ZyXEL Communications Vantage Service Gateway VSG-1200 V2 User Manual

VSG-1200 V2 User’s Guide

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Chapter 26 SNMP

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.

An NMS (Network Management System) is a management station that receives traps (the 
system alerts generated).

If no NMS is defined, then no traps are generated.

Click Advanced Settings and SNMP to display the screen as shown next.

Figure 119   SNMP