ZyXEL Communications USG-300 - V2.20 ED 2, Руководство пользователя

Страница: 867 / 1149

Chapter 50 System
ZyWALL USG 300 User’s Guide
867
and version two (SNMPv2c). The next figure illustrates an SNMP management
operation.
Figure 575 SNMP Management Model
An SNMP managed network consists of two main types of component: agents and
a manager.
An agent is a management software module that resides in a managed device (the
ZyWALL). 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.