Exam CFR-310 topic 1 question 16 discussion

A. Execute a scan on a single host, returning only open ports. Explanation: nmap -open 10.10.10.3 performs a scan on the specified IP address (in this case, 10.10.10.3) and returns information only about ports that are open on that host. The -open option ensures that only open ports are displayed, filtering out closed and filtered ports. Why the other answers are incorrect: B. Execute a scan on a subnet, returning detailed information on open ports: The command targets a single host, not a subnet. C. Execute a scan on a subnet, returning all hosts with open ports: The command only scans one host (10.10.10.3), not a range of hosts in a subnet. D. Execute a scan on a single host, returning open services: While Nmap can display services, the -open flag only returns open ports, not detailed service information.

The answer is A, Execute a scan on a single host, returning only open ports. In this case, the command nmap –open 10.10.10.3 will scan the host with IP address 10.10.10.3 and return only the open ports.

https://nmap.org/book/man-briefoptions.html