chapter01走进计算机技术世界课件

Chapter9

NetworkManagementComputerNetworking:ATopDownApproachFeaturingtheInternet,

3rdedition.

JimKurose,KeithRoss

Addison-Wesley,July2004.

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NetworkManagementChapter9:NetworkManagementChaptergoals:

introductiontonetworkmanagementmotivationmajorcomponentsInternetnetworkmanagementframeworkMIB:managementinformationbaseSMI:datadefinitionlanguageSNMP:protocolfornetworkmanagementsecurityandadministrationpresentationservices:ASN.12

NetworkManagementChapter9outlineWhatisnetworkmanagement?Internet-standardmanagementframeworkStructureofManagementInformation:SMIManagementInformationBase:MIBSNMPProtocolOperationsandTransportMappingsSecurityandAdministrationASN.13

NetworkManagementWhatisnetworkmanagement?autonomoussystems(aka“network”):100sor1000sofinteractinghardware/softwarecomponentsothercomplexsystemsrequiringmonitoring,control:jetairplanenuclearpowerplantothers?"Networkmanagementincludesthedeployment,integrationandcoordinationofthehardware,software,andhumanelementstomonitor,test,poll,configure,analyze,evaluate,andcontrolthenetworkandelementresourcestomeetthereal-time,operationalperformance,andQualityofServicerequirementsatareasonablecost."

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NetworkManagementInfrastructurefornetworkmanagementagentdataagentdataagentdataagentdatamanageddevicemanageddevicemanageddevicemanageddevicemanagingentitydatanetworkmanagementprotocoldefinitions:manageddevicescontainmanagedobjectswhosedataisgatheredintoaManagementInformationBase(MIB)

managingentity5

NetworkManagementNetworkManagementstandardsOSICMIPCommonManagementInformationProtocoldesigned1980’s:theunifyingnetmanagementstandardtooslowlystandardizedSNMP:SimpleNetworkManagementProtocolInternetroots(SGMP)startedsimpledeployed,adoptedrapidlygrowth:size,complexitycurrently:SNMPV3defactonetworkmanagementstandard6

NetworkManagementChapter9outlineWhatisnetworkmanagement?Internet-standardmanagementframeworkStructureofManagementInformation:SMIManagementInformationBase:MIBSNMPProtocolOperationsandTransportMappingsSecurityandAdministrationASN.17

NetworkManagementSNMPoverview:4keypartsManagementinformationbase(MIB):distributedinformationstoreofnetworkmanagementdataStructureofManagementInformation(SMI):datadefinitionlanguageforMIBobjectsSNMPprotocolconveymanager<->managedobjectinfo,commandssecurity,administrationcapabilitiesmajoradditioninSNMPv38

NetworkManagementSMI:datadefinitionlanguage

Purpose:syntax,semanticsofmanagementdatawell-defined,unambiguousbasedatatypes:straightforward,boringOBJECT-TYPEdatatype,status,semanticsofmanagedobjectMODULE-IDENTITYgroupsrelatedobjectsintoMIBmoduleBasicDataTypesINTEGERInteger32Unsigned32OCTETSTRINGOBJECTIDENTIFIEDIPaddressCounter32Counter64Guage32TimeTicksOpaque9

NetworkManagementSNMPMIBOBJECTTYPE:OBJECTTYPE:OBJECTTYPE:objectsspecifiedviaSMIOBJECT-TYPEconstructMIBmodulespecifiedviaSMIMODULE-IDENTITY(100standardizedMIBs,morevendor-specific)MODULE10

NetworkManagementSMI:Object,moduleexamplesOBJECT-TYPE:

ipInDeliversMODULE-IDENTITY:

ipMIBipInDeliversOBJECTTYPESYNTAXCounter32MAX-ACCESSread-onlySTATUScurrentDESCRIPTION“ThetotalnumberofinputdatagramssuccessfullydeliveredtoIPuser-protocols(includingICMP)”::={ip9}ipMIBMODULE-IDENTITYLAST-UPDATED“941101000Z”ORGANZATION“IETFSNPv2WorkingGroup”CONTACT-INFO“KeithMcCloghrie

