING of length 4, in network byte-order.
Note that the IpAddress type is a tagged type for historical reasons. Note that the IpAddress type is a tagged type for historical reasons.
Network addresses should be represented using an invocation of the Network addresses should be represented using an invocation of the
TEXTUAL-CONVENTION macro [3]. TEXTUAL-CONVENTION macro [3].
skipping to change at page 25, line 21 skipping to change at page 26, line 30
Counters have no defined "initial" value, and thus, a single value of a Counters have no defined "initial" value, and thus, a single value of a
Counter has (in general) no information content. Discontinuities in the Counter has (in general) no information content. Discontinuities in the
monotonically increasing value normally occur at re-initialization of monotonically increasing value normally occur at re-initialization of
the management system, and at other times as specified in the the management system, and at other times as specified in the
description of an object-type using this ASN.1 type. If such other 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 can occur, for example, the creation of an object instance at
times other than re-initialization, then a corresponding object should times other than re-initialization, then a corresponding object should
be defined with a SYNTAX clause value of TimeStamp (a textual convention be defined with a SYNTAX clause value of TimeStamp (a textual convention
defined in [3]) indicating the time of the last discontinuity. defined in [3]) indicating the time of the last discontinuity.
The value of the MAX-ACCESS clause for objects with a SYNTAX clause | The value of the MAX-ACCESS clause for objects with a SYNTAX clause
value of Counter32 is either "read-only" or "accessible-for-notify". | value of Counter32 is either "read-only" or "accessible-for-notify".
A DEFVAL clause is not allowed for objects with a SYNTAX clause value of A DEFVAL clause is not allowed for objects with a SYNTAX clause value of
Counter32. Counter32.
7.1.7. Gauge32 7.1.7. Gauge32
The Gauge32 type represents a non-negative integer, which may increase The Gauge32 type represents a non-negative integer, which may increase
or decrease, but shall never exceed a maximum value. The maximum value or decrease, but shall never exceed a maximum value. The maximum value
can not be greater than 2^32-1 (4294967295 decimal). The value of a can not be greater than 2^32-1 (4294967295 decimal). The value of a
Gauge has its maximum value whenever the information being modeled is Gauge has its maximum value whenever the information being modeled is
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string of octets. This, in turn, is encoded as an OCTET STRING, in string of octets. This, in turn, is encoded as an OCTET STRING, in
effect "double-wrapping" the original ASN.1 value. effect "double-wrapping" the original ASN.1 value.
Note that a conforming implementation need only be able to accept and Note that a conforming implementation need only be able to accept and
recognize opaquely-encoded data. It need not be able to unwrap the data recognize opaquely-encoded data. It need not be able to unwrap the data
and then interpret its contents. and then interpret its contents.
A requirement on "standard" MIB modules is that no object may have a A requirement on "standard" MIB modules is that no object may have a
SYNTAX clause value of Opaque. SYNTAX clause value of Opaque.
7.1.10. NsapAddress 7.1.10. Counter64 -
The NsapAddress type represents an OSI address as a variable-length
OCTET STRING. The first octet of the string contains a binary value in
the range of 0..20, and indicates the length in octets of the NSAP.
Following the first octet, is the NSAP, expressed in concrete binary
notation, starting with the most significant octet. A zero-length NSAP
is used as a "special" address meaning "the default NSAP" (analogous to
the IP address of 0.0.0.0). Such an NSAP is encoded as a single octet,
containing the value 0. All other NSAPs are encoded in at least 4
octets.
Note that the NsapAddress type is a tagged type for historical reasons.
Network addresses should be represented using an invocation of the
TEXTUAL-CONVENTION macro [3].
7.1.11. Counter64
The Counter64 type represents a non-negative integer which monotonically The Counter64 type represents a non-negative integer which monotonically
increases until it reaches a maximum value of 2^64-1 increases until it reaches a maximum value of 2^64-1
(18446744073709551615 decimal), when it wraps around and starts (18446744073709551615 decimal), when it wraps around and starts
increasing again from zero. increasing again from zero.
Counters have no defined "initial" value, and thus, a single value of a Counters have no defined "initial" value, and thus, a single value of a
Counter has (in general) no information content. Discontinuities in the Counter has (in general) no information content. Discontinuities in the
monotonically increasing value normally occur at re-initialization of monotonically increasing value normally occur at re-initialization of
the management system, and at other times as specified in the the management system, and at other times as specified in the
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The Counter64 type represents a non-negative integer which monotonically The Counter64 type represents a non-negative integer which monotonically
increases until it reaches a maximum value of 2^64-1 increases until it reaches a maximum value of 2^64-1
(18446744073709551615 decimal), when it wraps around and starts (18446744073709551615 decimal), when it wraps around and starts
increasing again from zero. increasing again from zero.
Counters have no defined "initial" value, and thus, a single value of a Counters have no defined "initial" value, and thus, a single value of a
Counter has (in general) no information content. Discontinuities in the Counter has (in general) no information content. Discontinuities in the
monotonically increasing value normally occur at re-initialization of monotonically increasing value normally occur at re-initialization of
the management system, and at other times as specified in the the management system, and at other times as specified in the
description of an object-type using this ASN.1 type. If such other 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 can occur, for example, the creation of an object instance at
times other than re-initialization, then a corresponding object should times other than re-initialization, then a corresponding object should
be defined with a SYNTAX clause value of TimeStamp (a textual convention be defined with a SYNTAX clause value of TimeStamp (a textual convention
defined in [3]) indicating the time of the last discontinuity. defined in [3]) indicating the time of the last discontinuity.
The value of the MAX-ACCESS clause for objects with a SYNTAX clause | The value of the MAX-ACCESS clause for objects with a SYNTAX clause
value of Counter64 is either "read-only" or "accessible-for-notify". | value of Counter64 is either "read-only" or "accessible-for-notify".
A requirement on "standard" MIB modules is that the Counter64 type may 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 be used only if the information being modeled would wrap in less than
one hour if the Counter32 type was used instead. one hour if the Counter32 type was used instead.
A DEFVAL clause is not allowed for objects with a SYNTAX clause value of A DEFVAL clause is not allowed for objects with a SYNTAX clause value of
Counter64. Counter64.
7.1.12. Unsigned32 7.1.11. Unsigned32
The Unsigned32 type represents integer-valued information | The Unsigned32 type represents integer-valued information between 0 and
between 0 and 2^32-1 inclusive (0 to 4294967295 decimal). 2^32-1 inclusive (0 to 4294967295 decimal).
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 may contain one 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 a table +
and an object which corresponds to a row in that table. A conceptual +
table has SYNTAX of the form: +
SEQUENCE OF <EntryType> +
where <EntryType> refers to the SEQUENCE type of its subordinate +
conceptual row. A conceptual row has SYNTAX of the form: +
<EntryType> +
where <EntryType> 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 the form: +
<descriptor> <syntax> +
where <descriptor> is the descriptor naming a subordinate object, and +
<syntax> has the value of that subordinate object's SYNTAX clause, +
normally omitting the sub-typing information. Further, these ASN.1 +
types are always present (the DEFAULT and OPTIONAL clauses are +
disallowed in the SEQUENCE definition). The MAX-ACCESS clause for +
conceptual tables and rows is "not-accessible". +
7.1.12.1. Creation and Deletion of Conceptual Rows +
For newly-defined conceptual rows which allow the creation of new object +
instances and/or the deletion of existing object instances, there should +
be one columnar object with a SYNTAX clause value of RowStatus (a +
textual convention defined in [3]) and a 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 7.2. Mapping of the UNITS clause
This UNITS clause, which need not be present, contains a textual This UNITS clause, which need not be present, contains a textual
definition of the units associated with that object. definition of the units associated with that object.
