Which syntax scans ports by protocol name such as http and ftp?

Which syntax scans ports by protocol name such as http and ftp?

• A. -p 80,443
• B. -p 6,17
• C. -p http
• D. -p http,ftp

Answer: (D)

The concept being tested is that Nmap can interpret service names, not just numbers, via the -p option. When you specify a service name like http or ftp, Nmap looks up the standard port associated with that service (http maps to 80, ftp to 21) and scans those ports. Using both in one command, -p http,ftp, tells Nmap to scan the two well-known ports for those services in one go, covering both HTTP and FTP ports. The other options rely on numeric ports or on a single service name, so they don’t scan both services together or they scan ports that aren’t implied by service names.

The concept being tested is that Nmap can interpret service names, not just numbers, via the -p option. When you specify a service name like http or ftp, Nmap looks up the standard port associated with that service (http maps to 80, ftp to 21) and scans those ports. Using both in one command, -p http,ftp, tells Nmap to scan the two well-known ports for those services in one go, covering both HTTP and FTP ports. The other options rely on numeric ports or on a single service name, so they don’t scan both services together or they scan ports that aren’t implied by service names.