Quartz 4

SMI - Modelo de información en Internet

18 min read

2GRS-GAR-GG-SMI

Modelo de información en Internet Gestión de Redes

Índice

  • Estructura y documentos
  • SMI: Versiones y definiciones
  • SMI: Macros
  • MIB: Ejemplos de declaraciones

Objetivo

  • Leer e interpretar documentos MIBs
  • Es necesario conocer:
    • Sintaxis ASN.1 – trabajo personal
    • Documentación con las bases: SMI – en clase

Ejemplo (representaciones equivalentes de un mismo OID):

  • 1.3.6.1.2.1.4.1

  • IP-MIB::ipForwarding

  • SNMPv2-MIB::ipForwarding

  • Iso.org.dod.internet.mgmt.mib2.ip.ipForwarding

  • SMI – Structure of Management Information

  • MIB – Management Information Base

Documentos – Estructura

  • SMI: Structure of Management Information — RFC1155
    • Estructura del árbol de gestión.
    • Declaraciones de tipos utilizados en las MIBs.
    • Declaración de la macro OBJECT TYPE para definir objetos.
  • Concise MIB Definitions — RFC1212
    • Ampliación de la macro de OBJECT TYPE.
  • SMIv2 — RFC2578
  • Textual Conventions for SMIv2 — RFC2579
  • Conformance Statements for SMIv2 — RFC2580
  • MIB estándar en RFC1156 y MIB-2 estándar en RFC1213

Documentos – MIBs

Ejemplos de estructura de MIBs

MIBs-II ( RFC1213):

  • system
  • interfaces
  • at
  • ip
  • icmp
  • tcp
  • udp
  • egp
  • snmp

HostResources:

  • hrSystem
  • hrStorage
  • hrDevice
  • hrProcessor
  • hrNetwork
  • hrPrinter
  • hrDisk
  • hrPartition
  • hrFS
  • hrSWRun
  • hrSWRunPerf
  • hrSWInstalled

Módulo SMI

RFC1155-SMI DEFINITIONS ::= BEGIN

EXPORTS -- EVERYTHING
internet, directory, mgmt,
experimental, private, enterprises,
OBJECT-TYPE, ObjectName, ObjectSyntax,
SimpleSyntax, ApplicationSyntax,
NetworkAddress, IpAddress,
Counter, Gauge, TimeTicks, Opaque;
END

SMI – Estructura del árbol de gestión

Define la estructura del árbol de MIB en ASN.1.

Nota: uit-t = 0, iso = 1, uit-t/iso = 2

internet OBJECT IDENTIFIER ::= { iso org ( 3) dod ( 6) 1 }
directory OBJECT IDENTIFIER ::= { internet 1 }
mgmt OBJECT IDENTIFIER ::= { internet 2 }
experimental OBJECT IDENTIFIER ::= { internet 3 }
private OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { private 1 }

http://tools.ietf.org/html/rfc1155

SMIv2 – Estructura del árbol de gestión

SNMPv2-SMI DEFINITIONS ::= BEGIN
org OBJECT IDENTIFIER ::= { iso 3 } -- "iso" = 1
dod OBJECT IDENTIFIER ::= { org 6 }
internet OBJECT IDENTIFIER ::= { dod 1 }
directory OBJECT IDENTIFIER ::= { internet 1 }
mgmt OBJECT IDENTIFIER ::= { internet 2 }
mib-2 OBJECT IDENTIFIER ::= { mgmt 1 }
transmission OBJECT IDENTIFIER ::= { mib-2 10 }
experimental OBJECT IDENTIFIER ::= { internet 3 }
private OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { private 1 }
security OBJECT IDENTIFIER ::= { internet 5 }
snmpV2 OBJECT IDENTIFIER ::= { internet 6 }

http://tools.ietf.org/html/rfc2578

SMIv2 (Domains and time)

-- transport domains
snmpDomains OBJECT IDENTIFIER ::= { snmpV2 1 }
-- transport proxies
snmpProxys OBJECT IDENTIFIER ::= { snmpV2 2 }
-- module identities
snmpModules OBJECT IDENTIFIER ::= { snmpV2 3 }
--Extended UTCTime
ExtUTCTime ::= OCTET STRING ( SIZE ( 11 | 13))
-- format is YYMMDDHHMMZ or YYYYMMDDHHMMZ

Tipos definidos

Está permitido usar los siguientes tipos universales:

  • Primitivos: INTEGER, OCTET STRING, NULL, OBJECT IDENTIFIER.
  • Construidos: SEQUENCE y SECUENCE OF.

