1. Internet Standard Management Framework w.lilakiatakun

2. Internet Standard Management Framework • Definitions of network management objects, known as MIB objects • A data definition language, known as SMI (structure of Management Information) • Define data types, an object model and rules for writing and revising management information • A protocol, SNMP (Simple Network Management Protocol) • For conveying information between a manager and agent • Security and administration capabilities • Major enhancement in SNMPv3 over SNMPv2

3. SMI (Structure of Management Information)

4. SMI (Structure of Management Information) • SMI is the language used to define the management information residing in a managed entity • SMI(v2) for SNMPv3 are RFC 2578,RFC2579, RFC2580 • SMI is based on the ASN.1 (Abstract Syntax Notation One, ISO1987)

5. SMI base data types

6. Object types • Scalar – object types that will be instantiated only once in an agent • Columnar – object types that can be instantiated multiple times • It impose a tabular structure on an ordered collection of MIB objects using the SEQUENCE OF construct

7. SMI higher-level Constructs • SMI provides higher-level language constructs • The OBJECT-TYPE construct is used to specify the data type, status and semantics of a managed object • The MODULE-IDENTITY construct allows related objects to be grouped together within a module • The NOTIFICATION-TYPE construct is used to specify information regarding SNMPv2-Trap and InformationRequest messages generated by an agent or a managing entity

8. The OBJECT-TYPE construct • SYNTAX – specify the basic data type associated with the object • MAX-ACCESS – specify whether the managed object can be read, be written, be created. • STATUS – indicate whether the object definition is current and valid, obsolete or deprecated (obsolete but implement for backward compatibility) • DESCRIPTION – textual definition of the object

9. OBJECT-TYPE construct • Page 796

10. MODULE-IDENTITY construct

11. Management Information Base

12. Categories of management information • State information • Physical configuration information • Logical configuration information • Historical information

13. State information • It is about the current state of physical and logical resources along with any operational data • Whether the device is functioning properly • What current alarm conditions • How long the system has been up • It is most relevant for monitoring a network • Frequent and rapid changecharacteristics • It can be retrieved but cannot be modified (owned by the devices) • Not to cache in a management app.

14. Physical configuration information • It is about how the managed devices is physically configured • The device type • MAC address • Serial number of devices • It can be retrieved but cannot be modified (owned by the devices) • Not change frequently, management app. might cache in its database

15. Logical configuration information • It is about the parameter setting and configured logical resources on the device • IP addresses • Protocols • It is controlled and can be changed by the management app. • It might be cached in a management app. but need to be aware of many app. usage • It can be divided • Start up configuration information • Transient (running) configuration information

16. Historical information • It includes snapshots of performance-related state information for a long period of time • Packet counts for each 15 minute interval over 24 hours • It also includes logs of various types of events • Firewall log of recent remote connection

17. MIB (Management Information Base) • It represents as a collections of managed objects that form a virtual information store • MIB is not the same as database • MIB actually connects to the real world and simply offers a view of it

18. What is contained in MIB • Many individual pieces of management information about the managed entity • Individual pieces of management information are referred as “managed objects” • Physical • Ports/ interfaces / line card • Logical • Version of installed software • Protocols • Features of communication services

19. MIB and Managed Objects

20. Arrangement of MIB • It is arranged into a conceptual tree • Every definition in a MIB module is represented by a node in that tree • Each node is named as the “ object identifier (OID)” • OID consists of a sequence of integer • OID (internet ) = 1.3.6.1

21. MIB-2 Object Identifier Tree • Fig 9.3

22. An Example: MIB-2 RFC1213-MIB DEFINITIONS::= BEGIN mib-2 OBJECT IDENTIFIER ::= {mgmt 1} - Establish mib-2 as a new node underneath a supernode called mgmt inside the Internet object identifier tree - OID is 1.3.6.1.2.1

23. Groups in MIB-2 • Fig – page 193

24. MIB-2 naming structure • Fig 6-13

25. Example of modules • Fig page 194-195

27. Definition of object type • SYNTAX – using the universal and application -wide type such as • DisplayString with a maximum length 255 chars. • TimeTicks • ACCESS – specify whether the object is a parameter that can be set (read-write) or only read • Read-only/read-write/write-only/Not-accessible • Status – definition life cycle • Mandatory/optional (SMI v1) • Current/deprecated/obsolete (SMI v2) • Description – explanation of the object type • OID relative to containing node

28. Definition of a table (columnar) object

29. Definition of the rows of the table

30. TcpConnEntry data type • Fig 197

31. Sequence of Vs Sequence • The overall table consists of a SEQUENCE OF TcpConnEntry • One or more elements, all of the same type • Each row consists of a SEQUENCE that include 5 scalar elements • Fixed number of elements, possibly more than one type • Ex. Contains element of type INTEGER, IpAddress, INTEGER(..65535),IpAddress,INTEGER(..65535)

32. tcpConnState

34. tcpConnLocalAddresstcpConnLocalPort • Fig 198

35. tcpConnRemAddresstcpConnRemPort • Fig 199

36. Structure of SNMP MIB OID • Fig 6-14

37. Object identifier tree for MIB tables • Fig 6-15

38. Identification of instances • Scalar – To access instance of scalar object • add .0 to the OID • Instance of sysUPtime is 1.3.6.1.2.1.1.3.0 • Columnar – To access instance of columnar object • add index to the OID Ex. Instance of TcpConnState (row1) is 1.3.6.1.2.6.13.1.1.167.8.15.92.227.176.15.53.216.228 Index of TcpConnEntry • Local address – 167.8.15.92 • Local port – 227 • Remote address – 176.15.53.216 • Remote address – 228

39. Subtree under MIB-II (RFC1213) (1) • system(1) : overall information about the system • interfaces(2) : information about the interfaces • at(3) : (Address translation) • ip(4) : information related to the implementation of IP

40. Subtree under MIB-II (2) • tcp(5) : information related to the implementation of TCP • udp(6) : information related to the implementation of UDP • egp(7) : information related to the implementation of EGP • dot3(8) : information related to Ethernet protocol at each interface • snmp(9) : information related to the implementation of SNMP

41. System group (1)

42. System group (2) • Table 6-1

43. System Group (3) • sysServices(7) – has a value that is interpreted as a 7-bit code • Each bit corresponds to a layer in TCP/IP or OSI architecture • Ex. Host offering app. services would have binary of 1001000 • It means services are provided for layer 4 (transport layer) and layer 7 (application layer)

44. System Group (4) • sysUptime (3) indicate amount of time since the network management portion of the system was last reinitiated. • Determine how much the counters have changed over a specific time interval • Fault monitoring : current value < most recent value

45. Interface Group (1)

47. Interfaces Group(2) • ifPhysAddress(6) : physical address • For all LAN, it contains MAC address • ifOperStatus(8) : current operational status • Up (1) /down (2) • ifSpeed (5) : current capacity of interface in bit per second • To detect congestion • Measure total number of octets into or out of the interface • The queue length for output of the interface

48. Address Translation Group (1)

49. Address Translation Group (2) • Consists of a single table • Each row in the table corresponds to one of the physical interface of the system • The row provide a mapping from a network address to a physical address

50. Address Translation Group (3)