NRPE Invalid packet version received from server

[tonnag]

Hi, I got nagios running on a debian machine which goes real well
root@monitor:# /usr/local/nagios/bin/nagios -v
Nagios Core 4.4.3
Copyright (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 2019-01-15
License: GPL

Now I want to add extra checks on my servers, and installed nrpe which works
root@monitor:# /usr/local/nagios/libexec/check_nrpe -V
NRPE Plugin for Nagios
Version: 3.2.1

And since i wanna use custom checks, I went for the check_mk agent which also works
root@monitor:# telnet logserver.lan 6556
Trying ::1...
Connected to localhost.
Escape character is '^]'.
<<<check_mk>>>
Version: 1.5.0
AgentOS: linux
Hostname: monitor
AgentDirectory: /etc/check_mk
.......
.......

but the two together ..... won't
root@monitor:# /usr/local/nagios/libexec/check_nrpe -2 -n -H logserver.lan -p 6556
CHECK_NRPE: Invalid packet version received from server.

Any suggestions ?
Thnx Ton

[npolovenko]

Hello, @tonnag. Check_nrpe requires a remote NRPE agent. The remote nrpe agent is installed on the monitored server and it's supposed to execute given commands on the monitored server and send the result back to Nagios.
https://assets.nagios.com/downloads/nag ... e/NRPE.pdf
I'm not familiar with check_mk but looks like its a monitoring tool? Is there a specific set of commands that you can run against the check_mk plugin to get the desired information about the monitored system? Can you demonstrate such commands and show me the output?

[tonnag]

npolovenko, thnx for responding, but it's my mistake.
I wanna use the check_mk agent on the remote systems and thought it would work as a 1:1 replacement of the nrpe agent.
So besides the check_mk agent I installed an nrpe agent to compare output. That's not alike so i'm off-track for that one.

the NRPE works just fine with it's own agent

[npolovenko]

@tonnag, Perhaps check by ssh would work for you? It can execute commands on the remote server without an agent.
You'd need to exchange ssh keys on servers. Here's the tutorial:
https://assets.nagios.com/downloads/nag ... ng_SSH.pdf

[tonnag]

great idea! thnx, it might indeed work better/faster in this case

[npolovenko]

@tonnag, Awesome. Do you have any additional questions for us before I lock this thread?

[tonnag]

nope. THNX!

[scottwilkerson]

nope. THNX!

Great!

Locking thread