Los enumerados se declaran como enteros y no se utiliza el valor 0.

Tipos definidos ( cont)

  • Tipo predefinidos:
    • NetworkAddress: CHOICE que permite seleccionar varios formatos de direcciones. Actualmente sólo IpAddress.
    • IpAddress: Dirección IP versión 4.
    • Counter: Entero no negativo de 32 bits que puede ser incrementado, pero no decrementado. Cuando alcanza el valor máximo comienza por 0. Como alternativa se puede utilizar un latch Counter.
    • Gauge: Entero no negativo de 32 bits que puede ser incrementado o decrementado. Cuando alcanza el valor máximo permanece con ese valor hasta que se pone a cero.
    • TimeTicks: Entero no negativo que cuenta tiempo en centésimas de segundo ( tiempo relativo).
    • Opaque: Datos arbitrarios codificados como OCTET STRING.

Declaración de los tipos definidos

-- application-wide types
NetworkAddress ::= CHOICE {internet IpAddress}
IpAddress ::= [APPLICATION 0] IMPLICIT OCTET STRING ( SIZE ( 4))
Counter ::= [APPLICATION 1] IMPLICIT INTEGER ( 0..4294967295)
Gauge ::= [APPLICATION 2] IMPLICIT INTEGER ( 0..4294967295)
TimeTicks ::= [APPLICATION 3] IMPLICIT INTEGER ( 0..4294967295)
Opaque ::= [APPLICATION 4] IMPLICIT OCTET STRING

http://tools.ietf.org/html/rfc1155

SMIv2:Syntax

ObjectName ::= OBJECT IDENTIFIER
NotificationName ::= OBJECT IDENTIFIER
ObjectSyntax ::= CHOICE {
simple SimpleSyntax,
application-wide ApplicationSyntax
}
SimpleSyntax ::= CHOICE {
integer-value INTEGER (-2147483648..2147483647),
string-value OCTET STRING ( SIZE ( 0..65535)),
objectID-value OBJECT IDENTIFIER
}
Integer32 ::= INTEGER (-2147483648..2147483647)

http://tools.ietf.org/html/rfc2578

SMIv2:Syntax ( cont)

ApplicationSyntax ::= CHOICE {
ipAddress-value IpAddress,
counter-value Counter32,
timeticks-value TimeTicks,
arbitrary-value Opaque,
big-counter-value Counter64,
unsigned-integer-value Unsigned32 -- includes Gauge32 }
IpAddress ::= [APPLICATION 0] IMPLICIT OCTET STRING ( SIZE ( 4))
Counter32 ::= [APPLICATION 1] IMPLICIT INTEGER ( 0..4294967295)
Gauge32 ::= [APPLICATION 2] IMPLICIT INTEGER ( 0..4294967295)
Unsigned32 ::= [APPLICATION 3] IMPLICIT INTEGER ( 0..4294967295)
TimeTicks ::= [APPLICATION 4] IMPLICIT INTEGER ( 0..4294967295)
Opaque ::= [APPLICATION 5] IMPLICIT OCTET STRING
Counter64 ::= [APPLICATION 6] IMPLICIT INTEGER ( 0..18446744073709551615)

http://tools.ietf.org/html/rfc2578

SMIv2:zeroDotzero

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

http://tools.ietf.org/html/rfc2578

Declaración de objetos

Utiliza la macro de definición de objetos ( originalmente definida en SMI RFC1155 y ampliada en Concise MIB Definitions RFC1212):

IMPORTS ObjectName,ObjectSyntax FROM RFC1155-SMI
DisplayString FROM RFC1158-MIB;

