SNMP Version 2 SNMPv 2 Sukiswo sukiswokyahoo com

SNMP Version 2 (SNMPv 2) Sukiswo sukiswok@yahoo. com Manajemen Jaringan, Sukiswo ST, MT 1

Table of Contents 4 The Birth of SNMPv 2 4 SNMPv 2 RFCs 4 SNMPv 2 Enhancements 4 SNMPv 2 Protocol Operations 4 SNMPv 2 Coexistence with SNMPv 1 Manajemen Jaringan, Sukiswo ST, MT 2

The Birth of SNMPv 2 4 a major problem with SNMP is the lack of security 4 secure SNMP was proposed (July 1992) to solve this problem in SNMP 4 Simple Management Protocol (SMP) was also proposed (July 1992) to extend the SNMP functionality 4 secure SNMP + SMP = SNMPv 2 (March 1993) 4 a major security flaw was detected in this proposal and the security aspects were dropped and the result is community-based SNMPv 2 (Jan. 1996) Manajemen Jaringan, Sukiswo ST, MT 3

SNMPv 2 RFCs 4 RFC 1901 (experimental) – Introduction to Community-based SNMPv 2 4 RFC 1902 (draft) -> RFC 2578 (standard) – Structure of Management Information for SNMPv 2 (SMIv 2) 4 RFC 1903 (draft) -> RFC 2579 (standard) – Textual Conventions for SMIv 2 4 RFC 1904 (draft) -> RFC 2580 (standard) – Conformance Statements for SMIv 2 Manajemen Jaringan, Sukiswo ST, MT 4

SNMPv 2 RFCs (cont’d) 4 RFC 1905 (draft) – Protocol Operations for SNMPv 2 4 RFC 1906 (draft) – Transport Mappings for SNMPv 2 4 RFC 1907 (draft) – Management Information Base for SNMPv 2 4 RFC 1908 (draft) – Coexistence between Version 1 and Version 2 of the Internet-standard Network Management Framework Manajemen Jaringan, Sukiswo ST, MT 5

SNMPv 2 Key Enhancements 4 SMIv 2 (a superset of SMIv 1) – provides more elaborate specification and documentation of managed objects and MIB modules • object type macros expanded (see Fig. 11. 1, 11. 2 & Table 11. 2) • creating and deleting conceptual rows in a table (as used in RMON) • notification definitions • information modules – new SNMP MIB definitions are defined using SMIv 2 4 Manager-to-Manager Capability – for managing large, distributed networks 4 Protocol Operations – bulk management information retrieval – manager-to-manager communication Manajemen Jaringan, Sukiswo ST, MT 6

Comparison of Data Types Manajemen Jaringan, Sukiswo ST, MT 7

Notification Type MACRO NOTIFICATION-TYPE MACRO : : = BEGIN TYPE NOTATION : : = Objects. Part “STATUS” Status “DESCRIPTION” Text Refer. Part VALUE NOTATION : : = value (VALUE Notification. Name) Objects. Part : : = “OBJECTS” “{“ Objects “}” | empty Objects : : = Object | Objects “, ” Object : : = value (Name Object. Name) Status : : = “current” | “deprecated” | “obsolete” Refer. Part : : = “REFERENCE” Text | empty Text : : = “““ string “““ END Manajemen Jaringan, Sukiswo ST, MT 8

Notification Type Example cold. Start NOTIFICATION-TYPE STATUS current DESCRIPTION "A cold. Start trap signifies that the SNMPv 2 entity, acting in an agent role, is reinitializing itself and that its configuration may have been altered. " : : = { snmp. Traps 1 } -- From RFC 1907 Manajemen Jaringan, Sukiswo ST, MT 9

Module Identity MACRO MODULE-IDENTITY MACRO : : = BEGIN TYPE NOTATION : : = “LAST-UPDATED” value (Update UTCTime) “ORGANIZATION” Text “CONTACT-INFO” Text “DESCRIPTION” Text Revision. Part VALUE NOTATION : : = value (VALUE OBJECT IDENTIFIER) Revision. Part : : = Revisions | empty Revisions : : = Revision | Revisions Revision : : = “REVISION” value (Update UTCTime) “DESCRIPTION” Text : : = “““ string “““ END Manajemen Jaringan, Sukiswo ST, MT 10

Module Identity Example rmon MODULE-IDENTITY LAST-UPDATED "9605270000 Z" ORGANIZATION "IETF RMON MIB Working Group" CONTACT-INFO "Steve Waldbusser (WG Editor) Postal: International Network Services 650 Castro Street, Suite 260 Mountain View, CA 94041 Phone: +1 415 254 4251 Email: waldbusser@ins. com DESCRIPTION "The MIB module for managing remote monitoring device implementations. This MIB module augments the original RMON MIB as specified in RFC 1757. " : : = { mib-2 16 } Manajemen Jaringan, Sukiswo ST, MT 11

Object Identity MACRO OBJECT-IDENTITY MACRO : : = BEGIN TYPE NOTATION : : = “STATUS” Status “DESCRIPTION” Text Refer. Part VALUE NOTATION : : = value (VALUE OBJECT IDENTIFIER) Status : : = “current” | “deprecated” | “obsolete” Refer. Part : : = “REFERENCE” Text | empty Text : : = “““ string “““ END Manajemen Jaringan, Sukiswo ST, MT 12

Object Identity Example snmp. UDPDomain OBJECT-IDENTITY STATUS current DESCRIPTION "The SNMPv 2 over UDP transport domain. The corresponding transport address is of type Snmp. UDPAddress. " : : = { snmp. Domains 1 } -- from RFC 1906 Manajemen Jaringan, Sukiswo ST, MT 13

