Although it is generally accepted that scanning computers over the Internet is not a crime, it's also not appreciated by system administrators. There are thousands of scans every second, across all areas of the Internet—but that doesn't mean that you won't get an abuse complaint (or worse) if you scan the wrong machine. Make sure that any target you choose is aware of (and consents to) whatever scan you may decide to conduct. There are a few ways that you can make your own targets—which some readers might find easier than using free ones online.

The most simple target, and easiest to set up, is to just use another computer on your local area network. You can use your router (usually located at 192.168.1.1 for home routers), another machine on your network (which we'll talk about finding), or even buy a cheap laptop to use as a test lab.

If you do not have access to another machine to scan or do not feel comfortable (or authorized) to scan another machine, you can create...