OBJECT-TYPE MACRO ::=
BEGIN
END

IndexSyntax ::= CHOICE {
number INTEGER ( 0..MAX),
string OCTET STRING,
object OBJECT IDENTIFIER,
address NetworkAddress,
ipAddress IpAddress
}
DisplayString OCTET STRING

Declaración de objetos: macro OBJECT TYPE

OBJECT-TYPE MACRO ::=
BEGIN

TYPE NOTATION ::=
"SYNTAX" type ( ObjectSyntax)
"ACCESS" Access
"STATUS" Status
DescrPart
ReferPart
IndexPart
DefValPart
VALUE NOTATION ::= value ( VALUE ObjectName)
Access ::= "read-only" | "read-write" | "write-only" | "not-accessible"
Status ::= "mandatory" | "optional" | "obsolete" | "deprecated"
DescrPart ::= "DESCRIPTION" value ( description DisplayString) | empty
ReferPart ::= "REFERENCE" value ( reference DisplayString) | empty
IndexPart ::= "INDEX" "{" IndexTypes "}" | empty
IndexTypes ::= IndexType | IndexTypes "," IndexType
IndexType ::= value ( indexobject ObjectName) | type ( indextype) --IndexSyntax
DefValPart ::= "DEFVAL" "{" value ( defvalue ObjectSyntax) "}" | empty
END

http://tools.ietf.org/html/rfc1212

Declaración de objetos ( cont)

ObjectName ::= OBJECT IDENTIFIER
ObjectSyntax ::= CHOICE {simple SimpleSyntax,
application-wide ApplicationSyntax}
SimpleSyntax ::= CHOICE {number INTEGER, string OCTET STRING,
object OBJECT IDENTIFIER, empty NULL}
ApplicationSyntax ::= CHOICE {address NetworkAddress, counter Counter,
gauge Gauge, ticks TimeTicks, arbitrary Opaque }

http://tools.ietf.org/html/rfc1155

Declaración de objetos ( cont 2)

  • SYNTAX: sintaxis de la instancia del objeto.
  • ACCESS: formas en que una instancia de un objeto puede ser accedida ( read-only, read-write, write-only, not-accesible).
  • STATUS: requisitos de implementación:
    • Mandatory: obigatorio.
    • Optional: opcional.
    • Deprecated: debe ser soportado, pero será quitado en la siguiente versión de MIBs.
    • Obsolete: ya no es necesario implementarlo.
  • DescrPart: ( opcional) descripción textual de la semántica del objeto.
  • ReferPart: ( opcional) referencia cruzada textual a un objeto definido en otra MIB.
  • IndexPart: define índices de las tablas.
  • DefValPart: ( opcional) valor por defecto usado cuando se crea una instancia del objeto.
  • VALUE NOTATION: OID asignado al objeto.

SMIv2:OBJECT TYPE MACRO

OBJECT-TYPE MACRO ::=
BEGIN

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

Declarados en la siguiente transparencia

ReferPart
IndexPart
DefValPart
VALUE NOTATION ::= value ( VALUE ObjectName)
END

http://tools.ietf.org/html/rfc2578

SMIv2:OBJECT TYPE MACRO ( cont)

Syntax ::= type | "BITS" "{" NamedBits "}"
NamedBits ::= NamedBit | NamedBits "," NamedBit
NamedBit ::= identifier "(" number ")"
UnitsPart ::= "UNITS" Text | empty
Access ::= "not-accessible" | "accessible-for-notify" | "read-only" | "read-write" | "read-create"
Status ::= "current" | "deprecated" | "obsolete"
ReferPart ::= "REFERENCE" Text | empty
IndexPart ::= "INDEX" "{" IndexTypes "}" | "AUGMENTS" "{" Entry "}" | empty
IndexTypes ::= IndexType | IndexTypes "," IndexType
IndexType ::= "IMPLIED" Index | Index
Index ::= value ( ObjectName)
Entry ::= value ( ObjectName)
DefValPart ::= "DEFVAL" "{" Defvalue "}" | empty
Defvalue ::= value ( ObjectSyntax) | "{" BitsValue "}"
BitsValue ::= BitNames | empty
BitNames ::= BitName | BitNames "," BitName
BitName ::= identifier
Text ::= value ( IA5String)

Nota: en esta diapositiva el extractor convirtió los operadores de alternancia ”|” de la notación BNF en separadores de tabla rotos; se han restaurado a partir del contenido de las celdas, sin añadir ni quitar palabras.

