The following steps will install the NRPE Client / Agent version 2.15. This uses a custom installer from Nagios Enterprises, it automates the installation and configuration process and it much easier than installing from source.

These steps were performed on a CentOS 6.5 server (minimal install).

Install NRPE Client / Agent

• Type yum -y install wget openssl-devel and press Enter
• Type cd /tmp and press Enter
• Type wget http://assets.nagios.com/downloads/nagiosxi/agents/linux-nrpe-agent.tar.gz and press Enter
• Wait for the file to download 
• Type tar xzf linux-nrpe-agent.tar.gz and press Enter
• Type cd linux-nrpe-agent and press Enter
• Type ./fullinstall and press Enter
• Type y and press Enter
• Wait for the fullinstall command to complete
• When prompted, type the IP Address of your Nagios Core host, for example:
  
• Type 192.168.142.129 and press Enter

The NPRE Client / agent is now installed and listening on port 5666.

Instructions for installing the NRPE Agent are located here.

https://support.nagios.com/kb/article.php?id=515

Test NRPE Client / Agent

This will test that the NRPE Client / Agent is properly installed and listening on port 5666. The following command is executed on a Nagios Core server and the computer running the NPRE Client / Agent has the ip address 192.168.142.132.

• Type /usr/local/nagios/libexec/check_nrpe -H 192.168.142.132 and press Enter
• You should receive a response like:
  
• NRPE v2.15
• This confirms the NRPE Client / Agent is working