System and Network Management Network Management : ability to - PDF document

1-1 System and Network Management •Network Management : ability to monitor, control and plan the resources and components of computer system and networks •network management is a problem created by computer! •Goal of network management : keep networks up and running http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-2 Goal of Management � Keeping Network Running � Maintaining Network performance � Reducing the Cost of Ownership http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

1-3 Architecture of Management � Components : Manager and agent � Manager : monitor and control the agents � Agents: � softwarte componentes residing in mangaed devices � responds to requests from manager � Network Management Protocol � protocol used to communicated between Manager and agents http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-4 Manager Network Management Protocol agent agent agent http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

1-5 SNMP � Easy-to-implement network management tool fot TCP/IP suite of protocols � SNMP : a collection of specification � actual protocols � definition of manage information � other related components http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-6 SNMP model � SNMP components SNMP Manager � manager, agent and protocol Simple Network Management Protocol SNMP SNMP SNMP agent agent agent http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

1-7 SNMP agent Software process that respons to � SNMP protocol Software Hardware resides in networks equipments � Components Components such as hub, router, bridges or workstaions Two basic roles � SNMP � monitoring agent � controlling request response http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-8 Components of SNMP agent SNMP agent Protocol engine : processing � request from SNMP managers Management � receving request Information Base � decoding � servicing the request � sending response Management Information Base � SNMP (MIB) : collection of managed Prortocol Engine objects request response � each object is a data variable � standardized across system of a particular class http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

1-9 MIB objects Each managed object has a unique identifier, called an MIB � object identifier used for referencing an MIB object ALL SNMP standards agents are required to support a � standard set of managed objects every MIB objects has an MIB definition that defines the � managed object MIB definitions are created using Abstract Syntax Notation � One (ASN.1) ASN.1 is a machine-independence data description (initially � developed for use in OSI) Only a subset of ASN.1 is used for SNMP � Rules for writing MIB definitions using ASN.1 are defined in � Structure of Management Information (SMI) http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-10 SNMP protocol http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

1-11 SNMP operations � Get Request � Get Next Request � Get Response � Set Request � Trap http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-12 Variable binding � Each SNMP variable binding consists of a variable called obkject identifier (OID) and associated value Object identifier Object value http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

Root 1-13 MIB Tree ccitt iso Joint-iso-ccitt 0 1 2 org � Structure for reference 3 OID dod 6 internet 1 directory mgmt experimental private 1 2 3 4 mib-2 enterprises 1 1 vender object system interfaces at ip icmp tcp udp egp transmission snmp 1 2 3 4 5 6 7 8 10 11 sysDesc ifNumber 1 1 http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-14 ASN.1 Notation sysContact OBJECT-TYPE SYNTAX DisplayString (SIZE (0..255)) ACCESS read-write STATUS mandatory DESCRIPTION "The textual identification of the contact person for this managed node, together with information on how to contact this person." ::= { system 4 } syscontact OID = 1.3.6.1.2.1.1.4 = iso.org.dod.internet.mgmt.mib-2.system.sycontact http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University

1-15 Basic Encoding Rule � Each field is encoded by BER Tag Length Contents � Tag : variable type � Length : length of contents � Contents : encoded data http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University 1-16 Encoding example � get request 1.3.6.1.2.1.1.1.0 30 27 sequence of 39 bytes Version 02 01 00 version 1 community str. 04 06 73 23 6E 6D 70 21 6 bytes of community string = #SNMP! PDU type A0 1B request of 25 bytes request ID 02 04 23 41 3D 3E id =591478078 error status 02 01 00 error status =0 error index 02 01 00 error index=0 variable binding 30 0E sequence of length 14 bytes 30 0C sequence of length of 12 bytes 06 08 2B 06 01 02 01 01 01 01 00 object id of 8 bytes 1.3.6.1.2.1.1.1.0 05 00 null of 0 bytes http://www.cpe.ku.ac.th/~nguan/resource/slide/network Department of Computer Engineering, Kasetsart University