Approximately how many services are defined in the NMAP service file?

• A. 1000
• B. 1500
• C. 3000
• D. more than 2200

Answer: (D)

Nmap relies on a large service database to translate port numbers into likely service names during scans. This nmap-services file isn’t limited to just the well-known ports; it grows to include many less common, historical, and alias entries as the project updates it. Because of that continual expansion, the total number of defined services is well beyond the 2000 mark. In recent versions you’ll see roughly a couple thousand entries, typically more than 2200. That’s why the option indicating more than 2200 is the best fit. This matters because a richer service list improves the accuracy of port-to-service name mappings during scans, whereas a smaller list could leave some ports unnamed or generically labeled.