By default, how many ports does Nmap scan?

• A. 65,535 ports
• B. 10,000 ports
• C. 1,000 ports
• D. 100 ports

Answer: (C)

Nmap balances speed with usefulness by focusing on ports most commonly used in services. By default it scans the 1000 ports that cover the majority of what you’d want to see on a typical host. That default gives a practical snapshot quickly, catching the majority of open services without the overhead of scanning every possible port. If you need deeper coverage, you can extend beyond that default to include more ports or all 65,535 TCP ports, or target a smaller subset like the top 100 or a specific range. Scanning only 100 ports would miss many common services, and scanning all 65,535 would take considerably longer. In short, the default is 1000 ports.