Hi, Did you end up finding any solution to these issues?  Just in the last month we've suddenly had a lot of complaints about SMB share performance issues, I've tried everything I can think of at this point and still no change.   Thanks ... View more

You should be able to create an outbound firewall rule from the devices internal IP address to the public IP address you want to block, denying the traffic.  This wont stop the traffic coming in, but I think it might block the return traffic (you need to test this to verify).   Another method I haven't tried - but you could try creating a static route for the IP address you want to block and route it using the black hole method - to a local IP address on the LAN that does not exist.   RPF should caused packets that come in from the Internet to be blocked. ... View more