Book Image

Nagios Core Administration Cookbook

By : Tom Ryder
Book Image

Nagios Core Administration Cookbook

By: Tom Ryder

Overview of this book

Network monitoring requires significantly more than just pinging hosts. This cookbook will help you to comprehensively test your networks' major functions on a regular basis."Nagios Core Administration Cookbook" will show you how to use Nagios Core as a monitoring framework that understands the layers and subtleties of the network for intelligent monitoring and notification behaviour. Nagios Core Administration Guide introduces the reader to methods of extending Nagios Core into a network monitoring solution. The book begins by covering the basic structure of hosts, services, and contacts and then goes on to discuss advanced usage of checks and notifications, and configuring intelligent behaviour with network paths and dependencies. The cookbook emphasizes using Nagios Core as an extensible monitoring framework. By the end of the book, you will learn that Nagios Core is capable of doing much more than pinging a host or to check if websites respond.
Table of Contents (18 chapters)
Nagios Core Administration Cookbook
About the Author
About the Reviewers

Checking an alternative SSH port

In this recipe, we'll learn how to deal with the common situation of a machine running an SSH daemon that is listening on an alternative port. So, a service definition that uses check_ssh, as used in the Monitoring SSH for any host recipe, fails because the plugin defaults to using the standard SSH TCP port number of 22.

This kind of setup is common in situations where an SSH server should not be open to the general public and is often employed as a "security by obscurity" method to reduce automated attacks against the server. The SSH daemon is therefore configured to listen on a different port, usually with a much higher number; administrators who need to use it are told what the port number is.

We'll deal with this situation and monitor the service in Nagios Core, even though it's running on a non-standard port. We'll do this by defining a new command that checks SSH on a specified port number, and creating a service definition that uses that command. The...