What is the port number range for well-known ports?

  1. 0-255
  2. 1024-49151
  3. 0-1023 ✓
  4. 49152-65535

Correct answer: 0-1023

Option C is correct because the Internet Assigned Numbers Authority (IANA) defines well-known ports as those in the range 0 through 1023, reserved for common protocols such as HTTP (80), HTTPS (443), FTP (21), SSH (22), and DNS (53). Option A is incorrect because 0 to 255 is not the recognized IANA well-known port range; the well-known range extends up to 1023. Option B is incorrect because 1024 to 49151 defines the registered ports range, used by software vendors for specific applications but not classified as well-known. Option D is incorrect because 49152 to 65535 defines the dynamic or ephemeral ports range, used for temporary client-side connections rather than well-known services.

Topic: · port numbers, iana, well-known ports, networking

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