We currently have a windows firewall rule in place to ALLOW RDP connections only on specific ports (non-defualt). This does not contain a whitelist of IP addresses and currently allows all IP's to connect.
In an attempt to reduce the number of overseas attacks (I know a hardware solution would be more robust but have not received approval for this), I would like to put a secondary "block" rule in to blacklist IP ranges from suspicious countries.
How do rules interact with each other? If one rule is allowing connections without an IP list, would that override the "block" rule? Or will the "block" rule override (i.e. if I leave local IP addresses set to Any IP Address will this automatically block all local IPs?
Basically I'm looking to keep all local IPs accessible and only manage a blacklist rather than a whitelist.
What's the best way to achieve this while still only allowing the specific custom port I have setup?