Nagios - Powerful Network Monitoring Tool

Nagios is a powerful, enterprise-class host, service, application, and network monitoring program. Designed to be fast, flexible, and rock-solid stable. Nagios runs on *NIX hosts and can monitor Windows, Linux/Unix/BSD, Netware, and network devices.

With Nagios you can:

• Monitor your entire IT infrastructure
• Spot problems before they occur
• Know immediately when problems arise
• Share availability data with stakeholders
• Detect security breaches
• Plan and budget for IT upgrades
• Reduce downtime and business losses
• Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes.

Designed with scalability and flexibility in mind, Nagios gives you the peace of mind that comes from knowing your organization's business processes won't be affected by unknown outages.

Nagios is a powerful tool that provides you with instant awareness of your organization's mission-critical IT infrastructure. Nagios allows you to detect and repair problems and mitigate future issues before they affect end-users and customers.

What Nagios Provides -

By using Nagios, you can -

1. Plan for infrastructure upgrades before outdated systems cause failures
2. Respond to issues at the first sign of a problem
3. Automatically fix problems when they are detected
4. Coordinate technical team responses
5. Ensure your organization's SLAs are being met
6. Ensure IT infrastructure outages have a minimal effect on your organization's bottom line
7. Monitor your entire infrastructure and business processes

How It Works - 

Monitoring
IT staff configure Nagios to monitor critical IT infrastructure components, including system metrics, network protocols, applications, services, servers, and network infrastructure.

Alerting
Nagios sends alerts when critical infrastructure components fail and recover, providing administrators with notice of important events. Alerts can be delivered via email, SMS, or custom script.

Response
IT staff can acknowledge alerts and begin resolving outages and investigating security alerts immediately. Alerts can be escalated to different groups if alerts are not acknowledged in a timely manner.

Reporting
Reports provide a historical record of outages, events, notifications, and alert response for later review. Availability reports help ensure your SLAs are being met.

Maintenance
Scheduled downtime prevents alerts during scheduled maintenance and upgrade windows.

Planning
Trending and capacity planning graphs and reports allow you to identify necessary infrastructure upgrades before failures occur.visit nagious website -

http://www.nagios.org/ 

http://sourceforge.net/projects/nagios/ 

For Documentation -

http://www.nagios.org/documentation

Nagios Quickstart Installation Guides

For more information on nagious  & nagious plugins- 

http://en.wikipedia.org/wiki/Nagios

http://nagiosplugins.org/ 

Nagios Core 3.4.1 was released
Tuesday, 15 May 2012 15:42
Nagios Core 3.4.1 was just released and can be grabbed from the downloads page. The Changelog can be found here. This release fixed a bug that affected 3.4.0. Thanks to Andreas Ericsson and Eric Stanley for the quick bugfix and release.

Nagios Agents
Nagios Remote Plugin Executor
Nagios Remote Plugin Executor (NRPE) is a Nagios agent that allows remote systems monitoring using scripts that are hosted on the remote systems. It allows for monitoring resources such as disk usage, system load or number of users currently logged in. Nagios periodically polls the agent on the remote system using the check_nrpe plugin.

NSClient++
This program is mainly used to monitor Windows machines. Being installed on a remote system NSClient++ listens to port TCP 1248. Nagios plugin that is used to collect information from this addon is called check_nt. As NRPE, NSClient++ allows to monitor the so called "private services" (memory usage, CPU load, disk usage, running processes, etc.)

More Information about NSClient
http://www.nsclient.org/nscp/ 


Install & Configure nagious -
http://saylinux.net/story/003895/install-configure-nagios
http://www.thegeekstuff.com/2008/05/nagios-30-jumpstart-guide-for-red-hat-overview-installation-and-configuration/
http://assets.nagios.com/downloads/nagiosxi/docs/Installing_The_XI_Windows_Agent.pdf
http://searchdatacenter.techtarget.com/tip/Nagios-setup-Installing-and-configuring-the-network-monitoring-tool
http://www.nagios.org/download/core/thanks/
http://www.cyberciti.biz/tips/nagios-network-monitoring-server-monitoring.html
Nagios 3.0 Jumpstart guide for Linux - Overview, installation and configuration
How to monitor remote Linux host using Nagios 3.0
How to monitor remote Windows machine using Nagios on Linux

Screenshot -