Otras Macros definidas en SMIv2

  • MODULE-IDENTITY: comunica información y semántica de un módulo
  • OBJECT-IDENTITY: información sobre OIDs administrativos
  • NOTIFICATION-TYPE: define información de notificación
  • TEXTUAL-CONVENTION: comunica la sintaxis y semántica asociada a una convención textual
  • OBJECT-GROUP: grupos de objetos relacionados
  • NOTIFICATION-GROUP: define grupos de notificaciones
  • MODULE-COMPLIANCE: informa sobre los requisitos mínimos para implementar un módulo MIB.
  • AGENT-CAPABILITIES: informa sobre las capacidades de una entidad agente SNMPv2

SMIv2: MODULE-IDENTITY MACRO

MODULE-IDENTITY MACRO ::=
BEGIN

TYPE NOTATION ::=
"LAST-UPDATED" value ( Update ExtUTCTime)
"ORGANIZATION" Text
“CONTACT-INFO" Text
"DESCRIPTION" Text RevisionPart
VALUE NOTATION ::= value ( VALUE OBJECT IDENTIFIER)
RevisionPart ::= Revisions | empty
Revisions ::= Revision | Revisions, Revision
Revision ::=
"REVISION" value ( Update ExtUTCTime)
"DESCRIPTION" Text
Text ::= value ( IA5String)
END

Ejemplo ( Uah-tel-p2ptls MODULE-IDENTITY)

Uah-tel-p2ptls MODULE-IDENTITY
LAST-UPDATED "9505241813Z"
ORGANIZATION ”Alcala University”
CONTACT-INFO ”xxx@uah.es"
DESCRIPTION "The MIB module for entities implementing the
p2ptls protocol developed in UAH."
REVISION "9505241813Z"
DESCRIPTION "The latest version of this MIB module."
REVISION "9210070433Z"
DESCRIPTION "The initial version of this MIB module.”
::= { experimental xx }

SMIv2: OBJECT-IDENTITY MACRO

OBJECT-IDENTITY MACRO ::=
BEGIN

TYPE NOTATION ::=
"STATUS" Status
"DESCRIPTION" Text ReferPart
VALUE NOTATION ::= value ( VALUE OBJECT IDENTIFIER)
Status ::= "current" | "deprecated" | "obsolete"
ReferPart ::= "REFERENCE" Text | empty
Text ::= value ( IA5String)
END

Ejemplo ( uah-tel OBJECT-IDENTITY)

uah-tel OBJECT-IDENTITY
STATUS current
DESCRIPTION "The authoritative identity of the
Telematic group in UAH."
::= { uah 1 }

SMIv2: NOTIFICATION-TYPE MACRO

NOTIFICATION-TYPE MACRO ::=
BEGIN

TYPE NOTATION ::=
ObjectsPart
"STATUS" Status
"DESCRIPTION" Text ReferPart
VALUE NOTATION ::= value ( VALUE NotificationName)
ObjectsPart ::= "OBJECTS" "{" Objects "}" | empty
Objects ::= Object | Objects ","Object
Object ::= value ( ObjectName)
Status ::= "current" | "deprecated" | "obsolete"
ReferPart ::= "REFERENCE" Text | empty
Text ::= value ( IA5String)
END

Ejemplo ( linkUp NOTIFICATION-TYPE)

linkUp NOTIFICATION-TYPE
OBJECTS { ifIndex }
STATUS current
DESCRIPTION "A linkUp trap signifies that the SNMPv2
entity, acting in an agent role, recognizes that one of the
communication links represented in its configuration has
come up."
::= { snmpTraps 4 }

TEXTUAL-CONVENTION for SMIv2 ( RFC2579)

