From our experience it is best to have the smallest classes of scans, so rather than scan /14 or /8 which could be a lot of hosts, scan at most /24 (class C) and have several of them run at the same time.

This gives the following advantages:

1. Finishes quickly, if you scan /8 it can take hours, or even days to complete - while having several /24 will allow you to see the results more quickly - there is no benefit in scanning more hosts, the results are the same if you scan 2, 4 or 10 hosts.

2. You can run several such smaller scans at the same time window and use this to maximize your scanner's capability - the scanner by default scans up to 8 hosts in parallel - combining several scans can give you more per second tested host than one scan.

3. The results are easy to combine even when the scans didn’t occur at the same time.

4. Smaller scan time window can be more accurately controlled, most scans of /24 take about 1 hour to complete, while /8 scans' scan length varies a lot more.