Simple Network Management Protocol (SNMP) is the most popularly used protocol to manage network devices. It can facilitate the exchange of management information between network devices and an entity termed as network management station (NMS). Using SNMP with an NMS enables a network administrator to manage and monitor network devices from a single interface, which can typically support batch commands and automatic alerts.
SNMP operates at application layer of OSI model and uses UDP as its transport protocol. SNMP monitor is a widely used tool in network for an administrator to manage network performance, availability, solving problems, device statistics, technical information and moch more. Three versions of SNMP exist as SNMPv1, SNMPv2 and SNMPv3. All the three versions have number of features in common, but SNMPv3 includes authentication and encryption enhancements for packet protection over SNMPv2 and similarly over SNMPv2 over SNMPv1.
SNMP uses Protocol Data Unit(PDU) format as a standard for messages and each of the SNMP operations. Traditionally SNMP agents use these to send and receive information.
SNMP consists of
- SNMP Manager: The network management system (NMS) is a software platform that functions as a centralized console to which agents feed information. The NMS will actively request agents to send updates at regular intervals, and what a network manager can do with that information depends heavily on how feature-rich the NMS is.
- Managed Devices: These are the network devices and services upon which the agents run ranging from conventional network equipment like routers, switches and wireless access points to endpoints like printers, scanners and Internet of Things (IoT) devices..
- SNMP Agent: This software runs on the hardware or service being monitored, collecting data about disk space, bandwidth use and other important network performance metrics. When queried by the SNMP manager, the agent sends the requested information back to the management system.
- Management Information Database(MIB): This database is a text file (.mib) that itemizes and describes all objects on a particular device that can be queried or controlled using SNMP. Each MIB item is assigned an object identifier (OID).