Sure, you can! This is the part where IP filtering by country and subnet can keep your ports hidden. Also stateful firewall can be crafted to only let certain

Sure, you can! This is the part where IP filtering by country and subnet can keep your ports hidden. Also stateful firewall can be crafted to only let certain IP thru after sending a specially-crafted TOTP into a ICMP packet just to get into opening the firewall for your IP.