How To Install NRPE on Ubuntu 20.04 LTS

Install NRPE on Ubuntu 20.04

In this tutorial, we will show you how to install NRPE on Ubuntu 20.04 LTS. For those of you who didn’t know, NRPE is a client-side application for executing Nagios plugins. The Nagios server communicates with the remote system using this plugin. NRPE must be installed on all the remote systems that need to be monitored by the Nagios server. It allows the gathering of metrics such as system load, disk utilization, uptime, etc.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of the Nagios Client (NRPE) on Ubuntu 20.04 (Focal Fossa). You can follow the same instructions for Ubuntu 18.04, 16.04, and any other Debian-based distribution like Linux Mint.


  • A server running one of the following operating systems: Ubuntu 20.04, 18.04, and any other Debian-based distribution like Linux Mint or elementary OS.
  • It’s recommended that you use a fresh OS install to prevent any potential issues.
  • An active internet connection.
  • A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install NRPE on Ubuntu 20.04 LTS Focal Fossa

Step 1. First, make sure that all your system packages are up-to-date by running the following apt commands in the terminal.

sudo apt update
sudo apt upgrade

Step 2. Installing NRPE (Nagios Remote Plugin Executor) on Ubuntu 20.04.

NRPE packages are available under the default repositories on Ubuntu systems. Now run the following command to install it:

sudo apt install nagios-nrpe-server nagios-plugins

Once installed, verify the status of the NRPE agent using the following command:

sudo systemctl status nagios-nrpe-server

For additional resources on installing Nagios, read the post below:

Step 3. Configure NRPE.

Now we edit the NRPE configuration file /etc/nagios/nrpe.cfg and make the necessary changes like below:

sudo nano /etc/nagios/nrpe.cfg

Add your Monitor server address to the allowed_hosts parameter as a comma-separated list in the appropriate section:


Save the changes and exit the configuration file. For the changes to take effect, be sure to restart the NRPE agent daemon:

sudo systemctl restart nagios-nrpe-server

You can verify the connection from the Nagios server to remote use check_nrpe the script, which is available on the Nagios core server:

check_nrpe -H

Step 4. Configure Firewall Rules.

The default NRPE service listens on port 5666. Use the following commands to open the firewall port for NRPE service:

sudo firewall-cmd --permanent --zone=public --add-port=5666/tcp 
sudo firewall-cmd --reload

Congratulations! You have successfully installed NRPE. Thanks for using this tutorial for installing the Nagios Client (NRPE) on the Ubuntu 20.04 LTS Focal Fossa system. For additional help or useful information, we recommend you check the official Nagios website.

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r00t is a seasoned Linux system administrator with a wealth of experience in the field. Known for his contributions to, r00t has authored numerous tutorials and guides, helping users navigate the complexities of Linux systems. His expertise spans across various Linux distributions, including Ubuntu, CentOS, and Debian. r00t's work is characterized by his ability to simplify complex concepts, making Linux more accessible to users of all skill levels. His dedication to the Linux community and his commitment to sharing knowledge makes him a respected figure in the field.
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