1. Simple Network Management Protocol

2. System and Network Management
Network Management : ability to monitor, control and plan the resources and components of computer system and networks
network management is a problem created by computer!
Goal of network management : keep networks up and running

3. Goal of Management Keeping Network Running
Maintaining Network performance
Reducing the Cost of Ownership

4. Architecture of Management
Components : Manager and agent
Manager : monitor and control the agents
Agents:
softwarte componentes residing in mangaed devices
responds to requests from manager
Network Management Protocol
protocol used to communicated between Manager and agents

5. agent
Manager
Network
Management
Protocol

6. SNMP
Easy-to-implement network management tool fot TCP/IP suite of protocols
SNMP : a collection of specification
actual protocols
definition of manage information
other related components

7. SNMP model SNMP components manager, agent and protocol SNMP Manager
Simple
Network
Management
Protocol

8. SNMP agent Software process that respons to SNMP protocol
resides in networks equipments such as hub, router, bridges or workstaions
Two basic roles
monitoring
controlling
Hardware
Components
Software
SNMP
agent
request
response

9. Components of SNMP agent
Prortocol Engine
request
response
Management
Information
Base
SNMP agent
Protocol engine : processing request from SNMP managers
receving request
decoding
servicing the request
sending response
Management Information Base (MIB) : collection of managed objects
each object is a data variable
standardized across system of a particular class

10. MIB objects
Each managed object has a unique identifier, called an MIB object identifier used for referencing an MIB object
ALL SNMP standards agents are required to support a standard set of managed objects
every MIB objects has an MIB definition that defines the managed object
MIB definitions are created using Abstract Syntax Notation One (ASN.1)
ASN.1 is a machine-independence data description (initially developed for use in OSI)
Only a subset of ASN.1 is used for SNMP
Rules for writing MIB definitions using ASN.1 are defined in Structure of Management Information (SMI)

11. SNMP protocol

12. SNMP operations Get Request Get Next Request Get Response Set Request
Trap

13. Variable binding
Each SNMP variable binding consists of a variable called obkject identifier (OID) and associated value
Object identifier Object value

14. MIB Tree
Structure for reference OID

15. ASN.1 Notation syscontact OID = 1.3.6.1.2.1.1.4
sysContact OBJECT-TYPE
SYNTAX DisplayString (SIZE (0..255))
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The textual identification of the contact
person for this managed node, together
with information on how to contact this
person."
::= { system 4 }
syscontact OID =
= iso.org.dod.internet.mgmt.mib-2.system.sycontact

16. Basic Encoding Rule Each field is encoded by BER Tag : variable type
Length
Contents
Tag : variable type
Length : length of contents
Contents : encoded data

17. Encoding example get request 1.3.6.1.2.1.1.1.0
sequence of 39 bytes
version 1
E 6D bytes of community string = #SNMP!
A0 1B request of 25 bytes
D 3E id =
error status =0
error index=0
30 0E sequence of length 14 bytes
30 0C sequence of length of 12 bytes
B object id of 8 bytes
05 00 null of 0 bytes
Version
community str.
PDU type
request ID
error status
error index
variable binding