Snmp - ZyXEL Communications NXC2500 User Manual

Chapter 24 System

24.11 SNMP

Simple Network Management Protocol is a protocol used for exchanging management information
between network devices. Your NXC supports SNMP agent functionality, which allows a manager
station to manage and monitor the NXC through the network. The NXC supports SNMP version one
(SNMPv1) and version two (SNMPv2c). The next figure illustrates an SNMP management operation.
Figure 168 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 NXC). 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.
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NXC2500 User's Guide