Ndiff is a tool to aid in the comparison of Nmap scans. It takes two
Nmap XML output files and prints the differences between them. The
differences observed are:
Host states (e.g. up to down)
Port states (e.g. open to closed)
Service versions (from -sV)
OS matches (from -O)
Script output
Ndiff, like the standard diff utility, compares two scans
at a time.
