SNMP/SMI研究总结

这些日子因为要做一个模型适配的东西，一直在看SNMP相关的RFC，总结些东西，放到这里。

SMIv2包括：

RFC2578 SMIv2（对syntax的说明：The data structure must be one of the following: a base type, the BITS construct？？（这个不是太懂，有了解的请赐教）, or a textual 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 [RFC2579].）

RFC2579 Textual Conventions for SMIv2（When designing a MIB module, it is often useful to define new types similar to those defined in the SMI. In comparison to a type defined in the SMI, each of these new types has a different name, a similar syntax, but a more precise semantics. These newly defined types are termed textual conventions, and are used for the convenience of humans reading the MIB module. It is the purpose of this document to define the initial set of textual conventions available to all MIB modules.）

RFC2580 SMIv2 Conformance Statements for SMIv（It may be useful to define the acceptable lower-bounds of implementation, along with the actual level of implementation achieved. It is the purpose of this document to define the notation used for these purposes.）

表格 1 SMI发展概览（SMI第一版）

SMI首次定义	1988.8	1065
SMI修订	1990.5	1155
精确MIB格式的定义	1991.3	1212
陷阱的定义	1991.3	1215

表格 2 MIB发展概览

MIB-1首次定义	1988.8	1066
MIB-1修改	1990.5	1156
MIB-2引入	1990.5	1158
MIB-2修改	1991.3	1213

表格 3 SNMPv2 RFC发展历程(SMIv2)

	Obsolete	Obsolete	Current
SNMPv2 SMI	1442	1902（1996）	2578（1999）SMIv2
SNMPv2 TC	1443	1903	2579 SMIv2-TC
SNMPv2 CONF	1444	1904	2580 SMIv2-CONF

SNMPv2（狭义）与SMIv2的联系，独立

MIB中的类型和宏：

RFC2578（Obsoletes: 1902 D. Perkin）	数据类型	-- 3 built-in ASN.1 types: INTEGER, OCTET STRING, OBJECT IDENTIFIER -- 8 application-defined types: Integer32, IpAddress, Counter32, -- Gauge32, Unsigned32, TimeTicks, Opaque, and Counter64
RFC2578（Obsoletes: 1902 D. Perkin）	宏	MODULE-IDENTITY MACROOBJECT-IDENTITY MACRO OBJECT-TYPE MACRO NOTIFICATION-TYPE MACRO
RFC2579（Obsoletes: 1903）	数据类型	DisplayString（totalSNMPp86） PhysAddress MacAddress TruthValue TestAndIncr AutonomousType InstancePointer VariablePointer RowStatus RowPointe TimeStamp TimeInterval DateAndTime StorageType TDomain TAddress
RFC2579（Obsoletes: 1903）	宏	TEXTUAL-CONVENTION
RFC2580（Obsoletes: 1904）	数据类型
RFC2580（Obsoletes: 1904）	宏	OBJECT-GROUP NOTIFICATION-GROUP MODULE-COMPLIANCE ANENT-CAPABILITIE
		??IMPORTS ObjectName, NotificationName, ObjectSyntax FROM SNMPv2-SMI

表格 4 MAX-ACCESS字段取值说明

not-accessible
accessible-for notify
read-only
read-write
read-creat

表格 5 STATUS字段取值说明

current
deprecated
obsolete

Reserved Keywords（2578）

The following are reserved keywords which must not be used as

descriptors or module names:

ABSENT ACCESS AGENT-CAPABILITIES ANY APPLICATION AUGMENTS BEGIN

BIT BITS BOOLEAN BY CHOICE COMPONENT COMPONENTS CONTACT-INFO

CREATION-REQUIRES Counter32 Counter64 DEFAULT DEFINED

DEFINITIONS DEFVAL DESCRIPTION DISPLAY-HINT END ENUMERATED

ENTERPRISE EXPLICIT EXPORTS EXTERNAL FALSE FROM GROUP Gauge32

IDENTIFIER IMPLICIT IMPLIED IMPORTS INCLUDES INDEX INTEGER

Integer32 IpAddress LAST-UPDATED MANDATORY-GROUPS MAX MAX-ACCESS

MIN MIN-ACCESS MINUS-INFINITY MODULE MODULE-COMPLIANCE MODULE-

IDENTITY NOTIFICATION-GROUP NOTIFICATION-TYPE NOTIFICATIONS NULL

OBJECT OBJECT-GROUP OBJECT-IDENTITY OBJECT-TYPE OBJECTS OCTET OF

OPTIONAL ORGANIZATION Opaque PLUS-INFINITY PRESENT PRIVATE

PRODUCT-RELEASE REAL REFERENCE REVISION SEQUENCE SET SIZE STATUS

STRING SUPPORTS SYNTAX TAGS TEXTUAL-CONVENTION TRAP-TYPE TRUE

TimeTicks UNITS UNIVERSAL Unsigned32 VARIABLES VARIATION WITH

WRITE-SYNTAX

OBJECT IDENTIFIER解析：

mib-2 OBJECT IDENTIFIER ::= { mgmt 1 } -- mgmtOID=1.3.6.1.2

system OBJECT IDENTIFIER ::= { mib-2 1 } --表示方法1

system OBJECT IDENTIFIER ::= { mgmt mib-2(1) system(1) } --表示方法2

system OBJECT IDENTIFIER ::= { mgmt mib-2(1) 1 } --表示方法3

system OBJECT IDENTIFIER ::= 1.3.6.1.2.1.1 --表示方法4

每个类都有自己的OID?（只有TC宏没有。）

Syntax ::= -- Must be one of the following:

-- a base type (or its refinement),

-- a textual convention (or its refinement), or

-- a BITS pseudo-type？？