Network ManagementChapter 3SNMP and MIBCOMP4690,byDrXiaowenChu,HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Network Management Chapter 3 SNMP and MIB
OutlineSNMPv1: Simple Network ManagementProtocolSMl: Structure of Management InformationMiB: Management Information BaseSNMPv3COMP4690,byDrXiaowenChu,HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Outline ⚫ SNMPv1: Simple Network Management Protocol ⚫ SMI: Structure of Management Information ⚫ MIB: Management Information Base ⚫ SNMPv3
SNMPy1 Packet SNMPv1 packet has the formVersionCommunityNameProtocolDataUnit(PDU).Versiontheversion of SNMPSNMPv1 is"O"inversionfieldCommunitynamelikeapassword Agent can control who can access what Sent as plaintext, so not secureImprovedbySNMPv3COMP4690,byDrXiaowen Chu,HKBU
COMP4690, by Dr Xiaowen Chu, HKBU SNMPv1 Packet ⚫ SNMPv1 packet has the form Version Community Name Protocol Data Unit (PDU) ⚫ Version ⎯ the version of SNMP ⚫ SNMPv1 is “0” in version field ⚫ Community name ⎯ like a password ⚫ Agent can control who can access what ⚫ Sent as plaintext, so not secure ⚫ Improved by SNMPv3
SNMPV1PDUSNMP has different types of packets, each withdifferent format.PDU for Get-Request, Get-Next-Request and Set-Requesthas fields:RequestErrorErrorVarBindListIDIndexStatusRequestIDaninteger,likeasequencenumberErrorstatuserrorinGet-ResponseErrorindexan integer which identifies the firstvariable in VarBindList that caused errorCOMP4690,byDrXiaowen Chu,HKBU
COMP4690, by Dr Xiaowen Chu, HKBU SNMPv1 PDU ⚫ SNMP has different types of packets, each with different format. ⚫ PDU for Get-Request, Get-Next-Request and Set-Request has fields: ⚫ Request ID ⎯ an integer, like a sequence number ⚫ Error status ⎯ error in Get-Response ⚫ Error index ⎯ an integer which identifies the first variable in VarBindList that caused error Request Error Error VarBindList ID Status Index
SNMPV1PDUErrorstatusO=noError1=tooBig (PDUhastoo manybytes)2= noSuchName (no object with requested name 3 = badValue (invalid no. for PDU type)4 = readOnly (incorrect implementation of SNMP)5= genErr (any other error)COMP4690,byDrXiaowen Chu,HKBU
COMP4690, by Dr Xiaowen Chu, HKBU SNMPv1 PDU ⚫ Error status ⚫ 0 = noError ⚫ 1 = tooBig (PDU has too many bytes) ⚫ 2 = noSuchName (no object with requested name) ⚫ 3 = badValue (invalid no. for PDU type) ⚫ 4 = readOnly (incorrect implementation of SNMP) ⚫ 5 = genErr (any other error)