Simple Network Management Protocol (SNMP) is a network-management protocol used almost exclusively in TCP/IP networks. SNMP provides a means to monitor and control network devices, and to manage configurations, statistics collection, performance and security on a network. SNMP uses a distributed architecture consisting of entities called “managers” and “agents”.
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 (see Figure 4).
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.
In Niagara, the SNMP driver uses the standard NiagaraAX network architecture. See “About Network architecture” in the NiagaraAX-3.x Drivers Guide for more details. The SNMP driver provides the components necessary to integrate SNMP devices and data into the Niagara environment. This driver currently supports SNMP versions 1 and 2. The SNMP Driver can be used to set up and serve both the manager and the agent applications:
-
SNMP Manager
A manager is an SNMP application that generates queries to SNMP agent applications and receives traps from SNMP agent applications.
The Niagara SNMP Driver can be set up as a “Manager” (or “Client”) to monitor a network of SNMP devices. This configuration includes a view for compiling MIB files to determine the data that is contained within an SNMP device. Once “discovered”, the data points can be set up to monitor and control the SNMP devices. The driver can also handle receiving and processing unsolicited SNMP Trap Messages.
-
SNMP Agent
An agent is an SNMP application that responds to queries from SNMP manager applications. The SNMP agent is responsible for retrieving and updating local management information based on the requests of the SNMP manager. The agent also notifies registered managers when significant events or traps occur.
The Niagara SNMP Driver can be set up to act as an SNMP agent on a network to serve information to an outside SNMP manager. The SNMP Agent is typically configured to expose Niagara data to the SNMP data requests and can also generate SNMP v1 trap messages based on Niagara alarms. Every SnmpNetwork component has a “Local Device” component. The local device is a frozen slot on the SnmpNetwork component that can be “disabled” but cannot be removed.