How to limit ARD/VNC tries to connect to host?

Hello

I want to limit the tries to connect to an host with Apple Remote Desktop or VNC to only 5 or 10 times and then block the IP for e.g. 48 hours.

Is their an CLI Command to protect my host from internal/external attacks

In the Control Panel we have not active the the VNC Access with only a password, but we also want do block attacks with VNC or ARD Clients over 5900 without Username/Password.

27.05.15 15:42:37.712 screensharingd[76794]: Authentication: FAILED :: User Name: N/A :: Viewer Address: 89.248.xxx.xxx :: Type: VNC DES

27.05.15 15:42:38.124 screensharingd[76794]: Authentication: FAILED :: User Name: N/A :: Viewer Address: 89.248.xxx.xxx :: Type: VNC DES

Wo is able to help me