How to configure Windows NRDS client to work with NagiosCore

[hart09]

Hi there,

I have installed Nagios Core and also NRDP service. I can get to 192.168.1.1/nrdp.

I also installed NRDS_Win_64.exe on Windows machines, to monitor remote windows machines (behind firewall, http and https is allowed).

But when going to the server 192.168.1.1/nagios to see if my remote clients are there, I see nothing. Is there any tutorial on how to configure Windows client? And where exactly in 192.168.1.1/nagios I should find my remote clients?

[Box293]

This KB article, while it is specific for Nagios XI, should have most of the information you are after:

https://support.nagios.com/kb/article.p ... tegory=126

[nozlaf]

I dont use NRDS i use NSClient++ but i believe the same applies

for core you need to add each host to the core config before they show up ( certainly this is true)

XI has a feature to show unknown hosts and quickly add them to nagios xi however core doesnt have this functionality

the entry has to match what the server / client being monitored is called which can sometimes be the fully qualified domain name of the machine in question

and the hosts need to have services which match what you are running in your NRDS config (I believe this to be true)

and I believe you need to use dummy checks to keep core happy but I could be wrong

for example
Host Definition

Code: Select all

[host]
define host {
                host_name                            DUMMYHOSTNAME
                alias                                  DUMMYHOSTNAME
                address                               8.8.8.8
                check_command                         check_dummy!
                notification_interval                 15
                notification_options                  d,u,r
                max_check_attempts                    3
                active_checks_enabled                 1
                passive_checks_enabled                1
                notifications_enabled                 1
                check_period                          24x7
                notification_period                   24x7
                contact_groups                        24x7_SMS_and_Helpdesk,admins
}

Service Definition

Code: Select all

define service {
                service_description                   Passive_CPU
                check_command                         check_dummy!
                host_name                             DUMMYHOSTNAME
                check_period                          24x7
                notification_period                   24x7
                contact_groups                        24x7_SMS_and_Helpdesk,admins
                event_handler_enabled                 0
                notification_interval                 15
                notification_options                  w,u,c,r
                passive_checks_enabled                1
                notifications_enabled                 1
}

[rkennedy]

Thanks @nozlaf!

@hart09 - let us know if you have any further questions after reading the above responses.

[hart09]

I ended up configuring Nagios XI. Now I have a Nagios XI server that is in the DMZ behind the firewall. Its IP address 192.168.9.xxx is NATed to a public IP. I have external Windows NRDS clients that send data to the Public IP of Nagios.

But Nagios XI only accepts requests on its private DMZ IP. Do you know how to chagne Nagios Xi config so it accepts http requests on its public IP too?

[rkennedy]

Are you using a 1:1 NAT translation? This sounds like a firewall, or NAT forwarding issue.

[hart09]

The IP address 192.168.9.xxx is NATed to a public IP 84.56.xxx.xxx. I can get from remote Windows computer using a browser to 84.56.xxx.xxx/nrdp using a web browser. But the remote Windows client hosts do not get prepopulated in Nagios interface in unresolved host section.

Only local test clients from the 192.168.9.xxx get in there.

By looking at the Inbound Transfers section in Nagios Xi Admin page it says the following:

The NRDP API can be accessed at http://192.168.9.xxx/nrdp/

So, to me it means it listens only on 192.168.9.xxx IP address and not on the public one 84.56.xxx.xxx.

Please let me know how can I make this work.

Thanks!

[nozlaf]

So, to me it means it listens only on 192.168.9.xxx IP address and not on the public one 84.56.xxx.xxx.

that is the nature of NAT, the XI server is 192.168.9.x not 84.56.x.x

you say you can access 84.56.xxx.xxx/nrdp using a web browser from a machine external to the 192.168.9.x range that would indicate you have setup the server side correctly

from the clients which are external to your network can you ensure that you have setup the client correctly and the url has the 84.56.x.x/nrdp address in there (should use identical configuration to the internal clients just different URL (external not internal IP) and token (assuming you use different token for each client)

[rkennedy]

Thanks @nozlaf! You're spot on, it sounds like outgoing NAT'ing is going on, but no port forwarding for is setup for incoming requests.

Let us know if you have any further questions.

[hart09]

Yes, the client is correctly configured with 84.56.x.x/nrdp address. Checked all of that.

What I think it is, Nagios XI is listening only on 192.168.9.xxx.xxx IP. I just can't find where I can edit this? So it only accepts headers addressed to 192.168.9.xxx.xxx IP. From the screenshot attached you can see that it accepts NRDP API only on 192.168.9.xxx

I have erased the token from the screenshot on purpose, but it is there too.