Ports on Windows Server 2019 Not Listening?

[blake.phillips]

I am in the process of moving our Nagios Core monitoring to Azure. I have a new Linux VM in Azure, and I've copied the configs from on-prem into Azure. We are using NSClient++ to allow Nagios to talk to our Windows Machines. We are using an older version, so I figured it would be a good time to upgrade the NSClient, as I would be needing to go into each server to change the allowed hosts anyways.

So I chose a Windows Server 2019 machine, uninstalled the old version of NSClient, and installed the most recent version. However, any checks Nagios runs that goes over port 5666 and port 12489 are failing, while host checks and ping checks are working fine. The error I'm getting is the one where the Nagios server IP is not in allowed host on the client. However, the client is pointing to the new IP address. I've also checked the NSclient config and verified that check_nt is pointing to port 12489 and check_nrpe is pointing to port 5666.

I uninstalled the new version and installed the verison of NSclient that was previously on the machine (0.4.1.101), and I'm still running into the same issue (agent refused by host). If I run "Netstat -an" on the command line, I can see that the machine isn't listening on ports 12489 ad 5666. If I check any of the other machines, I see that ports 12489 and 5666 are listening. We have windows firewall disabled, so I know that isn't blocking anything, and we are allowing those ports on our network firewall. I imagine if I can get the ports to listen, that things would be working. The NSCP service is running, so I would imagine NSClient would take care of opening those ports. Did I uninstall the NSclient incorrectly?