SNMP stands for Simple Network Management Protocol. It is an Internet Standard protocol that is used for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. SNMP is an application layer protocol included in the internet protocol suite. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more. SNMP is used to collect data related to network changes or to determine the status of network-connected devices. Collecting this data can help IT professionals keep their finger on the pulse of all their managed devices and applications. Every device within the network can be queried in real-time with SNMP, TCP, and other types of probes for their performance metrics. When thresholds for certain values are exceeded, software can alert system administrators of the issue, allowing them to drill into the data and troubleshoot a solution.
SNMP exposes management data in the form of variables on the managed systems organized in a management information base (MIB), which describes the system status and configuration. These variables can then be remotely queried (and, in some circumstances, manipulated) by managing applications. The SNMP architecture is simple, and the data hierarchy the protocol uses can seem complicated if you’re not familiar with it. Fortunately, it’s relatively simple once you understand the philosophy behind it. To provide flexibility and extensibility, SNMP doesn’t require network devices to exchange data in a rigid format of fixed size. Instead, it uses a tree-like format, under which data is always available for managers to collect.
SNMP has different versions, and the first version of SNMP—SNMPv1—offers weak security features. Under SNMPv1, managers can authenticate to agents without encryption when requesting information. That means anyone with access to the network could run “sniffing” software to intercept information about the network. It also means an unauthorized device can easily pretend to be a legitimate one. SNMPv3 defines the secure version of the SN...
