Simple Network Management Protocol; Overview; Snmp Entity; Snmp Agent - Foundry Networks NetIron M2404C User Manual

Foundry NetIron M2404C and M2404F Metro Access Switches

Simple Network Management Protocol

The Simple Network Management Protocol (SNMP) architectural model is a collection of network
management stations and network elements. Network management stations execute management
applications that monitor and control network elements. Network elements are devices that have
management agents responsible for performing the network management functions requested by
the network management stations. SNMP is used to communicate management information
between the network management stations and the agents in the network elements.
The SNMP system consists of an SNMP Manager, an SNMP Agent and a Management
Information Base (MIB). SNMP is an application-layer protocol that provides a message format for
communication between SNMP managers and agents.
Figure 1 displays the communication between an SNMP Agent and Manager.
The SNMP Manager sends requests to the SNMP Agent to get and set MIB values.
Communication among protocol entities is accomplished by the exchange of messages, each of
which is entirely and independently represented within a single UDP datagram. A message consists
of a version identifier, an SNMP community name, and a Protocol Data Unit (PDU). PDUs are the
packets that are exchanged in the SNMP communication. The SNMP Agent can send a notification
to notify the SNMP Manager of network conditions

Overview

SNMP Entity

An SNMP entity is an implementation of the SNMP architecture. Each SNMP entity consists of an
SNMP engine and one or more associated applications. An SNMP engine provides services for
sending and receiving messages, authenticating and encrypting messages, and controlling access to
managed objects. The SNMP engine is identified by the SNMP Engine ID. Applications use the
services of an SNMP engine to accomplish specific tasks. They coordinate the processing of
management information operations, and may use SNMP messages to communicate with other
SNMP entities.

SNMP Agent

An SNMP agent is a software module in a managed device responsible for maintaining local
management information and delivering that information to a manager via SNMP. A management
information exchange can be initiated by the manager or by the agent. The SNMP agent contains
MIB variables and these values can be requested or changed by the SNMP manager. The agent and
MIB reside on the device. The agent gathers data from the MIB. The Agent can respond to a
manager's request to get or set data.
Simple Network Management Protocol
Figure 1: SNMP Agent and Manager Communication
© 2008 Foundry Networks, Inc.
(Figure 1).
Configuring SNMP (Rev. 03)
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