SNMP stands for Simple Network Management Protocol. It is an application-layer protocol within the Internet Protocol (IP) suite, designed specifically for monitoring and managing network devices on IP networks, such as routers, switches, servers, printers, and more.
SNMP Manager (Network Management Station, NMS): This is the central system that monitors and manages network devices. It sends requests to devices and receives responses or alerts (called traps) when certain events occur. SNMP Agent: This is software running on each managed device. The agent collects device-specific data, stores it in a database called the Management Information Base (MIB), and responds to queries from the SNMP manager. It can also proactively send alerts to the manager if predefined events happen. These are the network devices (like routers, switches, printers) that have SNMP agents installed and enabled. A virtual database on each device containing information about its configuration, performance, and operational status. Each piece of information in the MIB is identified by an Object Identifier (OID).
The SNMP manager sends Get requests to agents to retrieve information or Set requests to modify device configurations. Agents respond with the requested data or confirmation of changes. If a significant event occurs (like a device failure), the agent can send a trap message to the manager, alerting it immediately. SNMP typically uses UDP ports 161 (for general communication) and 162 (for traps).