7.3. Mapping of the MAX-ACCESS clause 7.3. Mapping of the MAX-ACCESS clause
The MAX-ACCESS clause, which must be present, defines whether it makes The MAX-ACCESS clause, which must be present, defines whether it makes
"protocol sense" to read, write and/or create an instance of the object, | "protocol sense" to read, write and/or create an instance of the object,
or to include its value in a notification. | or to include its value in a notification. This is the maximal level of
This is the maximal level of access for the object. (This maximal level access for the object. (This maximal level of access is independent of
of access is independent of any administrative authorization policy.) any administrative authorization policy.)
The value "read-write" indicates that read and write access make The value "read-write" indicates that read and write access make
"protocol sense", but create does not. The value "read-create" "protocol sense", but create does not. The value "read-create"
indicates that read, write and create access make "protocol sense". The | indicates that read, write and create access make "protocol sense". The
value "not-accessible" indicates an auxiliary object (see Section 7.7). | value "not-accessible" indicates an auxiliary object (see Section 7.7).
The value "accessible-for-notify" indicates an object which is
The value "accessible-for-notify" indicates an object which is | accessible only via a notification (e.g., snmpTrapOID [5]).
accessible only via a notification |
(e.g., snmpTrapOID [5]).
These values are ordered, from least to greatest: "not-accessible", + These values are ordered, from least to greatest: "not-accessible",
"accessible-for-notify", + "accessible-for-notify", "read-only", "read-write", "read-create".
"read-only", "read-write", "read-create".
If any columnar object in a conceptual row has "read-create" as its If any columnar object in a conceptual row has "read-create" as its
maximal level of access, then no other columnar object of the same maximal level of access, then no other columnar object of the same
conceptual row may have a maximal access of "read-write". (Note that conceptual row may have a maximal access of "read-write". (Note that
"read-create" is a superset of "read-write".) "read-create" is a superset of "read-write".)
7.4. Mapping of the STATUS clause 7.4. Mapping of the STATUS clause
The STATUS clause, which must be present, indicates whether this The STATUS clause, which must be present, indicates whether this
definition is current or historic. definition is current or historic.
The values "current", and "obsolete" are self-explanatory. The The values "current", and "obsolete" are self-explanatory. The |
"deprecated" value indicates that the object is obsolete, but that an "deprecated" value indicates that the definition is obsolete, |
implementor may wish to support that object to foster interoperability but that an implementor may wish to support that object to foster
with older implementations. interoperability with older implementations.
7.5. Mapping of the DESCRIPTION clause 7.5. Mapping of the DESCRIPTION clause
The DESCRIPTION clause, which must be present, contains a textual The DESCRIPTION clause, which must be present, contains a textual
definition of that object which provides all semantic definitions definition of that object which provides all semantic definitions
necessary for implementation, and should embody any information which necessary for implementation, and should embody any information which
would otherwise be communicated in any ASN.1 commentary annotations would otherwise be communicated in any ASN.1 commentary annotations
associated with the object. associated with the object.
7.6. Mapping of the REFERENCE clause 7.6. Mapping of the REFERENCE clause
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This is useful when de-osifying a MIB module produced by some other This is useful when de-osifying a MIB module produced by some other
organization. organization.
7.7. Mapping of the INDEX clause 7.7. Mapping of the INDEX clause
The INDEX clause, which must be present if that object corresponds to a The INDEX clause, which must be present if that object corresponds to a
conceptual row (unless an AUGMENTS clause is present instead), and must conceptual row (unless an AUGMENTS clause is present instead), and must
be absent otherwise, defines instance identification information for the be absent otherwise, defines instance identification information for the
columnar objects subordinate to that object. columnar objects subordinate to that object.
Management operations apply exclusively to scalar objects. However, it The instance identification information in an INDEX clause must specify -
is convenient for developers of management applications to impose
imaginary, tabular structures on the ordered collection of objects that
constitute the MIB. Each such conceptual table contains zero or more
rows, and each row may contain one 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 a table
and an object which corresponds to a row in that table. A conceptual
table has SYNTAX of the form:
SEQUENCE OF <EntryType>
where <EntryType> refers to the SEQUENCE type of its subordinate
conceptual row. A conceptual row has SYNTAX of the form:
<EntryType>
where <EntryType> 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 the form:
<descriptor> <syntax>
where <descriptor> is the descriptor naming a subordinate object, and
<syntax> has the value of that subordinate object's SYNTAX clause,
optionally omitting the sub-typing information. Further, these ASN.1
types are always present (the DEFAULT and OPTIONAL clauses are
disallowed in the SEQUENCE definition). The MAX-ACCESS clause for
conceptual tables and rows is "not-accessible".
For leaf objects which are not columnar objects, instances of the object
are identified by appending a sub-identifier of zero to the name of that
object. Otherwise, the INDEX clause of the conceptual row object
superior to a columnar object defines instance identification
information.
The instance identification information in an INDEX clause must specify
object(s) such that value(s) of those object(s) will unambiguously object(s) such that value(s) of those object(s) will unambiguously
distinguish a conceptual row. The syntax of those objects indicate how distinguish a conceptual row. The syntax of those objects indicate how
to form the instance-identifier: to form the instance-identifier:
(1) integer-valued: a single sub-identifier taking the integer value (1) integer-valued: a single sub-identifier taking the integer value
(this works only for non-negative integers); (this works only for non-negative integers);
(2) string-valued, fixed-length strings (or variable-length preceded by (2) string-valued, fixed-length strings (or variable-length preceded by
the IMPLIED keyword): `n' sub-identifiers, where `n' is the length the IMPLIED keyword): `n' sub-identifiers, where `n' is the length
of the string (each octet of the string is encoded in a separate of the string (each octet of the string is encoded in a separate
skipping to change at page 30, line 36 skipping to change at page 31, line 36
separate sub-identifier); separate sub-identifier);
(5) object identifier-valued (when not preceded by the IMPLIED (5) object identifier-valued (when not preceded by the IMPLIED
keyword): `n+1' sub-identifiers, where `n' is the number of sub- keyword): `n+1' sub-identifiers, where `n' is the number of sub-
identifiers in the value (the first sub-identifier is `n' itself, identifiers in the value (the first sub-identifier is `n' itself,
following this, each sub-identifier in the value is copied); following this, each sub-identifier in the value is copied);
(6) IpAddress-valued: 4 sub-identifiers, in the familiar a.b.c.d (6) IpAddress-valued: 4 sub-identifiers, in the familiar a.b.c.d
notation. notation.
(7) NsapAddress-valued: `n' sub-identifiers, where `n' is the length of Note that the IMPLIED keyword can only be present for an object having a
the value (each octet of the value is encoded in a separate sub- variable-length syntax (e.g., variable-length strings or object
identifier); identifier-valued objects), Further, the IMPLIED keyword can only be
associated with the last object in the INDEX clause. Finally, the
Note that the IMPLIED keyword can only be present for an object having a | IMPLIED keyword may not be used on a variable-length string object if
variable-length syntax (e.g., variable-length strings or object | that string might have a value of zero-length.
identifier-valued objects), |
Further, the IMPLIED keyword can only be associated with the last object |
in the INDEX clause. |
Finally, the IMPLIED keyword may not be used on a variable-length string
object if that string might have a value of zero-length.
