True ISP's frown upon portscanning. I myself have had one of the Admin's of the ISP at work call me and ask what I was doing. Nothing I say, just a lil port scanning. They get emails from Admin's that say that they are getting scanned from a certain IP. I personally get scanned hundreds of times within a week on my firewalls. It's part of life on the net. The best practice is to keep your packages/images/firmware/etc... up to date and log everything.......