Question
Which of the following port numbers is used for a file transfer?
- A. 21 Correct
- B. 53
- C. 68
- D. 389
Explanation
FTP (File Transfer Protocol) uses TCP port 21 for its control connection, with port 20 as its default data port in active mode. Port 53 is DNS, port 68 is the DHCP client port, and port 389 is LDAP. None of those three is used to transfer files.
