Enable the Nagios NRPE Server

by Mike on January 12, 2009 · 2 comments

in Nagios

One you have the remote host set up you will need to set up the Nagios monitoring server. This tutorial will show you how to set up the Ubuntu 8.10 server so that it can monitor the remote Linux host. First install the nrpe plugin.

# apt-get install nagios-nrpe-plugin

Enable a Command Definition
The command to enable the nrpe has already been set by default so you will not have to do anything.

Create the Host Files
In order to monitor remote Linux boxes you will need to set up your template called “linux-box” and then you will need to create a host entry for each remote box you will monitor.

define host{
name                    linux-box
use                     generic-host
check_period            24×7
check_interval          5
retry_interval          1
max_check_attempts      10
check_command           check-host-alive
notification_period     24×7
notification_interval   30
contact_groups          admins
register                0
define host{
use                     linux-box
host_name               dg
alias                   Base

Configure Services
Each service you want to monitor on the remote host must be entered individually.  Here is an example of monitoring CPU load on the host “dg”.

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

Once this is complete you must restart your nagios server with:

sudo /etc/init.d/nagios3 restart

and the web server so you can see the results.

/etc/init.d/apache2 restart
If you get errors correct them.

Now you can check your connection by running the following command and using the IP Address of the remote box you want to monitor.  You should get the return “NRPE v2.8.1” if all is working.

# /usr/lib/nagios/plugins/check_nrpe -H
NRPE v2.12

If you get this return then you have communication between the Nagios monitoring server and the remote host.

Now run a command from the command line.  Here you will be checking the load on the remote host and you should get the information you are looking for.

# /usr/local/nagios/libexec/check_nrpe -H -c check_load
OK – load average: 0.09, 0.07, 0.07|load1=0.090;15.000;30.000;0; load5=0.070;10.000;25.000;0; load15=0.070;5.000;20.000;0;


Dani December 17, 2009 at 9:08 pm

I have installed a nagio-nrpe-plugin on Nagios server machine for monitoring services on remote host(communicate with nrpe server).
The remote host(ubuntu) is installed on virtual box and consist nagios-nrpe-server.

but there is problem when i was run a command on Nagiso Server machine

/usr/lib/nagios/plugins/check_nrpe -H

then it responses that the
“Connection refused by host”

any one know about that? thanks


mike December 19, 2009 at 9:49 am

Check your firewall settings ….and remember also be sure the client is listening on port 5666. On the client run this command:

netstat -aunt

You should see listed port 5666, if not your client is not set up right.

Previous post:

Next post: