Essential SNMP, 2nd Edition

Nagios

Nagios is a comprehensive monitoring software package that, if installed and configured properly, can work nicely for many small to large companies. It has all the typical features like status overview, map view, and an alerts screen (just to name a few), but it goes a step further to give you sections on trends, a tactical overview, and process and performance data. Beyond that, Nagios offers some rather advanced features such as 3D maps of your network (using Virtual Reality Markup Language or VRML) and a WAP interface for cell phones.

Nagios is pretty easy to download and compile. The online docs are useful and easy to read. Experienced users recommended that I download and install the Nagios plug-ins as well. These plug-ins are little pieces of software (which must also be compiled) that do most of the actual monitoring checks (check_pop, check_ssh, etc.). In my setup, I used the check_ssh program to ensure that the SSH port (22) was open and available. Before installing Nagios, you must have the Apache web server installed and configured.

While many packages give you the ability to monitor and show typical alerts, Nagios has the ability to monitor servers and services and group them efficiently to generate a variety of related notifications.

After installation, configuring the product took some time. I had to trudge through numerous configuration files (with the help of the documentation) to get everything up and running. Even with the example files, it took a few hours ...