Hi Umath,
This is no abacadrabra it is just how easy it is to make part of a script to filter IP packets. Has nothing to do with Kerio, it is just additional, and you can have these when you run an open software firewall for Windows as well. What am I talking about. Well we would like to see that all packets with source or destination: 127.0.0.1, 0.0.0.0, 10.*.*.*.* (the address of your machine or moden (10.0.0.13*), or 172.16.31.*.* or 192.168.*.* (as they are for internal use only) to be dropped, with internal source address from passing inward, the similar from external passing outward, and destination addresses likewise (external dropped inward, and internal destination dropped outward), furthermore drop all source routed packets.
This are the general rule for filtering IP trafick, if you are attacked, and you wanted the hostile packets dropped from the evil site, you could use the script I gave you here. It is just to demonstrate how easy you can configure your IP firewall in open source or make special filters for it.
Linux people do this all of the time, but it is coming in on Windows implementations as well. So the two things had not much in common. If it was off off topic. one could move this posting out. It was just put there to get you all to think actively about filtering, also in a FW. I have built a pre-router filterscript into ZA, and it works super.
polonus