SNMPv 2 MIB Access Manajemen Jaringan, Sukiswo ST, MT 14

SNMPv 2 Operations 4 Get. Request - get the value for each listed object 4 Get. Next. Request - get next value for each listed object 4 Get. Bulk. Request - get multiple values 4 Response - respond to manager request 4 Set. Request - set value for each listed object 4 Inform. Request - send unsolicited information from a manager to another 4 SNMPv 2 -Trap - send unsolicited information from an agent to a manager Manajemen Jaringan, Sukiswo ST, MT 15

SNMPv 2 PDU Formats version (1) community PDU SNMPv 2 Message request PDU 0 0 variable-bindings type id (a) Get. Request-PDU, Get. Next. Request-PDU, Set. Request-PDU, SNMPv 2 -Trap-PDU, Inform. Request-PDU error PDU request variable-bindings type id status index (b) Response-PDU nonmax. PDU request type id repeaters repetitions (c) Get. Bulk. Request-PDU name 1 value 1 name 2 value 2 . . . variable-bindings name. N value. N (d) variable-bindings Manajemen Jaringan, Sukiswo ST, MT 16

Get. Bulk. Request 4 used to minimize the exchanges required to retrieve a large amount of information 4 selection principle is the same as Get. Next. Request – the next object instance in lexicographic order 4 includes a list of (N + R) variable names in the variable-bindings list – the first N variables for retrieving single values – the next R variables for retrieving multiple values 4 non-repeaters and max-repetition fields are used to indicate the number of N and R variables Manajemen Jaringan, Sukiswo ST, MT 17

Interpretation of Get. Bulk. Request Fields name 1 name 2 . . name. N+1 . . name. N+R For first N variables: For last R variables: provide one value each provide M values each (first lexicographic successor)(first M lexicographic successors) L = number of names in variable-bindings field N = MAX [ MIN (non-repeaters, L), 0 ] M = MAX [ max-repetitions, 0 ] R=L-N Manajemen Jaringan, Sukiswo ST, MT 18

Get. Bulk. Request Example Get. Bulk. Request (non-repeaters = 2, max-repeaters = 6, X, Y, TA, TB, TC) Manager issues request with six variable names; for the first two variable (non-repeaters=2), a single value is requested; for the remaining variables six successive values (max-repeaters=6) are requested. NMS Agent (e. g, router) x Y Table a TA TB TC Agent returns single value for X, Y, and six rows of table a Response [X, Y, TA(1), TB(1), TC(1), TA(2), TB(2), TC(2), TA(3), TB(3), TC(3), TA(4), TB(4), TC(4), TA(5), TB(5), TC(5), TA(6), TB(6), TC(6) ] Manajemen Jaringan, Sukiswo ST, MT 19

SNMPv 2 -Trap and Inform. Request 4 SNMPv 2 -Trap – is sent from an agent to a manager when an unusual event occurs – no response is required 4 Inform. Request – is sent from a manager for passing information to an application running in another manager – Response PDU is used to acknowledge the request – for hierarchical or distributed management where multiple managers are involved Manajemen Jaringan, Sukiswo ST, MT 20

SNMPv 2 PDU Sequences Manager Agent Get. Requ est PDU onse Resp Manager PDU Agent Set. Requ est PDU Resp o DU nse P Manager Agent Get. Next Reques t PDU U PD onse p s e R Manager Inform. R Manager Agent Get. Bulk Reques t PDU e PDU ons Resp Manager Agent equest P DU e PDU rap Pv 2 -T PDU SNM ons Resp Manajemen Jaringan, Sukiswo ST, MT 21

PDU Comparisons Manajemen Jaringan, Sukiswo ST, MT 22

Transport Mappings 4 RFC 1906 specifies the mapping of SNMPv 2 onto the following transport protocols – User Datagram Protocol (UDP) – OSI Connectionless-Mode Network Service (CLNS) – OSI Connection-Oriented Network Service (CONS) – Novell Internetwork Packet Exchange (IPX) – Appletalk 4 The SNMPv 2 document states that UDP is the preferred mapping Manajemen Jaringan, Sukiswo ST, MT 23

Coexistence by Means of Proxy Agent SNMPv 2 environment SNMPv 1 environment Get. Request Get. Next. Request Set. Request Get. Bulk. Request SNMPv 2 manager Get. Next. Request SNMPv 2 manager-to-agent PDUs SNMPv 2 agent-tomanager PDUs Response Proxy Agent SNMPv 1 manager-to-agent PDUs SNMPv 1 agent-tomanager PDUs Get. Response SNMPv 2 -Trap Manajemen Jaringan, Sukiswo ST, MT 24

Coexistence by Means of Bilingual Manager Info SNMPv 2 manager Inf rm Re orm que st, Re spo nse Re qu est , R esp on p, P ra v 2 -T SNMPv 2 agent se e ons p s Re Bilingual manager (v 1, v 2) Get. Request, Get. Next. Request, Set. Request SNMPv 1 agent Get. Response, Trap t ues q e ext. R quest N t e t, g , set. Re s e u t Req eques t e g ulk. R B t ge Manajemen Jaringan, Sukiswo ST, MT 25

Summary 4 SNMPv 2 is a natural extension of SNMPv 1 4 Key enhancements in SNMPv 2 are: – more elaborate MIB specification capability (SMIv 2) – Manager-to-Manager communication – Bulk information transfer 4 SNMPv 2 failed to improve on security 4 More powerful but more complex than SNMPv 1 4 SNMPv 3 focuses on improving the security aspect Manajemen Jaringan, Sukiswo ST, MT 26