TEXTUAL-CONVENTION MACRO ::=BEGIN
TYPE NOTATION ::= DisplayPart
"STATUS" Status
"DESCRIPTION" Text
ReferPart
"SYNTAX" Syntax
VALUE NOTATION ::= value ( VALUE Syntax) -- adapted ASN.1
DisplayPart ::= "DISPLAY-HINT" Text | empty
Status ::= "current” | "deprecated” | "obsolete”
ReferPart ::= "REFERENCE" Text | empty
Syntax ::= type | "BITS" "{" NamedBits "}"
NamedBits ::= NamedBit | NamedBits "," NamedBit
NamedBit ::= identifier "(" number ")" -- number is nonnegative
END

http://tools.ietf.org/html/rfc2579

TEXTUAL-CONVENTION for SMIv2 ( RFC2579) ( cont)

Declaraciones con la macro:

  • DisplayString
  • PhysAddress
  • MacAddress
  • TruthValue
  • TestAndIncr
  • AutonomuosType
  • InstancePointer
  • VariablePointer
  • RowPointer
  • RowStatus
PhysAddress ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1x:"
STATUS current
DESCRIPTION "Represents media- or physical-level addresses."
SYNTAX OCTECT STRING

1 x: indica el formato de representación del octect string. Cada octeto se visualiza en hexadecimal separado por “:”.

OBJECT GROUP MACRO ( RFC2580)

Estructura:

  • ObjectParts: secuencia de elementos de tipo ObjectName
  • STATUS: current, deprecated, obsolete
  • DESCRIPTION: Text
  • ReferPart: REFERENCE Text | empty

Ver declaraciones en http://tools.ietf.org/html/rfc2580

snmpGroup OBJECT-GROUP
OBJECTS {
snmpInPkts,
snmpInBadVersions,
snmpInASNParseErrs,
snmpBadOperations,
snmpSilentDrops,
snmpProxyDrops,
snmpEnableAuthenTraps }
STATUS current
DESCRIPTION "A collection of objects
providing basic instrumentation and
control of an SNMPv2 entity."
::= { snmpMIBGroups 8 }

NOTIFICATION-GROUP MACRO ( RFC2580)

Estructura:

  • NotificationtParts: secuencia de elementos de tipo NotificationName
  • STATUS: current, deprecated, obsolete
  • DESCRIPTION: Text
  • ReferPart: REFERENCE Text | empty

Ver declaraciones en http://tools.ietf.org/html/rfc2580

snmpBasicNotificationsGroup NOTIFICATION-GROUP
NOTIFICATIONS { coldStart, authenticationFailure }
STATUS current
DESCRIPTION "The two notifications which an SNMPv2 entity is required to
implement."
::= { snmpMIBGroups 7 }

MODULE-COMPLIANCE ( RFC2580)

Estructura:

  • STATUS: current, deprecated, obsolete
  • DESCRIPTION: Text
  • ReferPart: REFERENCE Text | empty
  • ModulePart: secuence of
    • ◼ ModuleName: ModuleIdentifier ( OID) | empty,
    • ◼ MandatoryPart: secuence of groups ( OID) | empty
    • ◼ CompliancePart: secuence of ComplianceGroup {OID, DESCRIPTION Text) | Object ( ObjectName, SyntaxtPart, WriteSyntaxtPart, AccessPart)
telMIB Compliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION "The compliance statement for TELv2 entities which implement the TELv2 MIB."
MODULE -- compliance to the containing MIB module
MANDATORY-GROUPS { telSystemGroup, telStatsGroup, telTrapGroup, telSetGroup, telNotificationsGroup }
GROUP telV1Group
DESCRIPTION "The telV1 group is mandatory only for those TELv2 entities which also implement TELv1.”
::= { telMIBCompliances 1 }

AGENT-CAPABILITIES ( RFC2580)

Estructura:

  • PRODUCT-RELEASE Text
  • STATUS: current, deprecated, obsolete
  • DESCRIPTION: Text
  • ReferPart: REFERENCE Text | empty
  • ModulePart empty | Secuence of Modules ( Name, Groups, Variations))
exampleAgent AGENT-CAPABILITIES
PRODUCT-RELEASE "ACME Agent release 1.1 for 4BSD"
STATUS current
DESCRIPTION "ACME agent for 4BSD"
SUPPORTS SNMPv2-MIB
INCLUDES { systemGroup, snmpGroup, snmpSetGroup, snmpBasicNotificationsGroup }
VARIATION coldStart
DESCRIPTION "A coldStart trap is generated on all reboots."

