Snmp; Snmp Overview; Snmp Mechanism; Snmp Protocol Version - 3Com Baseline 2928 PWR Plus User Manual

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SNMP

SNMP Overview

Simple Network Management Protocol (SNMP) offers the communication rules between a
management device and the managed devices on the network; it defines a series of messages,
methods and syntaxes to implement the access and management from the management device to the
managed devices. SNMP has the following characteristics:
Automatic network management. SNMP enables network administrators to search and modify
information, find and diagnose network problems, plan for network growth, and generate reports on
network nodes.
SNMP shields the physical differences between various devices and thus realizes automatic
management of products from different manufacturers. Offering only the basic set of functions,
SNMP makes the management tasks independent of both the physical features of the managed
devices and the underlying networking technology. Thus, SNMP achieves effective management
of devices from different manufacturers, especially in small, high-speed and low cost network
environments.

SNMP Mechanism

An SNMP enabled network comprises Network Management Station (NMS) and agent.
An NMS is a station that runs the SNMP client software. It offers a user friendly interface, making it
easier for network administrators to perform most network management tasks.
An agent is a program on the device. It receives and handles requests sent from the NMS. Only
under certain circumstances, such as interface state change, will the agent inform the NMS.
NMS manages an SNMP enabled network, whereas agents are the managed network device. NMS
and agents exchange management information through the SNMP protocol.
SNMP provides the following four basic operations:
Get operation: NMS gets the value of a certain variable of the agent through this operation.
Set operation: NMS can reconfigure the value of one or more objects in the agent MIB
(Management Information Base) by means of this operation.
Trap operation: The agent sends traps to the NMS through this operation.
Inform operation: The NMS sends traps to other NMSs through this operation.

SNMP Protocol Version

Currently, SNMP agents support SNMPv3 and are compatible with SNMPv1 and SNMPv2c.
SNMPv1 uses community name for authentication. Community name defines the relationship
between an SNMP NMS and an SNMP agent. SNMP packets with community names that do not
pass the authentication on the device are simply discarded. A community name plays a similar role
as a key word and can be used to control access from NMS to the agent.
SNMPv2c uses community name for authentication. Compatible with SNMPv1, it extends the
functions of SNMPv1. SNMPv2c provides more operation modes such as GetBulk and
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