Summary
Nagios can leverage multiple solutions to monitor resources on remote machines—such as disk usage, swap, or other metrics.
In this chapter, we have learned the following items:
Using SSH for running checks on remote machines
Running multiple checks at once over SSH
Troubleshooting the SSH-based checks
Using NRPE for performing remote checks
Setting up NRPE server and client as well as NRPE-based checks in Nagios
Troubleshooting SSH and NRPE connections
How SSH and NRPE differ from each other and when to use each of them
The next chapter talks about Simple Network Management Protocol (SNMP), which is a protocol for monitoring and managing various types of devices connected to a network. The protocol supports both querying the device as well as receiving information from the devices regarding the failure. The SNMP protocol is used by a large variety of devices, from network switches and routers to mainframe servers.