1. Jaringan Telekomunikasi, Sukiswo ST, MT Sukiswo sukiswok@yahoo.com
SNMP Version 2 (SNMPv2)
Sukiswo
Manajemen Jaringan, Sukiswo ST, MT

2. Manajemen Jaringan, Sukiswo ST, MT
Table of Contents
The Birth of SNMPv2
SNMPv2 RFCs
SNMPv2 Enhancements
SNMPv2 Protocol Operations
SNMPv2 Coexistence with SNMPv1
Manajemen Jaringan, Sukiswo ST, MT 3

3. Manajemen Jaringan, Sukiswo ST, MT
The Birth of SNMPv2
a major problem with SNMP is the lack of security
secure SNMP was proposed (July 1992) to solve this problem in SNMP
Simple Management Protocol (SMP) was also proposed (July 1992) to extend the SNMP functionality
secure SNMP + SMP = SNMPv2 (March 1993)
a major security flaw was detected in this proposal and the security aspects were dropped and the result is community-based SNMPv2 (Jan. 1996)
Manajemen Jaringan, Sukiswo ST, MT

4. Manajemen Jaringan, Sukiswo ST, MT
SNMPv2 RFCs
RFC 1901 (experimental)
Introduction to Community-based SNMPv2
RFC 1902 (draft) -> RFC 2578 (standard)
Structure of Management Information for SNMPv2 (SMIv2)
RFC 1903 (draft) -> RFC 2579 (standard)
Textual Conventions for SMIv2
RFC 1904 (draft) -> RFC 2580 (standard)
Conformance Statements for SMIv2
Manajemen Jaringan, Sukiswo ST, MT

5. Manajemen Jaringan, Sukiswo ST, MT
SNMPv2 RFCs (cont’d)
RFC 1905 (draft)
Protocol Operations for SNMPv2
RFC 1906 (draft)
Transport Mappings for SNMPv2
RFC 1907 (draft)
Management Information Base for SNMPv2
RFC 1908 (draft)
Coexistence between Version 1 and Version 2 of the Internet-standard Network Management Framework
Manajemen Jaringan, Sukiswo ST, MT

6. SNMPv2 Key Enhancements
SMIv2 (a superset of SMIv1)
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 SMIv2
Manager-to-Manager Capability
for managing large, distributed networks
Protocol Operations
bulk management information retrieval
manager-to-manager communication
Manajemen Jaringan, Sukiswo ST, MT

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

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

9. Notification Type Example
coldStart NOTIFICATION-TYPE
STATUS current
DESCRIPTION
"A coldStart trap signifies that the
SNMPv2 entity, acting in an agent role, is
reinitializing itself and that its
configuration may have been altered."
::= { snmpTraps 1 }
-- From RFC 1907
Manajemen Jaringan, Sukiswo ST, MT

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

11. Module Identity Example
rmon MODULE-IDENTITY
LAST-UPDATED " 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:
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

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

13. Object Identity Example
snmpUDPDomain OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The SNMPv2 over UDP transport domain.
The corresponding transport address
is of type SnmpUDPAddress."
::= { snmpDomains 1 }
-- from RFC 1906
Manajemen Jaringan, Sukiswo ST, MT

14. Manajemen Jaringan, Sukiswo ST, MT
SNMPv2 MIB Access
Manajemen Jaringan, Sukiswo ST, MT

15. Manajemen Jaringan, Sukiswo ST, MT
SNMPv2 Operations
GetRequest - get the value for each listed object
GetNextRequest - get next value for each listed object
GetBulkRequest - get multiple values
Response - respond to manager request
SetRequest - set value for each listed object
InformRequest - send unsolicited information from a manager to another
SNMPv2-Trap - send unsolicited information from an agent to a manager
Manajemen Jaringan, Sukiswo ST, MT

16. SNMPv2 PDU Formats variable-bindings request id PDU type
request id
PDU
type
(a) GetRequest-PDU, GetNextRequest-PDU, SetRequest-PDU,
SNMPv2-Trap-PDU, InformRequest-PDU
error
index
status
(b) Response-PDU
max-
repetitions
non-
repeaters
(c) GetBulkRequest-PDU
valueN
nameN
. . .
value2
name2
value1
name1
(d) variable-bindings
community
version (1)
SNMPv2 Message
Manajemen Jaringan, Sukiswo ST, MT

17. Manajemen Jaringan, Sukiswo ST, MT
GetBulkRequest
used to minimize the exchanges required to retrieve a large amount of information
selection principle is the same as GetNextRequest
the next object instance in lexicographic order
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
non-repeaters and max-repetition fields are used to indicate the number of N and R variables
Manajemen Jaringan, Sukiswo ST, MT

18. Interpretation of GetBulkRequest Fields
name1 name nameN
nameN nameN+R
For first N variables:
provide one value each
(first lexicographic successor)
For last R variables:
provide M values each
(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

19. GetBulkRequest Example
GetBulkRequest (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.
Agent
(e.g, router) x Y
Table a TA TB TC
NMS
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

20. SNMPv2-Trap and InformRequest
is sent from an agent to a manager when an unusual event occurs
no response is required
InformRequest
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

21. Manajemen Jaringan, Sukiswo ST, MT
SNMPv2 PDU Sequences
Manager
Agent
GetRequest PDU
Response PDU
SetRequest PDU
GetNextRequest PDU
SNMPv2-Trap PDU
GetBulkRequest PDU
InformRequest PDU
Manajemen Jaringan, Sukiswo ST, MT

22. Manajemen Jaringan, Sukiswo ST, MT
PDU Comparisons
Manajemen Jaringan, Sukiswo ST, MT

23. Manajemen Jaringan, Sukiswo ST, MT
Transport Mappings
RFC 1906 specifies the mapping of SNMPv2 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
The SNMPv2 document states that UDP is the preferred mapping
Manajemen Jaringan, Sukiswo ST, MT

24. Coexistence by Means of Proxy Agent
SNMPv1
agent
SNMPv2
manager
SNMPv2 environment
SNMPv1 environment
GetRequest
GetNextRequest
SetRequest
GetBulkRequest
Response
GetResponse
SNMPv2-Trap
Trap
SNMPv2 manager-to-agent
PDUs
SNMPv1 manager-to-agent
SNMPv2 agent-to-
manager PDUs
SNMPv1 agent-to-
Manajemen Jaringan, Sukiswo ST, MT

25. Coexistence by Means of Bilingual Manager
(v1, v2)
SNMPv2
SNMPv1
agent
GetRequest, GetNextRequest,
SetRequest
GetResponse, Trap
InformRequest, Response
SNMPv2-Trap, Response
getRequest, getNextRequest
getBulkRequest, setRequest
Manajemen Jaringan, Sukiswo ST, MT

26. Manajemen Jaringan, Sukiswo ST, MT
Summary
SNMPv2 is a natural extension of SNMPv1
Key enhancements in SNMPv2 are:
more elaborate MIB specification capability (SMIv2)
Manager-to-Manager communication
Bulk information transfer
SNMPv2 failed to improve on security
More powerful but more complex than SNMPv1
SNMPv3 focuses on improving the security aspect
Manajemen Jaringan, Sukiswo ST, MT