100-150 Question 264
Single answerA company has deployed a firewall to secure its network. The firewall is configured to allow HTTP (port 80) and HTTPS (port 443) traffic to a web server but block all other incoming traffic. A team member reports that they cannot access the web server using FTP (port 21). What is the most likely reason for this issue?
- A
The firewall does not have a rule allowing FTP traffic to the web server.
- B
The firewall is malfunctioning and dropping all incoming traffic.
- C
The web server is not configured to respond to FTP requests.
- D
The firewall allows FTP traffic only if encrypted.
Show answer and explanation
Correct answer: A
Explanation
Firewalls operate by filtering traffic based on configured rules, such as allowed or blocked ports, protocols, or IP addresses. In this scenario, the firewall is configured to allow only HTTP and HTTPS traffic to the web server. Since FTP traffic (port 21) is not explicitly allowed, the firewall blocks it, which is the most likely cause of the issue.
- A. Correct.
Firewalls filter traffic based on rules such as allowed or blocked ports. Since FTP (port 21) is not explicitly allowed in the firewall's configuration, it is being blocked.
- B. Incorrect.
If the firewall were malfunctioning, it would likely drop all traffic, not just FTP traffic. However, HTTP and HTTPS traffic are functioning correctly.
- C. Incorrect.
While the web server might not support FTP, the issue described is specifically about the firewall blocking traffic, not the server configuration.
- D. Incorrect.
Firewalls do not automatically filter traffic based on encryption unless explicitly configured to do so. This is not relevant to the described scenario.