It is important to provide some form of management on a network to control the resources available to meet real-time, operational, and Quality of Service requirements at a reasonable cost. This management includes deployment, hardware integration and coordination, software, and human elements with a view to testing, polling configuration, analysis, and control of the network. To achieve this, one of the mechanisms is the Simple Network Management Protocol or SNMP.
The devices managed on a network are used to convey objects whose data is stored in the Management Information Base or MIB. These objects are structured in a uniform fashion using the Structure of Management Information (SMI). The purpose of SMI is to ensure data stored in the MIB is in an unambiguous format. The SMI is used to identify various data types, define data objects, and the grouping of related objects in a MIB module. The MIB module is specified under the SMI module identity. These modules are from the content stored in the MIB.
The overall function of SNMP, therefore, is to manage object information and convey commands to manipulate the objects. The process of conveying MIB information is achieved through two ways, namely, request/response and trap modes. In the request/response mode, the user device can request the MIB information from a router, and the response is the router sends the data requested. The other option is the trap mode, in which the router simply sends a trap message containing this information to the user device. The trap mode is used to pass on information to the device about an exceptional event.