19-1©2005 Raj JainCSE473sWashington University in St. LouisNetwork Network Management Management (SNMP)(SNMP)Raj Jain Washington UniversitySaint Louis, MO [email protected] slides are available on-line at:http://www.cse.wustl.edu/~jain/cse473-05/19-2©2005 Raj JainCSE473sWashington University in St. Louisq Network Managementq SNMPq Management information base (MIB)q ASN.1 Notationq SNMPv2q SNMPv3Overview19-3©2005 Raj JainCSE473sWashington University in St. LouisNetwork ManagementNetwork Managementq Management = Initialization, Monitoring, Controlq Manager, Agents, andManagement Information Base (MIB)NetworkMIBAgentNetworkManagementStationMIBAgentMIBAgent19-4©2005 Raj JainCSE473sWashington University in St. LouisSNMPSNMPq Based on Simple Gateway Management Protocol (SGMP) –RFC 1028 – Nov 1987q SNMP = Simply Not My Problem [Marshall Rose]Simple Network Management Protocolq RFC 1058, April 1988q Only Five commandsCommand Meaningget-request Fetch a valueget-next-request Fetch the next value (in a tree)get-response Reply to a fetch operationset-requestStore a valuetrap An event19-5©2005 Raj JainCSE473sWashington University in St. LouisManagement Information BaseManagement Information Baseq MIBs follow a fixed naming and structuring convention ⇒ Structure of Management Information (SMI)q These conventions were adopted from Common management Information Protocol (CMIP) designed by ISOq All names are globally uniqueq All nodes of the name tree are assigned numeric values by standards authoritiesiso.org.dod.internet.mgmt.mib.ip.ipInReceives1.3.6.1.2.1.4.3q Tables rows are referenced by appending the index19-6©2005 Raj JainCSE473sWashington University in St. LouisMIB (Cont)MIB (Cont)q All names are specified using a subset of Abstract Syntax Notation (ASN.1)q ASN.1 specifies notation (that humans can read) and encoding (representation and ranges)q Only INTEGER, OCTET STRING, OBJECT IDENTIFIER, NULL typesq Only SEQUENCE, SEQUENCE OF, CHOICE constructors19-7©2005 Raj JainCSE473sWashington University in St. LouisGlobal Naming HierarchyGlobal Naming Hierarchyfddimib (73)fddi (15)dod (6)internet (1)directory (1) mgmt(2) experimental (3)private (4)mib (1)system (1) interfaces (2) transmission(10)ccitt(0) iso (1) joint-iso-ccitt (2)standard (0)iso9314 (9314)fddiMIB (1)org (3)fddi (8)19-8©2005 Raj JainCSE473sWashington University in St. LouisVariable Category MeaningsysUpTime system Time since last rebootifNumber interfaces # of InterfacesifMTU interfaces MTUipDefaultTTL ip Default TTLipInReceives ip # of datagramsreceivedipForwDatagrams ip # of datagramsforwardedicmpInEchos icmp # of Echo requestsreceivedtcpRtoMin tcp Min retrans timetcpMaxConn tcp Max connectionsallowed19-9©2005 Raj JainCSE473sWashington University in St. LouisMIB Definition: ExampleMIB Definition: ExampleipAddrTable ::= SEQUENCE of ipAddrEntryipAddrEntry ::= SEQUENCE {ipAdEntAddr ipAddress,ipAdEntIfIndex INTEGER,ipAdEntNetMask ipAddress,ipAdEntBcastAddr ipAddress,ipAdEntReasmMaxSize INTEGER (0..65535)}ipAddrEntry {ipAddrTable 1}ipAdEntNetMask {ipAddrTable 3}19-10©2005 Raj JainCSE473sWashington University in St. LouisExample of Network ManagementExample of Network ManagementRouter(Agent)Router(Agent)Router(Agent)Management Server(Manager)AgentAgent19-11©2005 Raj JainCSE473sWashington University in St. LouisSNMPv1 ConfigurationSNMPv1 Configurationq Manager sends request to UDP port 161. Agents send traps to UDP port 16219-12©2005 Raj JainCSE473sWashington University in St. LouisRole of SNMP v1Role of SNMP v119-13©2005 Raj JainCSE473sWashington University in St. LouisSNMPv2SNMPv2q Improved security: authentication and integrity using Data Encryption Standard (DES)q inform request ⇒ Multiple manager coordinationLocking mechanisms prevent multiple managers from writing at the same timeq get bulk ⇒ Better table handlingq Confirmation option for Traps ⇒ Agents can ensure that trap was received correctly.q New Error codes: noSuchName, badValue, readOnlyq Reference: RFC 1441, April 1993 and more19-14©2005 Raj JainCSE473sWashington University in St. LouisSNMPv3SNMPv3q Security update of SNMPv2q Authentication: Message authentication code with a shared secret keyq Privacy: Encryption using a shared secret keyq Access Control: Each manager can have a different set of read/write permission for various component of MIBq Ref: RFC 2570, April 1999 and more19-15©2005 Raj JainCSE473sWashington University in St. LouisSummarySummaryq Management = Initialization, Monitoring, and Controlq SNMP = Only 5 commandsq Standard MIBs defined for each objectq Uses ASN.1 encodingq SNMPv2 fixed issues with bulk requests and simple securityq SNMPv3 added security19-16©2005 Raj JainCSE473sWashington University in St. LouisReading AssignmentReading Assignmentq Read section 22.3 of Stallings’ 7theditionq Try to answer review questions 22.6 through 22.9 and problem 22.5. There is no need to submit the