网络管理和基础知识

网络管理的基础知识代理管理数据库管理系统管理实体网络代理管理数据库可管理的设备网管协议网络管理的体系结构代理管理数据库简单网络管理协议(SNMP)•SNMPV1-借助应用层协议传递信息•SNMPV2–性能得到提高•SNMPV3–多语种支持–更高的安全性网络管理系统(NMS)网络管理应用代理管理信息库(MIB)可管理设备SNMPSNMP报文的类型ManagerManagedDeviceAgentMIBGetRequestGetNextRequestSetRequestGetResponseTrapRetrievesvalueofspecificMIBvariableRetrievesnextissuanceofMIBvariableModifiesthevalueofaMIBvariableContainsvaluesofrequestedvariableTransmitsanunsolicitedalarmcondition网络管理系统(NMS)网络管理应用代理管理信息库(MIB)可管理设备SNMP管理信息数据库•管理对象的数据库•MIBI–114个标准对象–网络错误和配置管理的基本对象•MIBII–扩展的MIBI–185个管理对象•其他的标准MIBs–RMON,host,router,...•专有MIBs–标准MIBs的补充网络管理系统(NMS)•定期扫描网络•接受陷阱•收集并显示信息•一体化的平台•例如:HPOpenView网络管理系统(NMS)网络管理应用代理管理信息库(MIB)可管理设备ManagedDevice网络管理协议远程监控协议(RMON)•用于监控局域网的流量–错误诊断–规划网络–性能调整•工作在MAC层–只能监控局域网的情况–流量统计和分析(9组)•可以管理的设备:–路由器,交换机,集线器,服务器,主机7ApplicationsLayer6PresentationLayer5SessionLayer4TransportLayer3NetworkLayer2MACLayer(DLC)1PhysicalLayerISOmodel}RMONMIB}MIB扩展和RMON2RMON简介TokenRingOrderGroupToRMON2EventsFiltersPacketCaptureTrafficMatrixHostTopNHostsAlarmsHistoryStatisticsRootisoorgdodInternetMgmtMIBRMONRMONMIBGroups(RFC1757)报警确定阀值历史进行趋势分析的区间抽样统计数据统计累计的局域网通信和故障统计数据矩阵所追踪的两个设备之间的对话HostTopN按MAC地址排序的统计数据过滤器数据包选择机制事件对报警信号所引起的操作进行控制的机制包捕获数据包收集和上载机制令牌环针对令牌环设备的特殊参数，包括环站、环站次序、环站配置、源路由统计数据主机由介质访问控制地址(MAC)组成的统计数据(ProbeConfigurationApplicationLayerMatrixApplicationLayerHostNetworkLayerMatrixNetworkLayerHostAddressMappingProtocolDistributionProtocolDirectoryToRMON1UserHistoryRootisoorgdodInternetMgmtMIBRMONRMONConformanceRMON2MIBGroups(RFC2021)网络管理的构成NMS.日常操作.设备管理.预测管理.运行开销什么是网络管理?错误安全计帐配置性能网络管理的OSI模型增加删除变更记录网络的配置配置管理AnalyzeperformanceandtrendsBaselinenetworkperformance性能管理IdentifyproblemsIsolateproblemsResolveproblems错误管理NetworkAccessAccessDeniedPhysicalAccess安全管理TracknetworkresourcesAnalyzenetworkresources记账管理Optivity网管工作站HubAgentDevicePortispartitioned,auto-partitiontrapissent错误管理系统AlertNetworkManagerNetworkReplyTrapsPollFaultsStateChangesFaultCorrelatorInterpretsEventsFaultManagementSystemdomain.tableTrapServerDomainRelaySuperAgentApplicationDaemonsSNMPRequestsSNMPResponsesRawTrapsOptivityDatabaseOptivityStationSuperAgenthostSNMPdevicesDomain&TrapRegistrationtrap.tableEHANetworkAtlasManagementPlatformTrapServerFaultCorrelatorTrapServerFaultRecorderStateRecorderOptivityStationFaultDatabaseOptivityDatabasePlatformEventlogFaultSummarySuperPingICMPPingSuperAgenthostRawTrapsMetaTrapsSNMPDevicesOptivityFaultManagementApplicationsUsingtheFaultManagementSystemNoYesNoYesFixProblemVerifyifproblemstillsexistsUseFaultSummarytoidentifycauseofproblemNetworkproblemidentified?UseEnterpriseHealthAdvisortomonitorhealthofnetwork.EnterpriseLevelFaultManagementNetworkAtlas网络排错的基本原则网络变得复杂IBM3274Dial-on-DemandSDLCT1/E1XWindowsASCIIProtocolTranslatorLATHostPoint-to-PointSMDS,X.25,FrameRelayIBMMainframewithFEPFDDIDialBackupDialBackupLoadSharingTokenRingTokenRingLANSwitchLANSwitchInter-SwitchLink(ISL)VLANsTokenRing解决问题的流程结束确定问题观察结果重复过程收集信息考虑可能性实施解决方案解决问题文档资料现象消失了吗?yesno开始建立解决方案TCP/IP网络的排错TCP/IP网络的问题定位•IsolatingaconnectionproblembetweenalocalandremotehostFixremotehostconfigurationYYNNNFixanyrouterconfigurationproblems,andanyLANproblemsFixanyrouterconfigurationproblems,LANorWANproblemsLocalhostconfigurationOK?YNFixanyproblemswithaddress,subnetmask,defaultgatewayCanyoupinglocalrouter?Canyoureachallrouterstoremotehost?RemotehostconfigurationOK?Symptom:UsersCanAccessSomeHostsbutNotOthers•CanhostAconnecttohostC?•CanhostAconnecttohostB?•CanhostDconnecttohostC?HostD10.1.2.7255.255.255.0HostC10.1.2.8255.255.0.0HostB10.1.1.6255.255.0.0HostA10.1.1.5255.255.255.0Ethernet110.1.2.1255.255.255.0Ethernet010.1.1.1255.255.255.0subnet2subnet1Symptom:UsersCannotConnectWhenOneRedundantPathIsDownSerialZSerialXSerialYB1C2C1NetC1(Subnet)NetC2(Subnet)MajorNetwork:NetCMajorNetwork:NetBProblemIsolationinWindowsNT/95TCP/IPNetworks•IsolatingproblemswithWindowsIPconnectionsFixanyproblemswithTCP/IPconfigurationoraddressresolution,theHostsfile,theLMHostsfile,WINS,ARP,DNSproblems(orsomeotherWindowsnetworkedservice)YYNNFixanyproblemswithrouterinterface,configuration,oraccesslistsFixanyproblemswiththeIPaddressing,subnetting,defaultgatewayroutetable,orARPcacheLocalhostconfigurationOK?YNFixanyproblemswithlocaladdress,subnetmask,defaultgateway,orDHCPsetup,andtargetaddressesRouterconfigurationOK?NNTServerconfigurationOK?CanyouconnectusingIPaddresses?Symptom:BrowserDoesNotShowAllNetworkResourcesHostD10.1.2.7255.255.255.0MasterBrowserNTServerC10.1.2.8255.255.0.0MasterBrowserHostB10.1.1.6255.255.0.0HostA10.1.1.5255.255.255.0MasterBrowserEthernet110.1.2.1255.255.255.0Ethernet010.1.1.1255.255.255.0subnet2subnet1HostBHostAHostCHostAHostBTCP/IP现象和问题可能的问题HostcannotaccessoffnethoststhroughrouterHostcannotaccesscertainnetworksthroughrouter现象NodefaultgatewayspecifiedonlocalhostMisconfiguredsubnetmaskonlocalhostRouterbetweenhostsisdownNodefaultgatewayspecifiedonlocalhostMisconfigured*accesslistDiscontiguousnetworkduetopoordesignorlinkfailure*Beawarethattheaccesslistmightbeconfiguredcorrectly.Itmightbeintentionalthatuserscanaccesssomehostsornetworks,butnotothers.Use