Instances identified by use of integer-valued objects should be numbered Instances identified by use of integer-valued objects should be numbered
starting from one (i.e., not from zero). The use of zero as a value for starting from one (i.e., not from zero). The use of zero as a value for
an integer-valued index object should be avoided, except in special an integer-valued index object should be avoided, except in special
cases. cases.
Objects which are both specified in the INDEX clause of a conceptual row Objects which are both specified in the INDEX clause of a conceptual row
and also columnar objects of the same conceptual row are termed and also columnar objects of the same conceptual row are termed
auxiliary objects. The MAX-ACCESS clause for auxiliary objects is auxiliary objects. The MAX-ACCESS clause for auxiliary objects is
"not-accessible", except in the following circumstances: "not-accessible", except in the following circumstances:
(1) within a MIB module originally written to conform to the SNMPv1 (1) within a MIB module originally written to conform to the SNMPv1
framework, and later converted to conform to the SNMPv2 framework; framework, and later converted to conform to the SNMPv2 framework;
or or
(2) a conceptual row must contain at least one columnar object which is (2) a conceptual row must contain at least one columnar object which is
not an auxiliary object. In the event that all of a conceptual not an auxiliary object. In the event that all of a conceptual
row's columnar objects are also specified in its INDEX clause, then row's columnar objects are also specified in its INDEX clause, then
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auxiliary objects. The MAX-ACCESS clause for auxiliary objects is auxiliary objects. The MAX-ACCESS clause for auxiliary objects is
"not-accessible", except in the following circumstances: "not-accessible", except in the following circumstances:
(1) within a MIB module originally written to conform to the SNMPv1 (1) within a MIB module originally written to conform to the SNMPv1
framework, and later converted to conform to the SNMPv2 framework; framework, and later converted to conform to the SNMPv2 framework;
or or
(2) a conceptual row must contain at least one columnar object which is (2) a conceptual row must contain at least one columnar object which is
not an auxiliary object. In the event that all of a conceptual not an auxiliary object. In the event that all of a conceptual
row's columnar objects are also specified in its INDEX clause, then row's columnar objects are also specified in its INDEX clause, then
one of them must be accessible (i.e., have a MAX-ACCESS clause of one of them must be accessible, i.e., have a MAX-ACCESS clause of |
either "read-only" or "read-create"). "read-only". (Note that this situation does not arise for a |
conceptual row allowing create access, since such a row will have a |
status column which will not be an auxiliary object.) |
Note that objects specified in a conceptual row's INDEX clause need not Note that objects specified in a conceptual row's INDEX clause need not
be columnar objects of that conceptual row. In this situation, the be columnar objects of that conceptual row. In this situation, the
DESCRIPTION clause of the conceptual row must include a textual DESCRIPTION clause of the conceptual row must include a textual
explanation of how the objects which are included in the INDEX clause explanation of how the objects which are included in the INDEX clause
but not columnar objects of that conceptual row, are used in uniquely but not columnar objects of that conceptual row, are used in uniquely
identifying instances of the conceptual row's columnar objects. identifying instances of the conceptual row's columnar objects.
7.7.1. Creation and Deletion of Conceptual Rows 7.8. Mapping of the AUGMENTS clause -
For newly-defined conceptual rows which allow the creation of new object
instances and/or the deletion of existing object instances, |
there should be one columnar object with a SYNTAX clause value of
RowStatus (a textual convention defined in [3]) and a MAX-ACCESS clause
value of read-create. By convention, this is termed the status column
for the conceptual row.
7.8. Mapping of the AUGMENTS clause
The AUGMENTS clause, which must not be present unless the object The AUGMENTS clause, which must not be present unless the object
corresponds to a conceptual row, is an alternative to the INDEX clause. corresponds to a conceptual row, is an alternative to the INDEX clause.
Every object corresponding to a conceptual row has either an INDEX Every object corresponding to a conceptual row has either an INDEX
clause or an AUGMENTS clause. clause or an AUGMENTS clause.
If an object corresponding to a conceptual row has an INDEX clause, that If an object corresponding to a conceptual row has an INDEX clause, that
row is termed a base conceptual row; alternatively, if the object has an row is termed a base conceptual row; alternatively, if the object has an
AUGMENTS clause, the row is said to be a conceptual row augmentation, AUGMENTS clause, the row is said to be a conceptual row augmentation,
where the AUGMENTS clause names the object corresponding to the base where the AUGMENTS clause names the object corresponding to the base
conceptual row which is augmented by this conceptual row augmentation. + conceptual row which is augmented by this conceptual row augmentation.
(Thus, a conceptual row augmentation cannot itself be augmented.) + (Thus, a conceptual row augmentation cannot itself be augmented.)
Instances of subordinate columnar objects of a conceptual row Instances of subordinate columnar objects of a conceptual row
augmentation are identified according to the INDEX clause of the base augmentation are identified according to the INDEX clause of the base
conceptual row corresponding to the object named in the AUGMENTS clause. conceptual row corresponding to the object named in the AUGMENTS clause.
Further, instances of subordinate columnar objects of a conceptual row Further, instances of subordinate columnar objects of a conceptual row
augmentation exist according to the same semantics as instances of augmentation exist according to the same semantics as instances of
subordinate columnar objects of the base conceptual row being augmented. subordinate columnar objects of the base conceptual row being augmented.
As such, note that creation of a base conceptual row implies the As such, note that creation of a base conceptual row implies the
correspondent creation of any conceptual row augmentations. correspondent creation of any conceptual row augmentations.
For example, a MIB designer might wish to define additional columns in For example, a MIB designer might wish to define additional columns in
skipping to change at page 33, line 32 skipping to change at page 34, line 21
of sub-identifiers. of sub-identifiers.
Note that if an operand to the management protocol set operation is an Note that if an operand to the management protocol set operation is an
instance of a read-only object, then the error `notWritable' [6] will be instance of a read-only object, then the error `notWritable' [6] will be
returned. As such, the DEFVAL clause can be used to provide an returned. As such, the DEFVAL clause can be used to provide an
acceptable default value that a SNMPv2 entity acting in an agent role acceptable default value that a SNMPv2 entity acting in an agent role
might use. might use.
By way of example, consider the following possible DEFVAL clauses: By way of example, consider the following possible DEFVAL clauses:
ObjectSyntax DEFVAL clause ObjectSyntax DEFVAL clause |
----------------- ------------ ---------------- ------------ |
Integer32 1 Integer32 DEFVAL { 1 } |
-- same for Gauge32, TimeTicks, Unsigned32 | -- same for Gauge32, TimeTicks, Unsigned32 |
INTEGER valid -- enumerated value INTEGER DEFVAL { valid } -- enumerated value |
OCTET STRING 'ffffffffffff'H OCTET STRING DEFVAL { 'ffffffffffff'H } |
OBJECT IDENTIFIER sysDescr OBJECT IDENTIFIER DEFVAL { sysDescr } |
BITS { primary, secondary } -- enumerated values | BITS DEFVAL { { primary, secondary } } |
IpAddress 'c0210415'H -- 192.33.4.21 -- enumerated values that are set |
IpAddress DEFVAL { 'c0210415'H } -- 192.33.4.21 |
Object types with SYNTAX of Counter32 and Counter64 may not have DEFVAL Object types with SYNTAX of Counter32 and Counter64 may not have DEFVAL
clauses, since they do not have defined initial values. However, it is clauses, since they do not have defined initial values. However, it is
recommended that they be initialized to zero. recommended that they be initialized to zero.
