i have a ubuntu host system with virtualbox running a windows server. In Virtualbox i have configured the network with a NAT interface and port forwarding for the RDP deamon running inside the vm.
That works really well - i can connect to the windows rdp service over the internet. TCP *:3389 -> *:3389
Now i like to restrict the access to the rdp service to only 3 public ip addresses and have no idea how to do that via iptables / shorewall.
ACCEPT net:91.x.x.x fw tcp 3389
(shorewall rule) isn't working.
Would be glad for any hint.