So you will most likely set up Nagios on a Linux server. Well most people do anyway. But most networks also have Windows servers that need monitoring. It is very easy to connect Windows servers to the Linux Nagios monitoring server. In this video I take you through the whole process for connecting a Windows server. This is one lesson in a complete course I offer on Udemy. The course covers setting up the Nagios server on both Red Hat and Ubuntu based Linux systems, and how to connect Linux and Windows servers to be monitored. 

https://www.udemy.com/setting-up-nagios-4/?couponCode=ASG-BLOG

The coupon is good until December 31st 2017 and gets the course for you for $10. 

When you are setting up Nagios to monitor remote servers you need to create a new cfg file for each remote server. If you are monitoring a remote Linux server there are a listing of 7 services that are very typically set up to monitor by default. These are the same as what is the default set for the localhost list on your Nagios monitoring server. Here is a sample of what you would put into a file for a Linux server. In this case my server is named Kittyhawk and I would call the configuration file kittyhawk.cfg. Typically you would put this file in /etc/nagios/servers or you might find you need to put it in /usr/local/nagios/etc/servers.

define host {
       use             linux-server
       host_name         kittyhawk
       alias             My second server
       hostgroups         linux-servers
       address             xxx.xxx.xxx.xxx
       max_check_attempts     5
       check_period         24x7
       notification_interval     30
       notification_period     24x7
}

define service {
       use             generic-service
       host_name                       kittyhawk
       service_description     SSH
       check_command     check_ssh
       notifications_enabled     0
}

define service{
   use                 generic-service
   host_name             kittyhawk
   service_description     CPU Load
   check_command         check_nrpe!check_load
}

define service{
   use                 generic-service
   host_name             kittyhawk
   service_description     Current Users
   check_command         check_nrpe!check_users
}

define service{
   use                 generic-service
   host_name             kittyhawk
   service_description     Boot disk space
   check_command         check_nrpe!check_boot_disk
}


define service{
   use                 generic-service
   host_name             kittyhawk
   service_description     Root disk space
   check_command         check_nrpe!check_root_disk
}

define service{
   use                 generic-service
   host_name             kittyhawk
   service_description     Total Processes
   check_command         check_nrpe!check_total_procs
}

define service{
   use                 generic-service
   host_name             kittyhawk
   service_description     Zombie Processes
   check_command         check_nrpe!check_zombie_procs
}


​

You can add more services to monitor for the remote server depending on what it does and what you need to monitor. This one also assumes you are using nrpe to connect to the remote server. 

If you want to try out Linux then the first step is to download an ISO image. Then you can either attach a virtual machine to that ISO image to install, or you can create a bootable USB stick to boot a physical computer with to install. Of course you can also burn a bootable CD. Creating a CD is easy and common knowledge. In this video I show you how to find a distro, locate a place to download the ISO image, then make the bootable USB stick from it using a great utility on Windows. The process is actually quite easy once you see it.