During host checks, CloudRadar obtains information about hosts by making direct calls from some of its data centers to the hosts. In case the hosts you need to monitor are in your intranet and cannot be accessed from Internet, CloudRadar would not be able to perform the host checks directly.
The solution in this case is to install a tiny application (referred to as frontman) on one of your servers within that intranet. The frontman serves as a data collector, and works as follows:
In CloudRadar, you configure some hosts to use a certain frontman, and define checks for these hosts.
CloudRadar sends information to this frontman about the checks.
The frontman connects to the hosts in your intranet, performs regularly the checks, and sends the results to CloudRadar.
In CloudRadar, you check the monitoring data for your hosts as usual on the Latest data page.