I installed Op5 (Nagios) monitoring server on CentOs 6.8 in Hyper-V environment on our Local server with public IP and I could monitor smoothly all the servers on Hyper-V locally and the servers on Azure cloud except one server on Azure which is windows server 2012 R with a domain controller , I have opened the require ports on Azure portal and locally on the DC virtual machine's firewall and I used the same configuration with the other servers on Azure and all are working well accept the domain controller ?
I got "CHECK_NRPE: Socket timeout after 10 seconds. for all the services"
I test the working servers on Azure for port 5666 and it is all working well and I tried to test the DC with port 5666 from outside the network but it can not be reached even I opened the ports in the same way I opened it to the other servers on Azure? the ports are opened on the two-tier , on Azure firewall and on the DC machine firewall.
on Op5 configuration file already set up the allowed hosts to IP of the Op5 monitor server.
any hints ?