7.10. Mapping of the OBJECT-TYPE value 7.10. Mapping of the OBJECT-TYPE value
The value of an invocation of the OBJECT-TYPE macro is the name of the The value of an invocation of the OBJECT-TYPE macro is the name of the
object, which is an OBJECT IDENTIFIER, an administratively assigned object, which is an OBJECT IDENTIFIER, an administratively assigned
name. name.
skipping to change at page 35, line 7 skipping to change at page 36, line 7
Note that the final sub-identifier of any administratively assigned name Note that the final sub-identifier of any administratively assigned name
for an object shall be positive. A zero-valued final sub-identifier is for an object shall be positive. A zero-valued final sub-identifier is
reserved for future use. reserved for future use.
Further note that although conceptual tables and rows are given Further note that although conceptual tables and rows are given
administratively assigned names, these conceptual objects may not be administratively assigned names, these conceptual objects may not be
manipulated in aggregate form by the management protocol. manipulated in aggregate form by the management protocol.
7.11. Usage Example 7.11. Usage Example
Consider how one might define a conceptual table and its subordinates. + Consider how one might define a conceptual table and its subordinates.
(This example uses the RowStatus textual convention defined in [3].) + (This example uses the RowStatus textual convention defined in [3].)
evalSlot OBJECT-TYPE evalSlot OBJECT-TYPE
SYNTAX INTEGER SYNTAX INTEGER
MAX-ACCESS read-only MAX-ACCESS read-only
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The index number of the first unassigned entry in the "The index number of the first unassigned entry in the
evaluation table. evaluation table.
A management station should create new entries in the A management station should create new entries in the
evaluation table using this algorithm: first, issue a evaluation table using this algorithm: first, issue a
management protocol retrieval operation to determine the management protocol retrieval operation to determine the
value of evalSlot; and, second, issue a management protocol value of evalSlot; and, second, issue a management protocol
set operation to create an instance of the evalStatus object | set operation to create an instance of the evalStatus object
setting its value to createAndGo(4) or createAndWait(5). | setting its value to createAndGo(4) or createAndWait(5). If
If this latter operation succeeds, then the management this latter operation succeeds, then the management station
station may continue modifying the instances corresponding may continue modifying the instances corresponding to the
to the newly created conceptual row, without fear of newly created conceptual row, without fear of collision with
collision with other management stations." other management stations."
::= { eval 1 } ::= { eval 1 }
evalTable OBJECT-TYPE evalTable OBJECT-TYPE
SYNTAX SEQUENCE OF EvalEntry SYNTAX SEQUENCE OF EvalEntry
MAX-ACCESS not-accessible MAX-ACCESS not-accessible
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The (conceptual) evaluation table." "The (conceptual) evaluation table."
::= { eval 2 } ::= { eval 2 }
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The NOTIFICATION-TYPE macro is used to define the information contained The NOTIFICATION-TYPE macro is used to define the information contained
within an unsolicited transmission of management information (i.e., within an unsolicited transmission of management information (i.e.,
within either a SNMPv2-Trap-PDU or InformRequest-PDU). It should be within either a SNMPv2-Trap-PDU or InformRequest-PDU). It should be
noted that the expansion of the NOTIFICATION-TYPE macro is something noted that the expansion of the NOTIFICATION-TYPE macro is something
which conceptually happens during implementation and not during run- which conceptually happens during implementation and not during run-
time. time.
8.1. Mapping of the OBJECTS clause 8.1. Mapping of the OBJECTS clause
The OBJECTS clause, which need not be present, defines the ordered The OBJECTS clause, which need not be present, defines the ordered |
sequence of MIB objects which are contained within every instance of the sequence of MIB object types which are contained within every instance |
notification. of |
the notification. An object type specified in this clause may not have +
an MAX-ACCESS clause of "not-accessible". +
8.2. Mapping of the STATUS clause 8.2. Mapping of the STATUS clause
The STATUS clause, which must be present, indicates whether this The STATUS clause, which must be present, indicates whether this
definition is current or historic. definition is current or historic.
The values "current", and "obsolete" are self-explanatory. The The values "current", and "obsolete" are self-explanatory. The |
"deprecated" value indicates that the notification is obsolete, but that "deprecated" value indicates that the definition is obsolete, but that |
an implementor may wish to support that object to foster an implementor may wish to support the notification to foster |
interoperability with older implementations. interoperability with older implementations.
8.3. Mapping of the DESCRIPTION clause 8.3. Mapping of the DESCRIPTION clause
The DESCRIPTION clause, which must be present, contains a textual The DESCRIPTION clause, which must be present, contains a textual
definition of the notification which provides all semantic definitions definition of the notification which provides all semantic definitions
necessary for implementation, and should embody any information which necessary for implementation, and should embody any information which
would otherwise be communicated in any ASN.1 commentary annotations would otherwise be communicated in any ASN.1 commentary annotations |
associated with the object. In particular, the DESCRIPTION clause associated with the notification. |
should document which instances of the objects mentioned in the OBJECTS In particular, the DESCRIPTION clause should document which instances of
clause should be contained within notifications of this type. the objects mentioned in the OBJECTS clause should be contained within
notifications of this type.
8.4. Mapping of the REFERENCE clause 8.4. Mapping of the REFERENCE clause
The REFERENCE clause, which need not be present, contains a textual The REFERENCE clause, which need not be present, contains a textual
cross-reference to a notification defined in some other information cross-reference to a notification defined in some other information
module. This is useful when de-osifying a MIB module produced by some module. This is useful when de-osifying a MIB module produced by some
other organization. other organization.
8.5. Mapping of the NOTIFICATION-TYPE value 8.5. Mapping of the NOTIFICATION-TYPE value
The value of an invocation of the NOTIFICATION-TYPE macro is the name of The value of an invocation of the NOTIFICATION-TYPE macro is the name of
the notification, which is an OBJECT IDENTIFIER, an administratively the notification, which is an OBJECT IDENTIFIER, an administratively
assigned name. In order to achieve compatibility with the procedures + assigned name. In order to achieve compatibility with the procedures
employed by proxy agents (see Section 3.1.2 of [8]), the next to last + employed by proxy agents (see Section 3.1.2 of [8]), the next to last
sub-identifier in the name of any newly-defined notification must have + sub-identifier in the name of any newly-defined notification must have
the value zero. + the value zero.
Sections 4.2.6 and 4.2.7 of [6] describe how the NOTIFICATION-TYPE macro Sections 4.2.6 and 4.2.7 of [6] describe how the NOTIFICATION-TYPE macro
is used to generate a SNMPv2-Trap-PDU or InformRequest-PDU, is used to generate a SNMPv2-Trap-PDU or InformRequest-PDU,
respectively. respectively.
8.6. Usage Example 8.6. Usage Example
Consider how a linkUp trap might be described: Consider how a linkUp trap might be described:
linkUp NOTIFICATION-TYPE linkUp NOTIFICATION-TYPE
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links represented in its configuration has come up." links represented in its configuration has come up."
::= { snmpTraps 4 } ::= { snmpTraps 4 }
According to this invocation, the trap authoritatively identified as According to this invocation, the trap authoritatively identified as
{ snmpTraps 4 } { snmpTraps 4 }
is used to report a link coming up. is used to report a link coming up.
