3. The Simple Network Management Protocol
(SNMP) is an application layer protocol used to
manage network resources. This standardization
gives network administrators the ability to
monitor network performance.
Defines the format of packets exchanged between
a manager and an agent.
It reads and changes the status (values) of
objects(variables) in SNMP packets.
September 4, 2013 3
INTRODUCTION
5. Here is a very simplified picture.
Network manager contact to the agent through
TCP/IP protocol.
The agent resides in the managed devices and this
agent have some agent variables which should be
available to this manger for monitoring.
September 4, 2013 5
CONCEPT
6. AGENT:
• A router or host that runs the SNMP server
program.
• Keep the performance information in a data base.
• Can send a trap to the manager if something
unusual occurs.
September 4, 2013 6
CONCEPT
7. MANAGER:
• A host that runs the SNMP client program.
• Has access to values in the agent database.
September 4, 2013 7
CONCEPT
8. A manager checks an agent by requesting
information that reflects the behaviour of the
agent.
A manager forces an agent to perform a task by
resetting values in the agent database.
An agent contributes to the management process
by warning the manager of an unusual situation
September 4, 2013 8
CONCEPT
11. This is the actual SNMP protocol itself.
It defines how information is exchanged between
SNMP agents and network management stations.
The SNMP protocol operations define the various
SNMP messages and how they are created and
used.
September 4, 2013 11
SNMP
12. SNMP transport mappings describe how SNMP
can be used over various underlying internetworks
such as TCP/IP,IPX and others.
It simply an application program that has a client
on the manager and a server on the agent.
September 4, 2013 12
SNMP
14. SMI defines the general rules for naming objects,
defining object type (including range and length),
showing how to encode object and values.
SMI does not define the number of objects, an
entity should manage or name the objects to be
managed or define the association between the
objects and their values.
September 4, 2013 14
SMI
15. To name objects.
To define the type of data that can be stored in the
object.
To show how to encode the data for transmission.
September 4, 2013 15
SMI FUNCTION
20. All objects managed by SNMP are given an object
identifier.
The object identifier always starts with 1.3.6.1.2.1.
September 4, 2013 20
OBJECT IDENTIFIER
24. Sequence (like structure)
• Combination of simple data types,not of same
type.
Sequence of (like array)
• Combination of simple data types all of same type.
September 4, 2013 24
STRUCTURED DATA TYPE
35. Five messages of SNMP
1.Get Request
->Sent by manager requesting specific data
from agent
2.Get Next Request
->Retrieves the next value of the next lexical
MIB variable.
3.Get Response
->Agent respond with data for get and set
requests from the manager.
September 4, 2013 35
SNMP MESSAGES
36. 4.Set Request
->Initializes or changes the value of network
element
5.Trap
->Alarm generated by an agent
September 4, 2013 36
SNMP MESSAGES
38. • Traps are unrequested event reports that are sent
to a management system by an SNMP agent
process
• When a trappable event occurs, a trap message is
generated by the agent and is sent to a trap
destination (a specific, configured network
address)
• Many events can be configured to signal a
trap, like a network cable fault, failing Hard
Drive, a “General Protection Fault”, or a power
supply failure
September 4, 2013 38
WHAT IS TRAP
39. • Traps can also be throttled -- You can limit the
number of traps sent per second from the agent
• Traps have a priority associated with them --
Critical, Major, Minor, Warning, Marginal,
Informational, Normal, Unknown
September 4, 2013 39
WHAT IS TRAP
40. (0).coldStart -agent has been booted
(1).warmStart -agent has been rebooted
(2).linkDown -interface has gone down
(3).Linkup -interface has come up
September 4, 2013 40
TRAP TYPES
43. September 4, 2013 43
COMMERCIAL SNMP APPLICATIONS
Here are some of the various SNMP Management products available today
•http://www.hp.com/go/openview/ HP OpenView
•http://www.tivoli.com/ IBM NetView
•http://www.novell.com/products/managewise/ Novell ManageWise
•http://www.sun.com/solstice/ Sun MicroSystems Solstice
•http://www.microsoft.com/smsmgmt/ Microsoft SMS Server
•http://www.compaq.com/products/servers/management/ Compaq Insight Manger
•http://www.redpt.com/ SnmpQL - ODBC Compliant
•http://www.empiretech.com/ Empire Technologies
•ftp://ftp.cinco.com/users/cinco/demo/ Cinco Networks NetXray
•http://www.netinst.com/html/snmp.html SNMP Collector (Win9X/NT)
•http://www.netinst.com/html/Observer.html Observer
•http://www.gordian.com/products_technologies/snmp.html Gordian’s SNMP Agent
•http://www.castlerock.com/ Castle Rock Computing
•http://www.adventnet.com/ Advent Network Management
•http://www.smplsft.com/ SimpleAgent, SimpleTester
44. Standardized
Universally supported
Extendible
Portable
Allows distributed management access
Light weight protocol
September 4, 2013 44
ADVANTAGES OF USING SNMP
45. TCP/IP protocol suite by Behrouz A. Forouzan.
Internetworking with TCP/IP,principles,protocols
and architectures by Douglas E. Comer.
Network management principles and practices by
mani Subhramanian.
http://en.wikipedia.org/wiki/Simple_Network_M
anagement_Protocol
http://www.erlang.org/doc/apps/snmp/snm
p.pdf
http://www.hit.bme.hu/~jakab/edu/litr/SNMP/s
nmp_basics.pdf
September 4, 2013 45
REFERENCES