Adjusting scan groups
Nmap uses scan groups when processing multiple targets in parallel. This is important as new scan groups will not start until all hosts in the current scan group are finished. If we are performing tasks that are slow or time-consuming, or a host is stuck at the execution of some script, we won't see any results from other hosts in the current group, or others, until the hosts in the current scan group are processed. Reducing the size of a scan group is a good option if you are planning on using Nmap's resume function or if you wish to see results in smaller batches, at the expense of less parallelism in your scans.
The following recipe describes how to adjust the size of the scan groups in Nmap.
How to do it...
Use the --max-hostgroup Nmap argument to set the maximum size for the scan groups. A low number will process results to the screen faster at the expense of less parallelism during the scan:
# nmap -iL list.txt --max-hostgroup 5...
