Chapter 7 Overview

Chapter 7 Management Information Base (MIB) 1

Chapter 7 Overview Structure of management info

(SMI) Definition of mib-2 objects Use of MIB browser MIB compiler MIB editor


Intro In Chapter 6, we looked at SMI tree

o Here, interested in mib-2 branch On mib-2 branch

o There is an almost endless number of things that could be monitored

o But don’t want performance to suffero Therefore, mib-2 is limited


SMI We’re interested in

nodes under iso (1) Internet is under DoD

(DoD funded ARPA) Internet node now

administered by IAB All mib-2 objects underiso.org.dod.internet.mgmt.mi

b-2,or, equivalently, 1.3.6.1.2.1

mib-2 (1)

system (1)

sysDescr (1)

directory (1) mgmt (2) experimental (3) private (4)

internet (1)

(1) (2) (3) (4) (5) dod (6)

standard(0)

registration-authority

(1)

member-body(2)

joint-iso-ccitt (2)

root

ccitt (0) iso (1)

identified-organization

(3)

enterprises (1)

sysName (5)

ip (4)


iso (1) standard (0) has a node for each

approved “international standard” registration-authority (1) is reserved for

OSI registration authorities member-body (2) has node for each

country in ISO/IEC identified-organization (3) has node for

“any organization that can justify it”o Currently only NIST and DoD


dod (6) Under dod (6), there is only internet (1) Under internet (1)

o directory (1) for DoD serviceso management (2) for nodes defined in RFCs

(administered by IANA)o experimental (3) administered by IANAo private (4), enterprise (1) for proprietary

MIBs


management (2) mib-2 (1) contains MIB II objects mib-2 is the focus of this chapter MIB objects specified with subset of ASN.1

o Subset used is minimum requiredo Consistent with SNMP approach (keep it

simple) More details on ASN.1 in Appendix B

o Lots of other sources of info availableo ASN.1 is like a programming language


MIB Objects Object-Type Macro

o Written in ASN.1 Acts as a template for

constructing MIB objects Each line is a clause Almost all mib-2 objects

created from these clauseso Exceptions are…o …ReferPart and DefValPart

OBJECT-TYPE MACRO:: =BEGINTYPE NOTATION :: = "SYNTAX" type ( TYPE ObjectSyntax )

"ACCESS" Access "STATUS" Status

DescrPartReferPartIndexPartDefValPartDisplayString

VA LUE NOTATION :: = value (VA LUE ObjectName )

Access :: = "read-only"| "read-write"| "write-only"| "not-accessible

Status :: = "mandatory"| "optional"| "obsolete"

DescrPart : : = "DESCRIPTION" value (description DisplayString | empty )

ReferPart : : = "REFERENCE" value ( reference DisplayString | empty )

IndexPart : : = "INDEX" "{" IndexTypes "}"

IndexTypes : : = IndexType | IndexTypes "," IndexType

IndexType : : = value ( indexobject ObjectName ) | type ( IndexType )

DefValPart : : = "DEFVAL" "{" value (defvalue ObjectSyntax ) "}" | empty

DisplayString : : = OCTET STRING SIZE (0..255)END


sysDescr Object sysDescr

includeso SYNTAXo ACCESSo STATUSo DESCRIPTIONo value

OBJECT-TYPE MACRO:: =BEGINTYPE NOTATION :: = "SYNTAX" type ( TYPE ObjectSyntax )

"ACCESS" Access "STATUS" Status

DescrPartReferPartIndexPartDefValPartDisplayString

VA LUE NOTATION :: = value (VA LUE ObjectName )

Access :: = "read-only"| "read-write"| "write-only"| "not-accessible

Status :: = "mandatory"| "optional"| "obsolete"

DescrPart : : = "DESCRIPTION" value (description DisplayString | empty )

ReferPart : : = "REFERENCE" value ( reference DisplayString | empty )

IndexPart : : = "INDEX" "{" IndexTypes "}"

IndexTypes : : = IndexType | IndexTypes "," IndexType

IndexType : : = value ( indexobject ObjectName ) | type ( IndexType )

DefValPart : : = "DEFVAL" "{" value (defvalue ObjectSyntax ) "}" | empty

DisplayString : : = OCTET STRING SIZE (0..255)END


sysDescr Object Anything following

“” is a comment system 1 is node 1

under “system” in SMI tree

system is ato 1.3.6.1.2.1.1

So, system 1 is ato 1.3.6.1.2.1.1.1

sysDescr OBJECT-TYPE --the object has the ObjectName sysDescr and is of type--OBJECT-TYPE, i.e. its type is defined by the OBJECT---TYPE MACRO. All mib-2 objects are of--OBJECT-TYPE. As opposed to the C language, the type--of objects is put after the object name.

