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.
22.1.1Network Management System (NMS)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.
22.2 Configuring SNMP
Click Advanced Setting and SNMP to display the screen as shown next.
Figure 109 SNMP
172 | Chapter 22 SNMP |