CompTIA Linux+ (XK0-004) — Question 100

A systems administrator needs to allow the Linux server to receive HTTP connections from Internet hosts. By default, the port for HTTP connections is blocked.
Which of the following rules should be added in the firewall to allow this type of connection?

Answer options

• A. firewall-cmd --zone=public --add-port=443/tcp --permanent
• B. firewall-cmd --zone=internal --add-port=80/tcp --permanent
• C. firewall-cmd --zone=public --add-port=80/tcp --permanent
• D. firewall-cmd --zone=internal --add-port=443/tcp --permanent

Correct answer: C

Explanation

The correct answer is C because it opens port 80, which is the standard port for HTTP traffic, in the public zone. Option A is incorrect as it opens port 443, which is used for HTTPS, not HTTP. Option B is wrong because it attempts to open port 80 in the internal zone, which does not allow external HTTP connections. Option D similarly opens port 443 in the internal zone and is not relevant for HTTP.