Note that a SNMPv2 entity acting in an agent role can be configured to Note that a SNMPv2 entity acting in an agent role can be configured to
send this trap to zero or more SNMPv2 entities acting in a manager role, | send this trap to zero or more SNMPv2 entities acting in a manager role,
depending on the contents of the acTable and viewTable [7] tables. | depending on the contents of the acTable and viewTable [7] tables. For
For example, by judicious use of the viewTable, a SNMPv2 entity acting example, by judicious use of the viewTable, a SNMPv2 entity acting in an
in an agent role might be configured to send all linkUp traps to one agent role might be configured to send all linkUp traps to one
particular SNMPv2 entity, and linkUp traps for only certain interfaces particular SNMPv2 entity, and linkUp traps for only certain interfaces
to other SNMPv2 entities. to other SNMPv2 entities.
9. Refined Syntax 9. Refined Syntax
Some macros have clauses which allows syntax to be refined, Some macros have clauses which allows syntax to be refined,
specifically: the SYNTAX clause of the OBJECT-TYPE macro, and the specifically: the SYNTAX clause of the OBJECT-TYPE macro, and the
SYNTAX/WRITE-SYNTAX clauses of the MODULE-COMPLIANCE and AGENT- SYNTAX/WRITE-SYNTAX clauses of the MODULE-COMPLIANCE and AGENT-
CAPABILITIES macros [2]. However, not all refinements of syntax are CAPABILITIES macros [2]. However, not all refinements of syntax are
appropriate. In particular, the object's primitive or application type appropriate. In particular, the object's primitive or application type
must not be changed. must not be changed.
Further, the following restrictions apply: Further, the following restrictions apply:
Restrictions to Refinement on Restrictions to Refinement on
object syntax range enumeration size repertoire object syntax range enumeration size repertoire
----------------- ----- ----------- ---- ---------- ----------------- ----- ----------- ---- ----------
INTEGER (1) (2) - - INTEGER (1) (2) - -
Integer32 (1) - - - | Integer32 (1) - - -
Unsigned32 (1) - - - | Unsigned32 (1) - - -
OCTET STRING - - (3) (4) OCTET STRING - - (3) (4)
OBJECT IDENTIFIER - - - - OBJECT IDENTIFIER - - - -
BITS - (2) - - | BITS - (2) - -
IpAddress - - - - IpAddress - - - -
Counter32 - - - - Counter32 - - - -
Counter64 - - - - Counter64 - - - -
Gauge32 (1) - - - Gauge32 (1) - - -
TimeTicks - - - - TimeTicks - - - -
NsapAddress - - - -
where: where:
(1) the range of permitted values may be refined by raising the lower- (1) the range of permitted values may be refined by raising the lower-
bounds, by reducing the upper-bounds, and/or by reducing the bounds, by reducing the upper-bounds, and/or by reducing the
alternative value/range choices; alternative value/range choices;
(2) the enumeration of named-values may be refined by removing one or (2) the enumeration of named-values may be refined by removing one or
more named-values; more named-values (note that for BITS, a refinement may cause the |
enumerations to no longer be contiguous); |
(3) the size in characters of the value may be refined by raising the (3) the size in characters of the value may be refined by raising the
lower-bounds, by reducing the upper-bounds, and/or by reducing the lower-bounds, by reducing the upper-bounds, and/or by reducing the
alternative size choices; or, alternative size choices; or,
(4) the repertoire of characters in the value may be reduced by further (4) the repertoire of characters in the value may be reduced by further
sub-typing. sub-typing.
Otherwise no refinements are possible. Further details on sub-typing | Otherwise no refinements are possible. Further details on sub-typing
are provided in Appendix C. | are provided in Appendix C.
10. Extending an Information Module 10. Extending an Information Module
As experience is gained with a published information module, it may be As experience is gained with a published information module, it may be
desirable to revise that information module. desirable to revise that information module.
To begin, the invocation of the MODULE-IDENTITY macro should be updated To begin, the invocation of the MODULE-IDENTITY macro should be updated
to include information about the revision. Usually, this consists of to include information about the revision. Usually, this consists of
updating the LAST-UPDATED clause and adding a pair of REVISION and updating the LAST-UPDATED clause and adding a pair of REVISION and
DESCRIPTION clauses. However, other existing clauses in the invocation DESCRIPTION clauses. However, other existing clauses in the invocation
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On the other hand, the definition of conceptual rows where the number of On the other hand, the definition of conceptual rows where the number of
columnar objects used as indexes outnumbers the number used to hold columnar objects used as indexes outnumbers the number used to hold
information, should also be avoided. In particular, the splitting of a information, should also be avoided. In particular, the splitting of a
managed object class's attributes into many conceptual tables should not managed object class's attributes into many conceptual tables should not
be used as a way to obtain the same degree of flexibility/complexity as be used as a way to obtain the same degree of flexibility/complexity as
is often found in MIBs with a myriad of optionals. is often found in MIBs with a myriad of optionals.
11.1.1. Mapping to the SYNTAX clause 11.1.1. Mapping to the SYNTAX clause
When mapping to the SYNTAX clause of the OBJECT-TYPE macro: | When mapping to the SYNTAX clause of the OBJECT-TYPE macro:
(1) An object with BOOLEAN syntax becomes a TruthValue [3]. (1) An object with BOOLEAN syntax becomes a TruthValue [3].
(2) An object with INTEGER syntax becomes an Integer32. (2) An object with INTEGER syntax becomes an Integer32.
(3) An object with ENUMERATED syntax becomes an INTEGER with (3) An object with ENUMERATED syntax becomes an INTEGER with
enumerations, taking any of the values given which can be enumerations, taking any of the values given which can be
represented with an Integer32. represented with an Integer32.
(4) An object with BIT STRING syntax having enumerations becomes a BITS + (4) An object with BIT STRING syntax having enumerations becomes a BITS
construct. + construct.
(5) + (5) An object with BIT STRING syntax but no enumerations becomes an
An object with BIT STRING syntax but no enumerations becomes an
OCTET STRING. OCTET STRING.
(6) An object with a character string syntax becomes either an OCTET (6) An object with a character string syntax becomes either an OCTET
STRING, or a DisplayString [3], depending on the repertoire of the STRING, or a DisplayString [3], depending on the repertoire of the
character string. character string.
(7) A non-tabular object with a complex syntax, such as REAL or (7) A non-tabular object with a complex syntax, such as REAL or
EXTERNAL, must be decomposed, usually into an OCTET STRING (if EXTERNAL, must be decomposed, usually into an OCTET STRING (if
sensible). As a rule, any object with a complicated syntax should sensible). As a rule, any object with a complicated syntax should
be avoided. be avoided.
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single-quotes or removed). single-quotes or removed).
11.3.3. Mapping to the REFERENCE clause 11.3.3. Mapping to the REFERENCE clause
This is straight-forward: simply include a textual reference to the This is straight-forward: simply include a textual reference to the
notification being mapped, the document which defines the notification, notification being mapped, the document which defines the notification,
and perhaps a page number in the document. and perhaps a page number in the document.
12. Appendix B: UTC Time Format 12. Appendix B: UTC Time Format
Several clauses defined in this document use the UTC Time format: | Several clauses defined in this document use the UTC Time format:
YYMMDDHHMMZ | YYMMDDHHMMZ
where: YY - last two digits of year | where: YY - last two digits of year
MM - month (01 through 12) | MM - month (01 through 12)
DD - day of month (01 through 31) | DD - day of month (01 through 31)
HH - hours (00 through 23) | HH - hours (00 through 23)
MM - minutes (00 through 59) | MM - minutes (00 through 59)
Z - the character "Z" denotes Greenwich Mean Time (GMT). | Z - the character "Z" denotes Greenwich Mean Time (GMT).
