Which syntax scans ports that are in the nmap-services list below a threshold?

Which syntax scans ports that are in the nmap-services list below a threshold?

• A. -p 1-1024
• B. -p [1024]
• C. -p [-1024]
• D. -p 0-1024

Answer: (C)

Understanding port range notation in Nmap helps you target ports by numeric criteria. The question asks for the syntax that scans ports in the nmap-services list that are below a certain threshold. In this context, the form that signals “less than” a value is used. Using a dash before the threshold within brackets communicates that you want all ports below that limit, so -p [-1024] selects ports strictly under 1024. The other options describe ranges that end at 1024, start at 0, or span a consecutive block up to 1024, which don’t express the “below” condition as cleanly.

Understanding port range notation in Nmap helps you target ports by numeric criteria. The question asks for the syntax that scans ports in the nmap-services list that are below a certain threshold. In this context, the form that signals “less than” a value is used. Using a dash before the threshold within brackets communicates that you want all ports below that limit, so -p [-1024] selects ports strictly under 1024. The other options describe ranges that end at 1024, start at 0, or span a consecutive block up to 1024, which don’t express the “below” condition as cleanly.