Nagios Support Forum

I am not able to see the remote hosts after installation and configuration of nagios nrpe. Attached is the document followed to install nrpe.

Please advise.

Thank you,
Sachin A

Have you also created host and service configs on the Nagios server for each of the machines you wish to monitor via NRPE? This will need to be done as NRPE is an active agent, meaning Nagios needs to perform the checks instead of NRPE sending results back to Nagios on its own.

I see that that there are 2 nagios.cfg file and one hosts.cfg file on the server. Which one I need to configure.

./etc/nagios/nagios.cfg
./usr/local/nagios/etc/nagios.cfg


./etc/nagios/objects/CTR/hosts.cfg

Please advise.

Thank you,
Sachin A

With Core it's difficult to know for sure. What version of Core are you using? Was it compiled from source or installed from distro repos? On what OS/version is nagios running? cat /etc/*-release may be of use.

If you mix and match repos and source, you will run into trouble.

That said, it's probably /usr/local/nagios/etc/nagios.cfg

I am installing nagios-4.2.4.
A. Download Nagios Core and Plugins
B. Required Nagios pre-installation packages/rpms
C. create nagios OS user and nagcmd group
D. Untar the software to the server under /root/repos directory
E. ./configure --with-command-group=nagcmd

That looks like a paraphrase of your steps, but in case that is step-by-step, you are missing some make steps listed at https://support.nagios.com/kb/article.php?id=96

That ./etc/nagios/nagios.cfg still looks worrisome to me.

What's the output of rpm -qa nagios*? You didn't give us the output of cat /etc/*-release, so not sure if you are running a rpm-based distro, so you may need to modify that for your package manager.

Is it mandatory to install NRPE on Nagios Core server as well? What is the compatible NRPE version with Nagios Core?

Please advise.

Thank you,
Sachin A

sachinambardekar wrote:Is it mandatory to install NRPE on Nagios Core server as well? What is the compatible NRPE version with Nagios Core?

Please advise.

Thank you,
Sachin A

You need to compile the NRPE plugin in order to check via NRPE through the systems. Core will work with NRPE v2.15 or v3 - see the articles here - https://support.nagios.com/kb/category.php?id=22

Sorry, not following what you mentioned in your previous post. Do I have to install NRPE along with Nagios core on the server where Nagios Core is installed in order to monitor Nagios Core server?

Please advise.

Thank you,
Sachin A

sachinambardekar wrote:. Do I have to install NRPE along with Nagios core on the server where Nagios Core is installed in order to monitor Nagios Core server?

Maybe it would be helpful if we took a step back to see what you are actually trying to do. Your subject talks about remote hosts. Now you're talking about monitoring the Nagios Core server itself. Could you describe a bit more about what you are trying to do? Maybe NRPE is not the best method for what you are trying to do.

Could you please post your nagios.cfg?
Also, could you post any /usr/local/nagios/etc/nrpe.cfg you have set up and tell us where you have them set up.