Useful information on ports required for WMI remote monitoring can be found in the Connecting Through Windows Firewall article on the Microsoft website.
In addition, any Uptime Infrastructure Monitor monitors that connect directly to applications on the target server must have ports specific to those applications open. For example, port 1433 is required for a basic connectivity check to a SQL Server installation.
Other Port related articles:
Required Ports for the Uptime Infrastructure Monitor Monitoring Station
What ports need to be open to add an ESX or vCenter system to Uptime Infrastructure Monitor?
Add firewall rule to open port 9998 for Linux agent
Changing the Windows Agent Port
Configuring SQL Server Ports