SNMP, the Simple Network Management Protocol, is an Internet standard protocol that collects and organizes information about managed devices on the IP network. These protocols also modify the information to change the device’s behavior.
The protocol is commonly used in network management systems to monitor network-attached devices for situations that demand administrative attention.
Components of SNMP
Managed Devices
These are the network devices that are being monitored and managed in an infrastructure. Managed devices can include routers, switches, servers, printers, and more.
SNMP Agents
The software modules that are installed on managed devices are known as SNMP agents. These agents collect and store management information and make it available to the SNMP manager. In addition to this, the agent performs different tasks such as responding to information requests and sending notifications to the SNMP manager when any specific event occurs.
SNMP Manager
The system responsible for monitoring and managing the network devices is the SNMP manager. It communicates with SNMP agents to retrieve information and control the managed devices. The manager can issue requests to the agents to gather data, configure settings, or perform other management tasks.
Management Information Base (MIB)
The MIB is a structured database that defines the parameters and properties of the managed devices. It serves as a reference for the SNMP manager to understand what information is available from each device and how to interpret it. MIBs are organized hierarchically and use a tree-like structure.
SNMP Versions
There are several versions of SNMP, each offering different capabilities and security features:
SNMPv1: The original version of SNMP that provides basic monitoring and management functions but lacks security features.
SNMPv2c: An improved version of SNMPv1 with additional features such as improved error handling and support for 64-bit counters.
SNMPv3: The most secure version of SNMP that offers authentication, encryption, and access control features to protect management information transmitted over the network.
SNMP Operations
SNMP defines several operations for managing network devices:
Get: Retrieves the value of one or more managed objects from an SNMP agent.
GetNext: Retrieves the value of the next managed object in the MIB (Management Information Base) hierarchy.
Set: Modifies the value of a managed object on an SNMP agent.
Trap: Asynchronous notification sent by an SNMP agent to an SNMP manager to alert it of significant events or conditions.