CompTIA Linux+ (XK0-005) — Question 50

A Linux systems administrator needs to persistently enable IPv4 forwarding in one of the Linux systems. Which of the following commands can be used together to accomplish this task? (Choose two.)

Answer options

• A. sysctl net.ipv4.ip_forward
• B. sysctl -w net.ipv4.ip_forward=1
• C. echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
• D. echo 1 > /proc/sys/net/ipv4/ip_forward
• E. sysctl –p
• F. echo "net.ipv6.conf.all.forwarding=l" >> /etc/sysctl.conf

Correct answer: B, C

Explanation

The correct answers are B and C because B sets the IPv4 forwarding value in the current session, while C adds the setting to the sysctl configuration file for persistence across reboots. Options A and D do not modify the configuration persistently, and E is used to apply changes from the configuration file, not to set them. Option F pertains to IPv6 and is irrelevant for enabling IPv4 forwarding.