I have configured a Nagios Core 4.4.14 in a Rocky Linux 8.10 host. All configuration seems to be running perfectly but, now, I need to check some hosts that are behind a NAT/firewall host (this host is already monitored and checked from my server). That hosts have, also, some services (disk, load, check some NFS folders) that should be checked. If a use NRPE, I suppose I need to open some port s in the NAT/firewall to check all servers (one port to each host), so my question is if there is a better configuration to check that servers and their services.

Thanks.

  AuthDigestDomain "Nagios"

  AuthDigestProvider file

  AuthUserFile "/etc/apache2/.htpasswd.users"

  AuthGroupFile "/etc/groups"

  AuthName "Nagios Login"

  AuthType Digest

  Require valid-user

I do not get the login prompt when accessing localhost/nagios4. Am I missing something? I even tried to surround the above-mentioned code with <RequireAll></RequireAll> and to no avail.

define contact {
host_notifications_enabled 1
service_notifications_enabled 1
contact_name root
service_notification_period 24x7
host_notification_period 24x7
service_notification_options w,u,c,r
host_notification_options d,r
service_notification_commands notify-service-by-email
host_notification_commands notify-host-by-email
email root@localhost
}

define contactgroup {
contactgroup_name admins
alias Nagios Administrators
members root
}

I get an error when I include the following in contacts.cfg (If I remove this, the error goes away):

define contactgroup {
contactgroup_name admins
alias Nagios Administrators
members root
}

The error I receive is the following: 

Warning: Duplicate definition found for contactgroup 'admins' (config file '/etc/nagios4/objects/contacts.cfg', starting on line 46)
Error: Could not add object property in file '/etc/nagios4/objects/contacts.cfg' on line 48.
Error: Service notification period '24x7' specified for contact 'root' is not defined anywhere!
Error: Could not register contact (config file '/etc/nagios4/conf.d/contacts.cfg', starting on line 1)
Error processing object config files!

I have no reason to think the new people shouldn't, but I'd rather not wait till some error actually happens, that they might miss, to find out.

I have core 4.5.0, Yep older, but it's also on rhel 7.9, which is currently on extended support. A new nagios server is in the works.

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.