……”DESCRIPTION“TheMIBmoduleformanagingIPandICMPimplementations,butexcludingtheirmanagementofIProutes.”REVISION“019331000Z”………::={mib-248}11

NetworkManagementMIBexample:UDPmoduleObjectIDNameTypeComments.UDPInDatagramsCounter32total#datagramsdeliveredatthisnode.UDPNoPortsCounter32#underliverabledatagrams noappatportl.UDInErrorsCounter32#undeliverabledatagrams allotherreasons.UDPOutDatagramsCounter32#datagramssent.udpTable SEQUENCEoneentryforeachport inusebyapp,givesport# andIPaddress12

NetworkManagementSNMPNamingquestion:howtonameeverypossiblestandardobject(protocol,data,more..)ineverypossiblenetworkstandard??answer:ISOObjectIdentifiertree:

hierarchicalnamingofallobjectseachbranchpointhasname,number.ISOISO-ident.Org.USDoDInternetudpInDatagramsUDPMIB2management13

NetworkManagementCheckoutwww.alvestrand.no/harald/objectid/top.htmlOSI

Object

Identifier

Tree14

NetworkManagementSNMPprotocolTwowaystoconveyMIBinfo,commands:agentdataManageddevicemanagingentityresponseagentdataManageddevicemanagingentitytrapmsgrequestrequest/responsemodetrapmode15

NetworkManagementSNMPprotocol:messagetypesGetRequestGetNextRequestGetBulkRequestMgr-to-agent:“getmedata”(instance,nextinlist,block)MessagetypeFunctionInformRequestMgr-to-Mgr:here’sMIBvalueSetRequestMgr-to-agent:setMIBvalueResponseAgent-to-mgr:value,responsetoRequestTrapAgent-to-mgr:informmanagerofexceptionalevent16

NetworkManagementSNMPprotocol:messageformats17

NetworkManagementSNMPsecurityandadministrationencryption:DES-encryptSNMPmessageauthentication:compute,sendMIC(m,k):computehash(MIC)overmessage(m),secretsharedkey(k)protectionagainstplayback:usenonceview-basedaccesscontrolSNMPentitymaintainsdatabaseofaccessrights,policiesforvarioususersdatabaseitselfaccessibleasmanagedobject!18

NetworkManagementChapter9outlineWhatisnetworkmanagement?Internet-standardmanagementframeworkStructureofManagementInformation:SMIManagementInformationBase:MIBSNMPProtocolOperationsandTransportMappingsSecurityandAdministrationThepresentationproblem:ASN.119

NetworkManagementThepresentationproblemQ:doesperfectmemory-to-memorycopysolve“thecommunicationproblem”?A:notalways!problem:differentdataformat,storageconventionsstruct{charcode;

intx;}test;test.x=256;test.code=‘a’a0000000100000011a0000001100000001test.codetest.xtest.codetest.xhost1formathost2format20

NetworkManagementAreal-lifepresentationproblem:aging60’shippie2004teenagergrandma21

NetworkManagementPresentationproblem:potentialsolutions1.

Senderlearnsreceiver’sformat.Sendertranslatesintoreceiver’sformat.Sendersends.real-worldanalogy?prosandcons?2.Sendersends.Receiverlearnssender’sformat.Receivertranslateintoreceiver-localformatreal-world-analogyprosandcons?3.Sendertranslateshost-independentformat.Sends.Receivertranslatestoreceiver-localformat.real-worldanalogy?prosandcons?22

NetworkManagementSolvingthepresentationproblem1.

Translatelocal-hostformattohost-independentformat2.Transmitdatainhost-independentformat3.Translatehost-independentformattoremote-hostformataging60’shippie2004teenagergrandma23

NetworkManagementASN.1:AbstractSyntaxNotation1ISOstandardX.680usedextensivelyinInternetlikeeatingvegetables,knowingthis“goodforyou”!defineddatatypes,objectconstructorslikeSMIBER:BasicEncodingRulesspecifyhowASN.1-defineddataobjectstobetransmi