For example, "9502192015Z" represents 8:15pm GMT on 19 February 1995. | For example, "9502192015Z" represents 8:15pm GMT on 19 February 1995.
13. Appendix C: Detailed Sub-typing Rules 13. Appendix C: Detailed Sub-typing Rules
13.1. Syntax Rules 13.1. Syntax Rules
The syntax rules for sub-typing are given below. Note that while this + 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 + 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 + allowed in ASN.1, and a number of ASN.1 constructs are not allowed by
this syntax. + this syntax.
<integerSubType> + <integerSubType>
::= <empty> + ::= <empty>
| "(" <range> ["|" <range>]... ")" + | "(" <range> ["|" <range>]... ")"
<octetStringSubType> + <octetStringSubType>
::= <empty> + ::= <empty>
| "(" "SIZE" "(" <range> ["|" <range>]... ")" ")" + | "(" "SIZE" "(" <range> ["|" <range>]... ")" ")"
<range> + <range>
::= <value> + ::= <value>
| <value> ".." <value> + | <value> ".." <value>
<value> + <value>
::= "-" <number> + ::= "-" <number>
| <number> + | <number>
| <hexString> + | <hexString>
| <binString> + | <binString>
where: + where:
<empty> is the empty string + <empty> is the empty string
<number> is a non-negative integer + <number> is a non-negative integer
<hexString> is a hexadecimal string (i.e. 'xxxx'H) + <hexString> is a hexadecimal string (i.e. 'xxxx'H)
<binString> is a binary string (i.e. 'xxxx'B) + <binString> is a binary string (i.e. 'xxxx'B)
<range> is further restricted as follows: + <range> is further restricted as follows:
- any <value> used in a SIZE clause must be non-negative. + - any <value> used in a SIZE clause must be non-negative.
- when a pair of values is specified, the first value + - when a pair of values is specified, the first value
must be less than the second value. + must be less than the second value.
- when multiple ranges are specified, the ranges may + - when multiple ranges are specified, the ranges may
not overlap but may touch. For example, (1..4 | 4..9) + not overlap but may touch. For example, (1..4 | 4..9)
is invalid, and (1..4 | 5..9) is valid. + is invalid, and (1..4 | 5..9) is valid.
- the ranges must be a subset of the maximum range of the + - the ranges must be a subset of the maximum range of the
base type. + base type.
13.2. Examples + 13.2. Examples
Some examples of legal sub-typing: + Some examples of legal sub-typing:
Integer32 (-20..100) + Integer32 (-20..100)
Integer32 (0..100 | 300..500) + Integer32 (0..100 | 300..500)
Integer32 (300..500 | 0..100) + Integer32 (300..500 | 0..100)
Integer32 (0 | 2 | 4 | 6 | 8 | 10) + Integer32 (0 | 2 | 4 | 6 | 8 | 10)
OCTET STRING (SIZE(0..100)) + OCTET STRING (SIZE(0..100))
OCTET STRING (SIZE(0..100 | 300..500)) + OCTET STRING (SIZE(0..100 | 300..500))
OCTET STRING (SIZE(0 | 2 | 4 | 6 | 8 | 10)) + OCTET STRING (SIZE(0 | 2 | 4 | 6 | 8 | 10))
Some examples of illegal sub-typing: + Some examples of illegal sub-typing:
Integer32 (150..100) -- first greater than second + Integer32 (150..100) -- first greater than second
Integer32 (0..100 | 50..500) -- ranges overlap + Integer32 (0..100 | 50..500) -- ranges overlap
Integer32 (0 | 2 | 0 ) -- value duplicated + Integer32 (0 | 2 | 0 ) -- value duplicated
Integer32 (MIN..-1 | 1..MAX) -- MIN and MAX not allowed + Integer32 (MIN..-1 | 1..MAX) -- MIN and MAX not allowed
Integer32 ((SIZE (0..34)) -- must not use SIZE + Integer32 ((SIZE (0..34)) -- must not use SIZE
OCTET STRING (0..100) -- must use SIZE + OCTET STRING (0..100) -- must use SIZE
OCTET STRING (SIZE(-10..100)) -- negative SIZE + OCTET STRING (SIZE(-10..100)) -- negative SIZE
13.3. Rules for Textual Conventions + 13.3. Rules for Textual Conventions
Sub-typing of Textual Conventions (see [3]) is allowed but must be + Sub-typing of Textual Conventions (see [3]) is allowed but must be
valid. In particular, each range specified for the textual convention + valid. In particular, each range specified for the textual convention
must be a subset of a range specified for the base type. For example, + must be a subset of a range specified for the base type. For example,
Tc1 ::= INTEGER (1..10 | 11..20) + Tc1 ::= INTEGER (1..10 | 11..20)
Tc2 ::= Tc1 (2..10 | 12..15) -- is valid + Tc2 ::= Tc1 (2..10 | 12..15) -- is valid
Tc3 ::= Tc1 (8..12) -- is invalid + Tc3 ::= Tc1 (4..8) -- is valid |
Tc4 ::= Tc1 (8..12) -- is invalid |
14. Acknowledgements + 14. Acknowledgements
The authors wish to acknowledge the contributions of the SNMPv2 Working + The authors wish to acknowledge the contributions of the SNMPv2 Working
Group in general. In particular, the following individuals + Group in general. In particular, the following individuals
Dave Arneson (Cabletron), + Dave Arneson (Cabletron),
Uri Blumenthal (IBM), + Uri Blumenthal (IBM),
Doug Book (Chipcom), + Doug Book (Chipcom),
Maria Greene (Ascom Timeplex), + Maria Greene (Ascom Timeplex),
Deirdre Kostik (Bellcore), + Deirdre Kostik (Bellcore),
Dave Harrington (Cabletron), + Dave Harrington (Cabletron),
Jeff Johnson (Cisco Systems), + Jeff Johnson (Cisco Systems),
Brian O'Keefe (Hewlett Packard), + Brian O'Keefe (Hewlett Packard),
Dave Perkins (Bay Networks), + Dave Perkins (Bay Networks),
Randy Presuhn (Peer Networks), + Randy Presuhn (Peer Networks),
Shawn Routhier (Epilogue), + Shawn Routhier (Epilogue),
Bob Stewart (Cisco Systems), + Bob Stewart (Cisco Systems),
Kaj Tesink (Bellcore). + Kaj Tesink (Bellcore).
deserve special thanks for their contributions. + deserve special thanks for their contributions.
15. References 15. References
[1] Information processing systems - Open Systems Interconnection - [1] Information processing systems - Open Systems Interconnection -
Specification of Abstract Syntax Notation One (ASN.1), Specification of Abstract Syntax Notation One (ASN.1),
International Organization for Standardization. International International Organization for Standardization. International
Standard 8824, (December, 1987). Standard 8824, (December, 1987).
[2] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., [2] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
"Conformance Statements for Version 2 of the the Simple Network "Conformance Statements for Version 2 of the the Simple Network
Management Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Management Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc.,
Cisco Systems, Dover Beach Consulting, Inc., Carnegie Mellon Cisco Systems, Dover Beach Consulting, Inc., Carnegie Mellon
University, November 1994. University, May 1995. |
[3] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Textual [3] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Textual
Conventions for Version 2 of the the Simple Network Management Conventions for Version 2 of the the Simple Network Management
Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco
Systems, Dover Beach Consulting, Inc., Carnegie Mellon University, Systems, Dover Beach Consulting, Inc., Carnegie Mellon University, |
November 1994. May 1995. |
[4] Information processing systems - Open Systems Interconnection - [4] Information processing systems - Open Systems Interconnection -
Specification of Basic Encoding Rules for Abstract Syntax Notation Specification of Basic Encoding Rules for Abstract Syntax Notation
One (ASN.1), International Organization for Standardization. One (ASN.1), International Organization for Standardization.
