The Simple Network Management Protocol (SNMP) is an application-layer communication protocol that provides a standardized method for managing network devices. The protocol is part of the TCP/IP protocol suite and uses UDP as its transport protocol.
In order to better appreciate how SNMP works, let’s begin by taking a look at the different components of an SNMP-based system – managed devices, agents, and network management systems.
- Managed Devices. A managed device is any piece of equipment that includes the ability to be managed via the SNMP protocol. Common examples include hubs, switches, routers, printers, and servers.
- Agents. A managed device includes a software module known as an agent. An agent implements the SNMP protocol on a device, allowing information about the device to be stored and retrieved. The terms “agent” and “managed device” are often used interchangeably when discussing SNMP.
- Network Management System. An SNMP Network Management System (NMS) is an application capable of monitoring and configuring SNMP managed devices. Examples of common NMSs include HP OpenView, SunNet Manager, and TNG Unicenter. These applications act as the focal point on an SNMP-managed network, where data is collected and configuration is carried out. In order to use SNMP to manage a network, at least one NMS must be present. NMSs are also sometimes referred to as consoles.