SNMP provides a simple level of router monitoring and management via various protocols, such as UDP, IPX, or IP. Simple is an important word to remember in any discussion of SNMP. SNMP is nothing if not simple. First of all, it only supports four commandsGET, GETNEXT, SET, and TRAP. The first two provide access to reporting information, and the third allows you to remotely control certain functions of the routers. The TRAP command enables devices to report on problems or events within the device.
Network devices supply their specific information via a Management Information Base (MIB). This data, which defines the device to the SNMP manager, is fed to the SNMP Management Station, which in turn identifies each device and stores its specific data. All SNMP-compliant devices are managed from this station. Each device runs an SNMP Agent that provides the client side of the operations for the device. When the Management Station requests a GET command for port conditions, the agent returns that information.
SNMP is not meant to manage all network devices to a high level of detail. This is simple, day-to-day management that allows you to pay close attention to your devices without having to load half a dozen management interfaces. SNMP uses the UDP transport protocol for sending messages.