AGENT-CAPABILITIES ( RFC2580) ( cont)

SUPPORTS IF-MIB
INCLUDES { ifGeneralGroup, ifPacketGroup }
VARIATION ifAdminStatus
SYNTAX INTEGER { up ( 1), down ( 2) }
DESCRIPTION "Unable to set test mode on 4BSD"
VARIATION ifOperStatus
SYNTAX INTEGER { up ( 1), down ( 2) }
DESCRIPTION "Information limited on 4BSD"

SUPPORTS IP-MIB
*******************

SUPPORTS TCP-MIB
*******************

SUPPORTS UDP-MIB
*******************
::= { acmeAgents 1 }

Ejemplos de declaraciones

RFC1213-MIB DEFINITIONS ::= BEGIN
IMPORTS mgmt, NetworkAddress, IpAddress, Counter, Gauge,
TimeTicks FROM RFC1155-SMI
OBJECT-TYPE FROM RFC-1212;
PhysAddress ::= OCTET STRING
DisplayString ::= OCTET STRING –-size ( 0..255)
mib-2 OBJECT IDENTIFIER ::= { mgmt 1 } -- MIB-II
system OBJECT IDENTIFIER ::= { mib-2 1 }
interfaces OBJECT IDENTIFIER ::= { mib-2 2 }
at OBJECT IDENTIFIER ::= { mib-2 3 }
ip OBJECT IDENTIFIER ::= { mib-2 4 }
icmp OBJECT IDENTIFIER ::= { mib-2 5 }
tcp OBJECT IDENTIFIER ::= { mib-2 6 }
udp OBJECT IDENTIFIER ::= { mib-2 7 }
egp OBJECT IDENTIFIER ::= { mib-2 8 }
-- cmot OBJECT IDENTIFIER ::= { mib-2 9 }
transmission OBJECT IDENTIFIER ::= { mib-2 10 }
snmp OBJECT IDENTIFIER ::= { mib-2 11 }

sysDescr

sysDescr OBJECT-TYPE
SYNTAX DisplayString ( SIZE ( 0..255))
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A textual description of the entity. This value
should include the full name and version
identification of the system's hardware type,
software operating-system, and networking
software. It is mandatory that this only contain
printable ASCII characters."
::= { system 1 }

ifNumber

ifNumber OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of network interfaces ( regardless of
their current state) present on this system."
::= { interfaces 1 }

ipForwarding

ipForwarding OBJECT-TYPE
SYNTAX INTEGER {
forwarding ( 1), -- acting as a gateway
not-forwarding ( 2) -- NOT acting as a gateway
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The indication of whether this entity is acting
as an IP gateway in respect to the forwarding of
datagrams received by, but not addressed to, this
entity. IP gateways forward datagrams. IP hosts
do not ( except those source-routed via the host).
Note that for some managed nodes, this object may
take on only a subset of the values possible.
Accordingly, it is appropriate for an agent to
return a `badValue' response if a management
station attempts to change this object to an
inappropriate value."
::= { ip 1 }

Declaración de tablas

  • Nombre de la tabla: Table
  • Entry: tableEntry
  • Los elementos columnares.
  • El índice.

Cada tabla consiste en SEQUENCE OF TableEntry. Cada fila ( TableEntry) consiste en una SEQUENCE de elementos columnares.

