Payload length

Hello everybody, i have experience with Icinga 1 - Classic. Now i would like install a new instance of Icinga2. The Icinga2-Server is installed on a Ubuntu 20.4 LTS- System. icinga2 use only the Webapplication “Icingaweb”. Now i would like to monitor Windowsserver with the NSClient++. I added the Windowsserver “Host” and Services successfully completed. The services use the NRPE plugin for monitoring.
The results of Memory, CPU and Disk are completed displayed, but with another output:
“CHECK_NRPE: Invalid packet version received from server.”

I found a solution. Maybe something is wrong with the paket lenght. A value must be set in the configuration file (NSclient). I have change the Value in: payload length=4096. After the change, the NSclient service was allready restarted. The result of the change is that the service now shows a timeout.

CHECK_NRPE STATE CRITICAL: Socket timeout after 10 seconds.

What did I forget to consider here? Thank you for the help. Please excuse my English

Hello Antono,
Welcome to the Icinga community. Thanks for joining us.

Are you able to connect to the remote system by using the command line to test?

/usr/lib64/nagios/plugins/check_nrpe -H 

Is the version of NRPE the same on both the client and the server?

BTW - the NRPE check command is insecure. You should consider using the the newer Icinga check commands that are included in the Icinga2 agent. I also upgraded from Icinga1. The new Icinga2 check command are much better than using the NRPE.


Hello Alex,

Thank you very much for your assistance. I will try to implement the proposal with the Icinga2-Agent.
In the case of any questions, i will post it here.

So i wish you a happy new here.