Here is a resource on installing Nagios Core on Rocky 9 that should help: https://docs.vultr.com/how-to-install-nagios-on-rocky-linux-9

this forum is meant for csp support, so you might be able to find better support here. If you aren't very knowledgeable with linux using CSP may be better choice for you. It does have a free version for non commercial use for up to 50 nodes if you are using it for a personal environment. CSP has a better GUI and makes it so you can perform all the tasks you need without going into the CLI for Linux.

I am having a really hard time trying to get a host to show up in the Nagios web console. I have installed Nagios core on rocky linux 9.5 without any issues. I installed NCPA on windows server 2022. I have attempted to follow the directions and I just don't seem to be getting it. I am not sure why my host is not showing up. I am not very knowledgable with linux so, you would have to talk to me in abc terms in order to get the information you need. EVERYTHING else has worked fine as far as installstion on rocky machine and windows server machine. I was al able to pull up the NCPA on the windows server 2022 and could see the dashboard etc. I don't think it's a connection issue I just think that there is some file not configured correctly.