If the web server supports both HTTP and HTTPS, which ports are used?

• A. 21 and 443
• B. 8080 and 8443
• C. 22 and 443
• D. 80 and 443

Answer: (D)

HTTP and HTTPS have standard default ports. HTTP uses port 80 by default, and HTTPS uses port 443 by default. A web server that supports both typically listens on both ports, so you can access the site via http://domain on port 80 or https://domain on port 443. If a server uses non-default ports, the port must be specified in the URL, such as http://domain:8080 or https://domain:8443. Therefore, the standard pair for a server offering both protocols is 80 and 443.