N10-009 Question 73
Single answerHTTPS: 443A company hosts a customer portal on a web server in a DMZ. Users report that they can reach the site with http://portal.example.com, but https://portal.example.com times out from both the internal network and the internet. A network administrator confirms DNS resolution is correct and the web server is online. The security policy requires encrypted web access without changing the application itself. Which action is the MOST appropriate to restore secure access?
- A
Allow inbound TCP port 443 to the web server through the firewall
- B
Allow inbound UDP port 443 to the web server through the firewall
- C
Allow inbound TCP port 22 to the web server through the firewall
- D
Allow inbound TCP port 80 to the web server through the firewall
Show answer and explanation
Correct answer: A
Explanation
The key issue is that the site works over HTTP but fails over HTTPS, which strongly suggests that secure web traffic is not being allowed or serviced on the expected port. In Network+ objectives, HTTPS is associated with TCP port 443 and is used to secure web sessions with TLS. The most appropriate corrective action is to allow inbound TCP 443 through the firewall to the web server, assuming the server is configured with a valid certificate and HTTPS listener. Port 80 is for unencrypted HTTP, port 22 is for SSH, and UDP 443 is not the standard answer for HTTPS service identification in foundational networking contexts. This aligns with common firewall best practices of permitting only the specific required service ports and with standard service-port mappings documented by IANA and vendor firewall guidance.
- A. Correct.
Correct. HTTPS uses TCP port 443 for encrypted web traffic using TLS. Since HTTP access already works, the server is reachable on port 80, but secure access is failing. Opening or permitting inbound TCP 443 to the web server is the most appropriate action to restore HTTPS connectivity while meeting the requirement for encrypted access.
- B. Incorrect.
Incorrect. Traditional HTTPS for web browsing uses TCP, not UDP, on port 443. A candidate might choose this option because some modern protocols such as HTTP/3 use QUIC over UDP 443, but standard HTTPS service availability on Network+ is associated with TCP 443, and the most appropriate firewall rule for restoring typical secure web access is TCP 443.
- C. Incorrect.
Incorrect. TCP port 22 is used for SSH remote administration, not for HTTPS client access. This distractor targets the misconception that any secure protocol can satisfy an encrypted web requirement. Enabling SSH would not allow users to access the website securely in a browser.
- D. Incorrect.
Incorrect. TCP port 80 is used for HTTP, which is already functioning according to the scenario. Opening port 80 does not provide encryption and does not meet the stated security policy requirement for secure web access.