SYNTAX DisplayString(SIZE (0..255) --the MACRO says that this type is ObjectSyntax.

--ObjectSyntax type is defined in RFC 1155 as a CHOICE--between a number of types. One of these types is--DisplayString (see Appendix B)

ACCESS read-only --read-only is one of the options provided by the Access--production. Productions are supporting assignments--which complete ("resolve" is the formal word) type and--value definitions in the assignment list by using more--detailed assignments.

STATUS mandatory --this is one of the options provided by the Status--production

DESCRIPTION "A textural 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. Description should only contain printable ASCII characters."

value {system 1} --the MACRO definition says that VA LUE is ObjectName--type. ObjectName is defined in RFC 1155 to be OBJECT--IDENTIFIER type which has the value {system 1}for--this object as seen in Figure 7-1


sysName What info does

sysName provide?o Node’s domain name

Where does sysName live in SMI tree?

Recall, system is ato 1.3.6.1.2.1.1

So system 5 is ato 1.3.6.1.2.1.1.5

sysName OBJECT-TYPE -- the object has the name sysName and is of type-- OBJECT-TYPE, i.e. the MACRO name.

SYNTAX DisplayString(SIZE (0..255) --the MACRO says that this type is ObjectSyntax. This

--ObjectSyntax type is defined in RFC 1155 as a CHOICE--between a number of types. One of these is DisplayString--See Appendix B

ACCESS read-write -- this is one of the options provided by the Access-- production.

STATUS mandatory -- this is one of the options provided by the Status-- production

DESCRIPTION "An administratively-assigned name for this managednode. By convention, this is the node's fully qualifieddomain name."

value {system 5} -- the MACRO says that value is ObjectName type--ObjectName is defined in RFC 1155 to be OBJECT--IDENTIFIER which is {system 5} for this object as seen-- in Figure 7-1


ipAddrTable Let’s consider a more complex

object definition Consider ipAddrTable

o 4 columnso 1 row for each interface

ipAddrTable {mib-2.4.20}ipAdEntAddr

{mib-2.4.20.1.1}

ipAdEntIndex

{mib-2.4.20.1.2}

ipAdEntNetMask

{mib-2.4.20.1.3}

IpAdEntBcastAddr

{mib-2.4.20.1.4}

IpAdEntReasmMaxSize{mib-2.4.20.1.5}

1234


ipAddrTable

Each entry (row) in table has object identifier ipAddrEntry, mib-2.4.20.1o E.g., object identifier of object in column

ipAdEntNetMask is mib-2.4.20.1.3 Index object is ipAdEntAddr (from 1 to

N)o ipAdEntBcastAddr for interface 2 is at

mib-2.4.20.1.4.2o ipAdEntNetMask for interface 4 is at

mib-2.4.20.1.3.4

ipAddrTable {mib-2.4.20}ipAdEntAddr

{mib-2.4.20.1.1}

ipAdEntIndex

{mib-2.4.20.1.2}

ipAdEntNetMask

{mib-2.4.20.1.3}

IpAdEntBcastAddr

{mib-2.4.20.1.4}

IpAdEntReasmMaxSize{mib-2.4.20.1.5}

1234


ipAddrTable

Uses template on previous slide

ipAddrTable OBJECT-TYPE

SYNTAX SEQUENCE OF ipAddrEntry --a SEQUENCE OF is a constructed ASN.1--type which is a list of objects of the same--type. In the case of a table, it means a list--of the rows in the table. ipAddrEntry is--another object defined in Figure 7-6.

ACCESS not-accessible --rows are not accessible. Only objects in a--row are accessible

STATUS mandatory --must be included in the object

DESCRIPTION --"The table of addressing information-- relevant to this entry's IP addresses"

value {ip 20 } -- ip is the object under mib-2 that contains--the object ipAddrTable which has the--OBJECT IDENTIFIER {ip 20}


ipAddrEntry Use ipAddrTable Note

o Sequence element is a row

o Value is ipAddrTable 1, i.e., mib-2.4.20.1

ipAddrEntry OBJECT-TYPE --this MACRO defines the object--ipAddrEntry. It is the name of any--row in the table

SYNTAX ipAddrEntry --ipAddrEntry is of type SEQUENCE as--defined below in the next panel

ACCESS not accessible -- previously defined

STATUS mandatory -- previously defined

DESCRIPTION --Information relative to one of the--IP Addresses in the table. This information--includes the IP Address itself.

