Dealing with stuck hosts
Unfortunately, when dealing with large blocks of IP addresses—which is a very common occurrence if you're scanning a large enterprise, whether for internal security purposes or as a client engagement—it isn't uncommon to deal with stuck hosts.
When a host gets stuck, it means that something is stopping the scan from completing at a normal rate. This could be caused by something benign such as a network hiccup on either end of the connection, or something more intentional such as a security software that is intentionally making the target host respond very slowly or inconsistently—effectively breaking the scan.
For the purposes of demonstration, I am going to start a ping agnostic (-Pn) scan against a host that doesn't exist ...
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