Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes.

Comprehensive Monitoring

  • Capabilities to monitor applications, services, operating systems, network protocols, system metrics and infrastructure components with a single tool
  • Powerful script APIs allow easy monitoring of in-house and custom applications, services, and systems

Visibility & Awareness

  • Centralized view of entire monitored IT infrastructure
  • Detailed status information available through web interface
  • Fast detection of infrastructure outages
  • Alerts can be delivered to technical staff via email or SMS
  • Escalation capabilities ensure alert notifications reach the right people

Problem Remediation

  • Alert acknowledgments provide communication on known issues and problem response
  • Event handlers allow automatic restart of failed applications and services

Proactive Planning

  • Trending and capacity planning addons ensure you’re aware of aging infrastructure
  • Scheduled downtime allows for alert suppression during infrastructure upgrades


  • Availability reports ensure SLAs are being met
  • Historical reports provide record of alerts, notifications, outages, and alert response
  • Third-party addons extend reporting capabilities

Multi-Tenant Capabilities

  • Multi-user access to web interface allows stake holders to view infrastructure status
  • User-specific views ensures clients see only their infrastructure components

Extendable Architecture

  • Integration with in-house and third-party applications is easy with multiple APIs
  • Hundreds of community-developed addons extend core Nagios functionality

Stable, Reliable, and Respected Platform

  • Over 10 years of active development
  • Scales to monitor thousands of nodes
  • Failover capabilities ensure non-stop monitoring of critical IT infrastructure components
  • Multiple awards, media coverage and recognition prove Nagios’ value

Vibrant Community

  • Over 1 million+ users worldwide
  • Active community mailing lists provide free support
  • Hundreds of community-developed addons extend Nagios’ core functionality

Customizable Code

  • Open Source Software
  • Full access to source code
  • Released under the GPL license

Lets   make  this  Tutorial including  two  Linux   Servers  .  The  nagios Server  and  Nagios  Client

My Systems :

Nagios  Server :   Centos 7
Nagios  Client  :   Centos 7


Nagios Requirements :

Your  need  some requirements before to install  Nagios    in  kind of  packagaes. please install the following packages before to initiate the Nagios  installations

Create  user and group Nagios

Create   nagios  user and set  password

useradd -m nagios
passwd nagios

Create Nagios group  nagcmd  and  add the user  and apache  user to the group
groupadd nagcmd
usermod -a -G nagcmd nagios
usermod -a -G nagcmd apache

Download  Last Nagios Core  and Plugins

From  Download last version

From ttp://     Download last version



Please apply the following  commands:

Explain the commands

make install
– This installs the main program, CGIs, and HTML files

make install-init
– This installs the init script in /etc/rc.d/init.d

make install-commandmode
– This installs and configures permissions on the
directory for holding the external command file

make install-config
– This installs *SAMPLE* config files in /usr/local/nagios/etc
You’ll have to modify these sample files before you can
use Nagios.  Read the HTML documentation for more info
on doing this.  Pay particular attention to the docs on
object configuration files, as they determine what/how
things get monitored!

make install-webconf
– This installs the Apache config file for the Nagios
web interface

make install-exfoliation
– This installs the Exfoliation theme for the Nagios
web interface

make install-classicui
– This installs the classic theme for the Nagios
web interface

For  nagios webinterface:

make install-webconf

This command  is important to create  nagios  httpd  conf   file ,   now we  need  to create   to  nagiosadmin user and password


Restart   Apahce   :

Install Nagios Plugins

Extract  and Compile

tar -zxvf nagios-plugins-2.1.3.tar.gz

cd  nagios-plugins-2.1.3


make  install

Now  the install  of  nagios Core +  plugins is  done

Nagios Server   Configuration

all   configuration files  should  be located  under /usr/local/nagios/etc

to change admin contact please  edit  : /usr/local/nagios/etc//objects/contacts.cfg  ( save  and  exit ) 


Configure Access to nagios  webfolder  

Please  edit  /etc/httpd/conf.d/nagios.conf



Please  configure it  following your  requirement    in  my   example , i didn’t change any thing

Security   (Selinux  and firewallcmd)


to avoid  issues  some  CGI acces  please  turn Selunux  to   permissive  option

vi /etc/selinux/config And, set SELinux to permissive mode.


Please add   http port  (80) to  allowed  zones  and reload  to   activate

Start   nagios Daemon


Access  webinterface Nagios Server

Please   Access  http://ip/nagios

and  login with  your login and password  defined before





I hope  you will  like this  Article.   in next  Article  i will explain how to  add  other  hosts  (Clients)   to this Server





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