The objective is to submit the solution for those situations where the netstat command return empty.
When checking if the agent is running, the return of the netstat command is empty.
[root@localhost nrpe-2.13]# netstat -vantup | grep 5666 [root@localhost nrpe-2.13]#
The NRPE is not running or is running on a different port.
For systems running Solaris, look for error in the log, as shown in the example below:
[root@localhost]# tail -f /var/adm/messages
For systems running Linux, look for error in the log, as shown in example below:
[root@localhost]# tail -f /var/log/messages
Or check the process agent installation again, paying attention the each step.