INDEX {ipAdEntAddr} --referring to the template in Figure 7-2,--IndexTypes resolves to ipAdEntAddr. In other--words, there is only one index type in this case.--As we see in the next panel, this Index Type is of--type ipaddress that is defined elsewhere to be--OCTET STRING of SIZE 4. Here we see an--example of nesting type-definitions which occur--frequently in MIB object definitions. Thus in this--case, only ipAdEntAddr is used to determine the--desired row.

value {ipAddrTable 1} --ipAddrTable 1 is the Object Identifier of all rows--in the table

ipAddrEntry : : = SEQUENCE { --a SEQUENCE is a list of objects that may be of--different types In this example, the SEQUENCE--corresponds to the following objects in one row--of the table

ipAdEntAddr ipAddress --ObjectName and typeipAdEntIfIndex INTEGER --ObjectName and typeipAdEntNetMask ipAddress --ObjectName and typeipAdEntBcastAddr INTEGER --ObjectName and typeipAdEntReasmMaxSize --ObjectName and type

INTEGER ( 0 .. 65535 )}


NMS Presentation of iso Meterware view

of iso branch SNMP can only

access leaf node Note that IP

address of WS1 is 192.192.192.223


NMS Presentation of mib-2 Meterware view

of mib-2 Note 10 original

groups o system thru snmp

13 extensionso rmon, etc.


NMS View of ipAddrTable Meterware view

of ipAdderTable


NMS View of ipAddrTable Meterware view

of value in ipAdderTable

Note that ipAdEntAddr is index object


WS1 ipAddrTable

ipAdEntAddro 127.0.0.1 is loopback address on WS1o 192.192.192.233 is IP address of NIC

ipAdEntIfIndexo 1 identifies interface 127.0.0.1 in ifTableo 2 identifies 192.192.192.233 in ifTable

WS1 ipAddrTable {1.3.6.1.2.1.4.20}ipAdEntAddr

{1.3.6.1.2.1.4.20.1.1}ipAdEntIfIndex

{1.3.6.1.2.1.4.20.1.2}ipAdEntNetMask

{1.3.6.1.2.1.4.20.1.3}ipAdEntBcastAddr{1.3.6.1.2.1.4.20.1.4}

ipAdEntReasmMax Size{1.3.6.1.2.1.4.20.1.5}

127.0.0.1 1 255.0.0.0 1 65535192.192.192.233 2 255.255.255.248 1 65535

Note: Each row in the table has the OBJECT IDENTIFIER {1.3.6.1.2.1.4.20.1}for ipAddrEntry


WS1 ipAddrTable

ipAdNetMask mask for addresses ipAdEntBcastAdd

o Indicates broadcast address ipAdEntReasmmax Size

o Max size of reassembled datagram

WS1 ipAddrTable {1.3.6.1.2.1.4.20}ipAdEntAddr

{1.3.6.1.2.1.4.20.1.1}ipAdEntIfIndex

{1.3.6.1.2.1.4.20.1.2}ipAdEntNetMask

{1.3.6.1.2.1.4.20.1.3}ipAdEntBcastAddr{1.3.6.1.2.1.4.20.1.4}

ipAdEntReasmMax Size{1.3.6.1.2.1.4.20.1.5}

127.0.0.1 1 255.0.0.0 1 65535192.192.192.233 2 255.255.255.248 1 65535

Note: Each row in the table has the OBJECT IDENTIFIER {1.3.6.1.2.1.4.20.1}for ipAddrEntry


Index Object NMS might not know index object Then how can NMS construct table? To get ipAdEntNetMask column…

o GetNextRequest(ipAdEntNetMask) to get ipAdEntNetMask.1

o GetNextRequest(ipAsEntNetMask.1) to get ipAdEntNetMask.2

o GetNextRequest(ipAsEntNetMask.2) to get ipAdEntBcastAddr.1, and so on…


Meterware Network View Summary view


Meterware Network View MIB browser for Switch 2


Set Command Check ifAdminStatus

of Switch2o All 27 ports are

“administratively up”o Only ports 3 and 25

are connectedo Port 3 connected to

SERVERo Port 25 connected to

10Base2 cable


Set Command Note that

Port 3 of Switch2 connects to SERVER ROUTER

PSTN

WAN

HUB

PROBE 2 WS 2 SERVER PROBE 1

SWITCH 1SWITCH 2

SUBNET 2 SUBNET 1

LAN

NMS

WS 1

10BASE2 Segment

Router

= port 3


Set Command Ping SERVER (192.192.192.242) from WS1


Set Command Set ifAdminStatus of port 3 on

switch2 to “down”


Set Command Meterwar

e shows port 3 is downo 1 == upo 2 ==

down


Set Command Again, ping SERVER from WS1


Enterprise MIBs hp is node for Hewlett Packard What, no Cisco node?