International Standard 8825, (December, 1987). International Standard 8825, (December, 1987).
[5] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Management [5] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Management
Information Base for Version 2 of the Simple Network Management Information Base for Version 2 of the Simple Network Management
Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco
Systems, Dover Beach Consulting, Inc., Carnegie Mellon University, Systems, Dover Beach Consulting, Inc., Carnegie Mellon University, |
November 1994. May 1995. |
[6] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Protocol [6] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., "Protocol
Operations for Version 2 of the Simple Network Management Protocol Operations for Version 2 of the Simple Network Management Protocol
(SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco Systems, (SNMPv2)", Internet Draft, SNMP Research, Inc., Cisco Systems,
Dover Beach Consulting, Inc., Carnegie Mellon University, November Dover Beach Consulting, Inc., Carnegie Mellon University, May 1995. |
1994.
[7] Case, J., Galvin, J., McCloghrie, K., Rose, M., and Waldbusser, S., | [7] Case, J., Galvin, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
"Party MIB for Version 2 of the Simple Network Management Protocol "Party MIB for Version 2 of the Simple Network Management Protocol
(SNMPv2)", Internet Draft, SNMP Research, Inc., Trusted Information | (SNMPv2)", Internet Draft, SNMP Research, Inc., Trusted Information
Systems, Cisco Systems, Dover Beach Consulting, Inc., Carnegie | Systems, Cisco Systems, Dover Beach Consulting, Inc., Carnegie
Mellon University, | Mellon University, May 1995. |
November 1994.
[8] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., + [8] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
"Coexistence between Version 1 and Version 2 of the Internet- + "Coexistence between Version 1 and Version 2 of the Internet-
standard Network Management Framework", Internet Draft, SNMP + standard Network Management Framework", Internet Draft, SNMP
Research, Inc., Cisco Systems, Dover Beach Consulting, Inc., + Research, Inc., Cisco Systems, Dover Beach Consulting, Inc.,
Carnegie Mellon University, November 1994. + Carnegie Mellon University, May 1995. |
[9] Case, J., McCloghrie, K., Rose, M., and Waldbusser, S., + [9] Reynolds, J., and Postel, J., "Assigned Numbers", RFC 1700, ISI, |
"Conformance Statements for Version 2 of the the Simple Network + November 1994. |
Management Protocol (SNMPv2)", Internet Draft, SNMP Research, Inc., +
Cisco Systems, Dover Beach Consulting, Inc., Carnegie Mellon +
University, November 1994. +
16. Security Considerations + 16. Security Considerations -
Security issues are not discussed in this memo. Security issues are not discussed in this memo.
17. Authors' Addresses 17. Authors' Addresses
Jeffrey D. Case Jeffrey D. Case
SNMP Research, Inc. SNMP Research, Inc.
3001 Kimberlin Heights Rd. 3001 Kimberlin Heights Rd.
Knoxville, TN 37920-9716 Knoxville, TN 37920-9716
US US
skipping to change at page 54, line 9 skipping to change at page 55, line 9
Pittsburgh, PA 15213 Pittsburgh, PA 15213
US US
Phone: +1 412 268 6628 Phone: +1 412 268 6628
Email: waldbusser@cmu.edu Email: waldbusser@cmu.edu
Table of Contents Table of Contents
1 Introduction .................................................... 3 1 Introduction .................................................... 3
1.1 A Note on Terminology ......................................... 3 1.1 A Note on Terminology ......................................... 3
1.2 Change Log .................................................... 4
2 Definitions ..................................................... 5 2 Definitions ..................................................... 5
3.1 The MODULE-IDENTITY macro ..................................... 6 3.1 The MODULE-IDENTITY macro ..................................... 6
3.2 Object Names and Syntaxes ..................................... 8 3.2 Object Names and Syntaxes ..................................... 8
3.3 The OBJECT-TYPE macro ......................................... 11 3.3 The OBJECT-TYPE macro ......................................... 11
3.5 The NOTIFICATION-TYPE macro ................................... 13 3.5 The NOTIFICATION-TYPE macro ................................... 13
3.6 Administrative Identifiers .................................... 13 3.6 Administrative Identifiers .................................... 13
3 Information Modules ............................................. 14 3 Information Modules ............................................. 14
3.1 Macro Invocation .............................................. 14 3.1 Macro Invocation .............................................. 15
3.1.1 Textual Clauses ............................................. 15 3.1.1 Textual Clauses ............................................. 15
3.2 IMPORTing Symbols ............................................. 15 3.2 IMPORTing Symbols ............................................. 16
4 Naming Hierarchy ................................................ 17 3.3 Exporting Symbols ............................................. 16
5 Mapping of the MODULE-IDENTITY macro ............................ 18 3.4 ASN.1 Comments ................................................ 16
5.1 Mapping of the LAST-UPDATED clause ............................ 18 3.5 OBJECT IDENTIFIER values ...................................... 17
5.2 Mapping of the ORGANIZATION clause ............................ 18 4 Naming Hierarchy ................................................ 18
5.3 Mapping of the CONTACT-INFO clause ............................ 18 5 Mapping of the MODULE-IDENTITY macro ............................ 19
5.4 Mapping of the DESCRIPTION clause ............................. 18 5.1 Mapping of the LAST-UPDATED clause ............................ 19
5.5 Mapping of the REVISION clause ................................ 18 5.2 Mapping of the ORGANIZATION clause ............................ 19
5.6 Mapping of the DESCRIPTION clause ............................. 19 5.3 Mapping of the CONTACT-INFO clause ............................ 19
5.7 Mapping of the MODULE-IDENTITY value .......................... 19 5.4 Mapping of the DESCRIPTION clause ............................. 19
5.8 Usage Example ................................................. 20 5.5 Mapping of the REVISION clause ................................ 20
6 Mapping of the OBJECT-IDENTITY macro ............................ 21 5.5.1 Mapping of the DESCRIPTION sub-clause ....................... 20
6.1 Mapping of the STATUS clause .................................. 21 5.6 Mapping of the MODULE-IDENTITY value .......................... 20
6.2 Mapping of the DESCRIPTION clause ............................. 21 5.7 Usage Example ................................................. 21
6.3 Mapping of the REFERENCE clause ............................... 21 6 Mapping of the OBJECT-IDENTITY macro ............................ 22
6.4 Mapping of the OBJECT-IDENTITY value .......................... 21 6.1 Mapping of the STATUS clause .................................. 22
6.5 Usage Example ................................................. 22 6.2 Mapping of the DESCRIPTION clause ............................. 22
7 Mapping of the OBJECT-TYPE macro ................................ 23 6.3 Mapping of the REFERENCE clause ............................... 22
7.1 Mapping of the SYNTAX clause .................................. 23 6.4 Mapping of the OBJECT-IDENTITY value .......................... 22
7.1.1 Integer32 and INTEGER ....................................... 23 6.5 Usage Example ................................................. 23
7.1.2 OCTET STRING ................................................ 24 7 Mapping of the OBJECT-TYPE macro ................................ 24
7.1.3 OBJECT IDENTIFIER ........................................... 24 7.1 Mapping of the SYNTAX clause .................................. 24
7.1.4 The BITS construct .......................................... 24 7.1.1 Integer32 and INTEGER ....................................... 24
7.1.5 IpAddress ................................................... 24 7.1.2 OCTET STRING ................................................ 25
7.1.6 Counter32 ................................................... 25 7.1.3 OBJECT IDENTIFIER ........................................... 25
7.1.7 Gauge32 ..................................................... 25 7.1.4 The BITS construct .......................................... 25
