Open source Nagios is an enterprise-class tool, used for monitoring networks, which runs on Linux and Unix. By running periodic checks on user-specified resources and services, Nagios ensures faster fixes for network issues.
Chapter 7 -- "Testing Local Resources" -- of Nagios: System and Network Monitoring details the various plug-ins needed to work with Nagios and how to test them over a local network since some lack their own network protocol.
Excerpted from Nagios: System and Network Monitoring, First edition by Wolfgang Barth (ISBN: 1-59327-070-4). Copyright © April 2006 No Starch Press, Inc. All rights reserved.