Manajemen Jaringan, Sukiswo ST, MT 1 SNMP Management Information Sukiswo

2 Table of Contents  Structure of Management Information –Overview –Meanings of MIB –SNMP MIB Structure –MIB Object Syntax –Defining MIB Objects –Defining MIB Tables Manajemen Jaringan, Sukiswo ST, MT

3 Overview of SNMP SMI  Structure of Management Information (SMI) –RFC 1155 (Full Standard) –defines the general framework for defining SNMP MIBs –describes how the managed objects (MOs) can be defined in the MIB, data types and values MOs can have and how MOs are named  SNMP SMI uses a subset of ASN.1  SNMP MIB can store only simple data types –scalars –2-dimensional arrays of scalars Manajemen Jaringan, Sukiswo ST, MT

4 Meanings of MIB  a MIB - a single MO definition  the MIB - the union of all MO definitions  MIB - the actual values of management information in a system a document containing definitions of management information a module written in a computer parsable form containing definitions MIB module the MIB a MIB a managed system a system's MIB management information 123 MIB document Manajemen Jaringan, Sukiswo ST, MT

5 MIB Structure  all MOs are structured hierarchically  Leaf objects in the tree are real MOs  Each MO has an OBJECT IDENTIFIER (OID) root joint-iso-ccitt(2)iso(1)ccitt(0) org(3) dod(6) internet(1) mgmt(2) experimental(3) private(4) snmpv2(6) mib-2(1) enterprises(1) Manajemen Jaringan, Sukiswo ST, MT

6 Object Identifier (OID)  uniquely identifies an MO in the MIB internet OBJECT IDENTIFIER : = { iso(1) org(3) dod(6) 1}  can be written as { } or  OID for tcpConnTable is iso org dod internet mgmt mib-2 tcp tcpConnTable  What is the OID for the object ifInOctets? (Hint: see MIB-II interfaces group, Fig 5.1 & 6.2) Manajemen Jaringan, Sukiswo ST, MT

7 Managed Object Syntax  ASN.1 notation is used to define MOs and the entire MIB structure Universal Types –INTEGER –OCTET STRING –NULL –OBJECT IDENTIFIER –SEQUENCE –SEQUENCE-OF Application-wide Types –Networkaddress –Ipaddress –Counter –Gauge –Timeticks –Opaque Manajemen Jaringan, Sukiswo ST, MT

8 Defining Managed Objects  the macro definition used for SNMP MIBs was initially defined in RFC 1155 (SMI) and later expanded in RFC 1212 (Concise MIB Definition)  RFC 1155 is used for defining MOs in MIB-I  RFC 1212 is used for defining MOs in MIB-II which is implemented in most SNMP agents today  OBJECT TYPE MACRO definition is used to define MOs –see Figure 5.3 (Macro for Managed Objects - RFC 1212) –see Figure 5.4 (SMI - RFC 1155) Manajemen Jaringan, Sukiswo ST, MT

9 Defining MO Tables  SNMP MIB structure is a simple 2-dimensional table with scalar-valued entries  A table typically consists of a SEQUENCE OF some entries  A table entry typically consists of a SEQUENCE that includes a number of scalar elements  See Figure 5.6 (MIB-II Specification of TCP Connection Table - RFC 1213) Manajemen Jaringan, Sukiswo ST, MT

10 Encoding MOs  Objects in the MIB are encoded using the basic encoding rules (BER)  BER is a widely used and standard encoding scheme  READING – Read Chapter 5 Manajemen Jaringan, Sukiswo ST, MT