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Prestige 794M User’s Guide
111 Chapter 12 Device Management
Figure 79 SNMP Management Model
An SNMP managed network consists of two main components: agents and a manager.
An agent is a management software module that resides in a managed device. An agent
translates the local management information from the managed device into a form compatible
with SNMP. The manager is the console through which network administrators perform
network management functions. It executes applications that control and monitor managed
devices.
The managed devices contain object variables/managed objects that define each piece of
information to be collected about a device. Examples of variables include such as number of
packets received, node port status etc. A Management Information Base (MIB) is a collection
of managed objects. SNMP allows a manager and agents to communicate for the purpose of
accessing these objects.
SNMP itself is a simple request/response protocol based on the manager/agent model. The
manager issues a request and the agent returns responses using the following protocol
operations:
• Get - Allows the manager to retrieve an object variable from the agent.
• GetNext - Allows the manager to retrieve the next object variable from a table or list
within an agent. In SNMPv1, when a manager wants to retrieve all elements of a table
from an agent, it initiates a Get operation, followed by a series of GetNext operations.
• Set - Allows the manager to set values for object variables within an agent.
• Trap - Used by the agent to inform the manager of some events.
12.1.2.1 SNMPv3
SNMPv3 provides a secure environment for the management of systems and stations. It is
designed to protect against unauthorized modification of SNMP messages and operations by
using passwords (or community) to authenticate users. SNMPv3 provides user-based security
and view-based access control models.