7.1.8 TimeTicks ................................................... 25 7.1.5 IpAddress ................................................... 26
7.1.9 Opaque ...................................................... 26 7.1.6 Counter32 ................................................... 26
7.1.10 NsapAddress ................................................ 26 7.1.7 Gauge32 ..................................................... 26
7.1.11 Counter64 .................................................. 26 7.1.8 TimeTicks ................................................... 27
7.1.9 Opaque ...................................................... 27
7.1.12 Unsigned32 ................................................. 27 7.1.10 Counter64 .................................................. 27
7.2 Mapping of the UNITS clause ................................... 27 7.1.11 Unsigned32 ................................................. 28
7.3 Mapping of the MAX-ACCESS clause .............................. 27 7.1.12 Conceptual Tables .......................................... 28
7.4 Mapping of the STATUS clause .................................. 28 7.1.12.1 Creation and Deletion of Conceptual Rows ................. 29
7.5 Mapping of the DESCRIPTION clause ............................. 28 7.2 Mapping of the UNITS clause ................................... 29
7.6 Mapping of the REFERENCE clause ............................... 28 7.3 Mapping of the MAX-ACCESS clause .............................. 29
7.7 Mapping of the INDEX clause ................................... 29 7.4 Mapping of the STATUS clause .................................. 30
7.7.1 Creation and Deletion of Conceptual Rows .................... 31 7.5 Mapping of the DESCRIPTION clause ............................. 30
7.8 Mapping of the AUGMENTS clause ................................ 31 7.6 Mapping of the REFERENCE clause ............................... 30
7.8.1 Relation between INDEX and AUGMENTS clauses ................. 32 7.7 Mapping of the INDEX clause ................................... 30
7.8 Mapping of the AUGMENTS clause ................................ 32
7.8.1 Relation between INDEX and AUGMENTS clauses ................. 33
7.9 Mapping of the DEFVAL clause .................................. 33 7.9 Mapping of the DEFVAL clause .................................. 33
7.10 Mapping of the OBJECT-TYPE value ............................. 34 7.10 Mapping of the OBJECT-TYPE value ............................. 34
7.11 Usage Example ................................................ 35 7.11 Usage Example ................................................ 36
8 Mapping of the NOTIFICATION-TYPE macro .......................... 37 8 Mapping of the NOTIFICATION-TYPE macro .......................... 38
8.1 Mapping of the OBJECTS clause ................................. 37 8.1 Mapping of the OBJECTS clause ................................. 38
8.2 Mapping of the STATUS clause .................................. 37 8.2 Mapping of the STATUS clause .................................. 38
8.3 Mapping of the DESCRIPTION clause ............................. 37 8.3 Mapping of the DESCRIPTION clause ............................. 38
8.4 Mapping of the REFERENCE clause ............................... 37 8.4 Mapping of the REFERENCE clause ............................... 39
8.5 Mapping of the NOTIFICATION-TYPE value ........................ 38 8.5 Mapping of the NOTIFICATION-TYPE value ........................ 39
8.6 Usage Example ................................................. 39 8.6 Usage Example ................................................. 40
9 Refined Syntax .................................................. 40 9 Refined Syntax .................................................. 41
10 Extending an Information Module ................................ 41 10 Extending an Information Module ................................ 42
10.1 Object Assignments ........................................... 41 10.1 Object Assignments ........................................... 42
10.2 Object Definitions ........................................... 41 10.2 Object Definitions ........................................... 42
10.3 Notification Definitions ..................................... 42 10.3 Notification Definitions ..................................... 43
11 Appendix A: de-OSIfying a MIB module ........................... 43 11 Appendix A: de-OSIfying a MIB module ........................... 44
11.1 Managed Object Mapping ....................................... 43 11.1 Managed Object Mapping ....................................... 44
11.1.1 Mapping to the SYNTAX clause ............................... 44 11.1.1 Mapping to the SYNTAX clause ............................... 45
11.1.2 Mapping to the UNITS clause ................................ 45 11.1.2 Mapping to the UNITS clause ................................ 46
11.1.3 Mapping to the MAX-ACCESS clause ........................... 45 11.1.3 Mapping to the MAX-ACCESS clause ........................... 46
11.1.4 Mapping to the STATUS clause ............................... 45 11.1.4 Mapping to the STATUS clause ............................... 46
11.1.5 Mapping to the DESCRIPTION clause .......................... 45 11.1.5 Mapping to the DESCRIPTION clause .......................... 46
11.1.6 Mapping to the REFERENCE clause ............................ 45 11.1.6 Mapping to the REFERENCE clause ............................ 46
11.1.7 Mapping to the INDEX clause ................................ 45 11.1.7 Mapping to the INDEX clause ................................ 46
11.1.8 Mapping to the DEFVAL clause ............................... 45 11.1.8 Mapping to the DEFVAL clause ............................... 46
11.2 Action Mapping ............................................... 46 11.2 Action Mapping ............................................... 47
11.2.1 Mapping to the SYNTAX clause ............................... 46 11.2.1 Mapping to the SYNTAX clause ............................... 47
11.2.2 Mapping to the MAX-ACCESS clause ........................... 46 11.2.2 Mapping to the MAX-ACCESS clause ........................... 47
11.2.3 Mapping to the STATUS clause ............................... 46 11.2.3 Mapping to the STATUS clause ............................... 47
11.2.4 Mapping to the DESCRIPTION clause .......................... 46 11.2.4 Mapping to the DESCRIPTION clause .......................... 47
11.2.5 Mapping to the REFERENCE clause ............................ 46 11.2.5 Mapping to the REFERENCE clause ............................ 47
11.3 Event Mapping ................................................ 46 11.3 Event Mapping ................................................ 47
11.3.1 Mapping to the STATUS clause ............................... 47 11.3.1 Mapping to the STATUS clause ............................... 48
11.3.2 Mapping to the DESCRIPTION clause .......................... 47
11.3.3 Mapping to the REFERENCE clause ............................ 47
12 Appendix B: UTC Time Format .................................... 48 11.3.2 Mapping to the DESCRIPTION clause .......................... 48
13 Appendix C: Detailed Sub-typing Rules .......................... 49 11.3.3 Mapping to the REFERENCE clause ............................ 48
13.1 Syntax Rules ................................................. 49 12 Appendix B: UTC Time Format .................................... 49
13.2 Examples ..................................................... 50 13 Appendix C: Detailed Sub-typing Rules .......................... 50
13.3 Rules for Textual Conventions ................................ 50 13.1 Syntax Rules ................................................. 50
14 Acknowledgements ............................................... 51 13.2 Examples ..................................................... 51
15 References ..................................................... 51 13.3 Rules for Textual Conventions ................................ 51
16 Security Considerations ........................................ 53 14 Acknowledgements ............................................... 52
17 Authors' Addresses ............................................. 53 15 References ..................................................... 52
16 Security Considerations ........................................ 54
17 Authors' Addresses ............................................. 54
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