Which option disables host discovery, performing a port scan only?

• A. -Pn
• B. -P0
• C. -f
• D. -v

Answer: (A)

Disabling host discovery means skipping the step where Nmap checks whether targets are alive before scanning. The option -Pn tells Nmap to skip that host discovery phase and go straight into a port scan on all specified targets, assuming they’re online. This is useful when ping probes are blocked by firewalls or you want to avoid discovery traffic, and it can make scans faster or more reliable in such environments. The scan proceeds to probe ports on each target regardless of whether Nmap could confirm they’re up, returning open, closed, or filtered ports as usual. In older versions, -P0 served a similar purpose, but -Pn is the current, preferred switch for this behavior.