Nagios NRPE Error: service/protocol combination not in /etc/services: nrpe/tcp
It had been awhile since I have installed NRPE or Nagios Remote Plugin Executor running through xinetd so once I thought I had everything configured I attempted to restart xinetd but NRPE was not working properly. Below I describe the error in more detail along with how I resolved the issue. In the below example the server was running CentOS Linux.