Which option enables operating system detection in an Nmap scan?

Which option enables operating system detection in an Nmap scan?

• A. -sS
• B. -sO
• C. -O
• D. -A

Answer: (C)

OS detection in Nmap relies on TCP/IP stack fingerprinting to identify the target’s operating system. The dedicated switch to enable this feature is -O. When you run Nmap with -O, it sends a set of probes and analyzes the responses to match them against known OS fingerprints, producing a best guess of the target OS. The aggressive scan option also performs OS detection, but it does more—it combines version detection, script scanning, and traceroute—which makes it broader and slower. The other options serve different purposes: one is a stealth SYN scan, and another is an IP protocol scan, neither of which is focused on identifying the operating system.

OS detection in Nmap relies on TCP/IP stack fingerprinting to identify the target’s operating system. The dedicated switch to enable this feature is -O. When you run Nmap with -O, it sends a set of probes and analyzes the responses to match them against known OS fingerprints, producing a best guess of the target OS. The aggressive scan option also performs OS detection, but it does more—it combines version detection, script scanning, and traceroute—which makes it broader and slower. The other options serve different purposes: one is a stealth SYN scan, and another is an IP protocol scan, neither of which is focused on identifying the operating system.