SNMP Architecture

The SNMP agent exchanges network management information with SNMP manager software running on a network management system (NMS), or host. The agent responds to requests for information and actions from the manager. The agent also controls access to the agent's Management Information Base (MIB), the collection of objects that can be viewed or changed by the SNMP manager.

The SNMP manager collects information on network connectivity, activity, and events by polling managed devices.

Communication between the agent and the manager occurs in one of the following forms:

• Get, GetBulk, and GetNext requests—The manager requests information from the agent; the agent returns the information in a Get response message.
• Set requests—The manager changes the value of a MIB object controlled by the agent; the agent indicates status in a Set response message.
• Traps notification—The agent sends traps to notify the manager of significant events that occur on the network device.