220-1101 Question 69
Single answer443 – Hypertext Transfer Protocol Secure (HTTPS)A technician is troubleshooting a user's issue accessing the company payroll website from a workstation. The user can browse other websites normally, but when entering the payroll site's URL, the browser times out. The technician confirms the payroll server is online and reachable from other devices. Company policy states the payroll application is published as a secure web service only. Which port should the technician verify is allowed through the workstation's local firewall or any filtering software?
- A
21
- B
25
- C
80
- D
443
- E
3389
Show answer and explanation
Correct answer: D
Explanation
HTTPS uses TCP port 443 by default to provide encrypted web communication using TLS. In this scenario, the payroll site is available only as a secure web service, so the technician should verify that port 443 is not being blocked on the workstation or by security software. Port 80 would apply to standard HTTP, but that does not match the requirement for secure access. Common CompTIA A+ troubleshooting expects technicians to know standard well-known ports and apply them in realistic scenarios, such as diagnosing connectivity issues caused by firewall rules. This aligns with standard networking references, including IANA service name and port number assignments and common security best practices that publish sensitive web applications like payroll systems over HTTPS rather than HTTP.
- A. Incorrect.
Option 1 is incorrect. Port 21 is used by FTP for file transfers, not for secure web access to a payroll site. A candidate might choose this if they associate 'server access' generally with file services, but HTTPS traffic does not use FTP.
- B. Incorrect.
Option 2 is incorrect. Port 25 is traditionally used by SMTP for sending email between mail servers. It is unrelated to normal browser access to a secure website. This distractor reflects confusion between common TCP ports used by business applications.
- C. Incorrect.
Option 3 is incorrect. Port 80 is used by HTTP, which is unencrypted web traffic. The scenario specifically states the payroll application is published as a secure web service only, which indicates HTTPS rather than standard HTTP.
- D. Correct.
Option 4 is correct. Port 443 is the default TCP port for HTTPS, which is HTTP secured with TLS/SSL. If a secure website times out while other browsing works, checking whether outbound TCP 443 is blocked by a local firewall, endpoint security product, or content filter is an appropriate troubleshooting step.
- E. Incorrect.
Option 5 is incorrect. Port 3389 is used by Remote Desktop Protocol (RDP), not secure web browsing. Someone might pick this if they are thinking of remote access to a server rather than browser-based access to a web application.