Ejemplo de tabla: ipRoutingTable

ipRouteTable OBJECT-TYPE
SYNTAX SEQUENCE OF IpRouteEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"This entity's IP Routing table."
::= { ip 21 }

ipRouteEntry OBJECT-TYPE
SYNTAX IpRouteEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A route to a particular destination."
INDEX { ipRouteDest }
::= { ipRouteTable 1 }

IpRouteEntry ::= SEQUENCE {
ipRouteDest IpAddress,
ipRouteIfIndex INTEGER,
ipRouteMetric1 INTEGER,
ipRouteMetric2 INTEGER,
ipRouteMetric3 INTEGER,
ipRouteMetric4 INTEGER,
ipRouteNextHop IpAddress,
ipRouteType INTEGER,
ipRouteProto INTEGER,
ipRouteAge INTEGER,
ipRouteMask IpAddress,
ipRouteMetric5 INTEGER,
ipRouteInfo OBJECT IDENTIFIER
}

ipRouteDest OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 1 }

ipRouteIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 2 }

ipRouteMetric1 OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 3 }

ipRouteMetric2 OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 4 }

ipRouteMetric3 OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 5 }

ipRouteMetric4 OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 6 }

ipRouteNextHop OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 7 }

ipRouteType OBJECT-TYPE
SYNTAX INTEGER {
other ( 1), -- none of the following
invalid ( 2), -- an invalidated route route to directly
direct ( 3), -- connected ( sub-)network route to a non-local
remote ( 4) -- host/network/sub-network
}
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 8 }

ipRouteProto OBJECT-TYPE
SYNTAX INTEGER {
other ( 1), -- none of the following non-protocol information
-- e.g., manually
local ( 2), -- configured entries set via a network
netmgmt ( 3), -- management protocol obtained via ICMP,
icmp ( 4), -- e.g., Redirect the following are gateway routing
-- protocols
egp ( 5),
ggp ( 6),
hello ( 7),
rip ( 8),
is-is ( 9),
es-is ( 10),
ciscoIgrp ( 11),
bbnSpfIgp ( 12),
ospf ( 13)
bgp ( 14)}
ACCESS read-only
STATUS mandatory
::= { ipRouteEntry 9 }

ipRouteAge OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 10 }

ipRouteMask OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 11 }

ipRouteMetric5 OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
::= { ipRouteEntry 12 }

ipRouteInfo OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
ACCESS read-only
STATUS mandatory
::= { ipRouteEntry 13 }

Nota: esta tabla llegó con las declaraciones de ipRouteDest…ipRouteInfo repartidas en dos columnas por diapositiva y entrelazadas línea a línea por el extractor; se han reordenado por declaración usando los índices ::= { ipRouteEntry N } (1 a 13, todos presentes) como referencia, sin añadir ni quitar palabras.

Ejemplo de tabla: tcpConnTable

tcpConnTable OBJECT-TYPE
SYNTAX SEQUENCE OF TcpConnEntry
ACCESS not-accessible
STATUS mandatory
::= { tcp 13 }

tcpConnEntry OBJECT-TYPE
SYNTAX TcpConnEntry
ACCESS not-accessible
STATUS mandatory
INDEX { tcpConnLocalAddress, tcpConnLocalPort, tcpConnRemAddress, tcpConnRemPort }
::= { tcpConnTable 1 }

TcpConnEntry ::= SEQUENCE {
tcpConnState INTEGER,
tcpConnLocalAddress IpAddress,
tcpConnLocalPort INTEGER ( 0..65535),
tcpConnRemAddress IpAddress,
tcpConnRemPort INTEGER ( 0..65535)}

tcpConnState OBJECT-TYPE
SYNTAX INTEGER {
closed ( 1),
listen ( 2),
synSent ( 3),
synReceived ( 4),
established ( 5),
finWait1 ( 6),
finWait2 ( 7),
closeWait ( 8),
lastAck ( 9),
closing ( 10),
timeWait ( 11),
deleteTCB ( 12)
}
ACCESS read-write
STATUS mandatory
::= { tcpConnEntry 1 }

tcpConnLocalAddress OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
::= { tcpConnEntry 2 }

tcpConnLocalPort OBJECT-TYPE
SYNTAX INTEGER ( 0..65535)
ACCESS read-only
STATUS mandatory
::= { tcpConnEntry 3 }

tcpConnRemAddress OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The remote IP address for this TCP connection."
::= { tcpConnEntry 4 }

tcpConnRemPort OBJECT-TYPE
SYNTAX INTEGER ( 0..65535)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The remote port number for this TCP connection."
::= { tcpConnEntry 5 }

Nota: igual que en la tabla anterior, las declaraciones de tcpConnTable/tcpConnEntry/TcpConnEntry y de sus campos llegaron entrelazadas por columnas; se han reordenado por declaración usando los índices ::= { tcpConnEntry N } (1 a 5) como referencia.

