CompTIA Linux+ (XK0-005) — Question 214

A systems technician is configuring an application server to accept packets from a trusted source with the IP address 192.168.10.22. Which of the following commands will allow communication between the two servers?

Answer options

• A. iptables -L -s 192.168.10.22 -j ACCEPT
• B. iptables -D INPUT -s 192.168.10.22 -j ACCEPT
• C. iptables -A INPUT -s 192.168.10.22 -j ACCEPT
• D. iptables -A OUTPUT -s 192.168.10.22 -j ACCEPT

Correct answer: C

Explanation

The correct command is C, as it appends a rule to the INPUT chain, allowing packets from the specified source IP address. Option A lists rules but does not modify the firewall, while option B deletes an existing rule, and option D incorrectly applies the rule to the OUTPUT chain instead of INPUT.