SNMP can be used by Nagios in various ways. As the protocol is widely supported by operating systems and network devices, it is a great choice for monitoring a wide variety of machines. SNMP features a standardized way of describing typical parameters that describe a device—hardware, network connectivity, applications and services, and much more. This makes accessing this information from Nagios very easy. SNMP is enabled by default on many operating systems and on most network devices, which makes it very easy to monitor such devices in Nagios.

In this chapter we learned what SNMP is and saw the different versions of the protocol—SNMPv1, SNMPv2c, and SNMPv3. We also learned what OIDs are and how they are used to access data over SNMP. This chapter also covered how to access SNMP data graphically using various tools. This can be of great help when starting with SNMP in order to better understand it.

We learned how to use SNMP from Nagios—both for querying various SNMP-enabled devices...