Cisco Catalyst MIB

-- product family

fastLink OBJECT IDENTIFIER ::= { products 1 }

-- groups

seriesG2xx OBJECT IDENTIFIER ::= { fastLink 2 }series2000 OBJECT IDENTIFIER ::= { fastLink 3 }

-- LAST-UPDATED "9708040000Z" -- ORGANIZATION "Cisco Systems, Inc." -- CONTACT-INFO -- " Cisco Systems -- Customer Service -- -- Postal: 170 W Tasman Drive -- San Jose, CA 95134 -- USA -- -- Tel: +1 800 553-NETS -- -- E-mail: [email protected]"

-- DESCRIPTION-- "MIB for the Catalyst 1900 and 2820,-- Catalyst 2100 and 2800,-- EtherSwitch 12XX and 14XX"

sysInfo OBJECT IDENTIFIER ::= { series2000 1 }

sysConfig OBJECT IDENTIFIER ::= { series2000 2 }

port OBJECT IDENTIFIER ::= { series2000 3 }

netMgmt OBJECT IDENTIFIER ::= { series2000 4 }

upgrade OBJECT IDENTIFIER ::= { series2000 5 }

vlan OBJECT IDENTIFIER ::= { series2000 6 }

bandwidthUsage OBJECT IDENTIFIER ::= { series2000 7 }

bridgeGroup OBJECT IDENTIFIER ::= { series2000 8 }

-- the following group manages G2xx modules

esModuleBasic OBJECT IDENTIFIER ::= { seriesG2xx 1 }

--++++++++++++++++++++++++++++++++++++++++++++++++++++++++

-- General System Information

--++++++++++++++++++++++++++++++++++++++++++++++++++++++++

sysInfoFwdEngineRevision OBJECT-TYPESYNTAX INTEGERACCESS read-onlySTATUS mandatoryDESCRIPTION

"Returns the revision number of the forwardingengine ASIC."

::= { sysInfo 1 }

sysInfoBoardRevision OBJECT-TYPESYNTAX INTEGERACCESS read-onlySTATUS mandatoryDESCRIPTION

"Returns the revision number of the switch mainboard on which the system firmware resides."

::= { sysInfo 2 }

sysInfoTotalNumberOfPorts OBJECT-TYPESYNTAX INTEGERACCESS read-onlySTATUS mandatoryDESCRIPTION

"The total number of physical network ports.fixed configuration - 27, 15 or 14 ports,modular configuration - 25 - 41 portsThis object does NOT represent the upper bound ofindices into port tables.See sysInfoNumberOfSwitchPorts andsysInfoNumberOfSharedPorts for that purpose."

::= { sysInfo 3 }

--STAND-ALONE-ETHERNET-SWITCH-MIB --REVISION 1.00

DEFINITIONS ::= BEGIN

IMPORTS enterprises, Counter, Gauge, IpAddress, TimeTicks FROM RFC1155-SMI TRAP-TYPE FROM RFC-1215 OBJECT-TYPE FROM RFC-1212 Timeout FROM BRIDGE-MIB sysName, ifIndex, DisplayString FROM RFC1213-MIB;

grandjunction OBJECT IDENTIFIER ::= { enterprises 437 }

--categories

products OBJECT IDENTIFIER ::= { grandjunction 1 }


Compile Cisco MIB Compile

ESSWITCH-MIB-MY2

1

2

3


Compile Cisco MIB Compile

ESSWITCH-MIB-MY2


Enterprise Node Why “grandjunction” ?


Grandjunction node Children of “series 2000”


sysInfo node Select sysInfoNumberOfSwitchPorts… What should we find?


sysInfo node What does this

tell us? Switch has 27

ports Why not just

count ports? Allows for

remote mgmt!


MIB Editor We have seen how to construct

MIB objects as text files and compile

There are MIB editorso User-friendly editor to make correct

source codeo May be part of NMS or standalone


Chapter 7 Summary Formal definition of MIB objects Syntax of ASN.1 Simple and constructed mib-2

objects Meterware screen shots Compiled a MIB module MIB editor

Documents

Chapter 7 Overview