  • Los módulos MIB se van actualizando con el tiempo:
    • RFC1213 : ip ( junto a otros protocolos) – Año 1991
    • RFC4293 : ip ( diferencia IPv4 e IPv6) – Año 2006

¿SNMP? ☺

Mensaje SNMP definido en ASN.1 : RFC1157

RFC1157-SNMP DEFINITIONS ::= BEGIN

IMPORTS
ObjectName, ObjectSyntax, NetworkAddress, IpAddress, TimeTicks
FROM RFC1155-SMI;

Message ::= SEQUENCE {
version INTEGER {version-1 ( 0)}, -- Version-1 for this RFC
community OCTET STRING, -- Community name
data ANY -- E.g., PDUs if trivial authentication is being used
}

PDUs ::= CHOICE {
get-request GetRequest-PDU,
get-next-request GetNextRequest-PDU,
get-response GetResponse-PDU,
set-request SetRequest-PDU,
trap Trap-PDU
}

GetRequest-PDU ::= [0] IMPLICIT PDU
GetNextRequest-PDU ::= [1] IMPLICIT PDU
GetResponse-PDU ::= [2] IMPLICIT PDU
SetRequest-PDU ::= [3] IMPLICIT PDU

PDU ::= SEQUENCE {
request-id INTEGER,
error-status INTEGER {noError ( 0), tooBig ( 1), noSuchName ( 2),
badValue ( 3), readOnly ( 4), genErr ( 5)},
error-index INTEGER, -- Sometimes ignored
variable-bindings VarBindList -- Values are sometimes ignored
}

Trap-PDU ::= [4] IMPLICIT SEQUENCE {
enterprise OBJECT IDENTIFIER, -- Type of object generating trap, see sysObjectID in [5]
agent-addr NetworkAddress, -- Address of object generating trap
generic-trap INTEGER { -- Generic trap type
coldStart ( 0), warmStart ( 1), linkDown ( 2), linkUp ( 3),
authenticationFailure ( 4), egpNeighborLoss ( 5),enterpriseSpecific ( 6)
},
specific-trap INTEGER, -- Specific code, present even if generic-trap is not enterpriseSpecific
time-stamp TimeTicks, -- Time elapsed between the last ( re)initialization of the network entity and the generation of the trap
variable-bindings VarBindList -- "interesting" information
}

VarBind ::= SEQUENCE {
name ObjectName,
value ObjectSyntax
}
VarBindList ::= SEQUENCE OF VarBind
END

Mensaje SNMPv2 definido en ASN.1 : RFC3416

SNMPv2-PDU DEFINITIONS ::= BEGIN
-- protocol data units
PDUs ::= CHOICE {
get-request GetRequest-PDU,
get-next-request GetNextRequest-PDU,
get-bulk-request GetBulkRequest-PDU,
response Response-PDU,
set-request SetRequest-PDU,
inform-request InformRequest-PDU,
snmpV2-trap SNMPv2-Trap-PDU,
report Report-PDU }
-- PDUs
GetRequest-PDU ::= [0] IMPLICIT PDU
GetNextRequest-PDU ::= [1] IMPLICIT PDU
Response-PDU ::= [2] IMPLICIT PDU
SetRequest-PDU ::= [3] IMPLICIT PDU
-- [4] is obsolete
GetBulkRequest-PDU ::= [5] IMPLICIT BulkPDU
InformRequest-PDU ::= [6] IMPLICIT PDU
SNMPv2-Trap-PDU ::= [7] IMPLICIT PDU
-- Usage and precise semantics of Report-PDU are not defined
-- in this document. Any SNMP administrative framework making
-- use of this PDU must define its usage and semantics.
Report-PDU ::= [8] IMPLICIT PDU
max-bindings INTEGER ::= 2147483647

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