Step2Study
Cisco CCNA (200-301)Network FundamentalsEasy

Which TCP port number is used by default for unencrypted web (HTTP) traffic?

  1. A23
  2. B443
  3. C80
  4. D21
Show answer & explanation

Correct answer: C. 80

Port 80 is the well-known TCP port for standard HTTP traffic. Port 21 is FTP control, port 23 is Telnet, and port 443 is HTTPS (encrypted web traffic).

Why the other options are wrong

  • A. Port 23 is used for unencrypted Telnet sessions.
  • B. Port 443 is used for HTTPS, not plain HTTP.
  • D. Port 21 is used for FTP control connections.

Well-Known Port Numbers

Well-known ports (0-1023) are standardized TCP/UDP port numbers assigned to common protocols and services.

  • HTTP = TCP 80
  • HTTPS = TCP 443
  • FTP = TCP 20/21
  • Telnet = TCP 23

Memory trick: '80 is plain, 443 is locked' for web traffic.

Practice this question Study as flashcard All questions
Previous questionNext question

More Network Fundamentals questions