Which of the following protocols uses two different network ports?

Question

Options

• ANTP
• BFTP
• CRsh
• DHTTP
• ETelnet

• B
  73% (16)
• C
  14% (3)
• D
  9% (2)
• E
  5% (1)

Explanation

FTP (File Transfer Protocol) is unique among these options because it uses two separate ports: port 21 for the control channel (sending commands like login credentials and file requests) and port 20 for the data channel (the actual file transfer). This dual-port design is a core part of how FTP operates.

The distractors each use only a single port: NTP (Network Time Protocol) uses UDP port 123, Rsh (Remote Shell) uses TCP port 514, HTTP uses TCP port 80, and Telnet uses TCP port 23.

Memory tip: Think of FTP as needing two "lanes" - one lane to talk (control, port 21) and a separate lane to carry cargo (data, port 20). The number 21 comes first alphabetically/numerically just like a conversation starts before the file moves. No other protocol in this list splits its work across two ports like that.

No community discussion yet for this question.