Which of the following is the reason the firewall rules are not active?

A systems administrator configured firewall rules using firewalld.

However, after the system is rebooted, the firewall rules are not present:

The systems administrator makes additional checks:

Which of the following is the reason the firewall rules are not active?
A . iptables is conflicting with firewalld.
B . The wrong system target is activated.
C . FIREWALL_ARGS has no value assigned.
D . The firewalld service is not enabled.

View Answer

Answer: D

Explanation:

The reason the firewall rules are not active is that the firewalld service is not enabled. This means that the service will not start automatically at boot time or after a system reload. To enable the firewalld service, the systems administrator needs to use the command sudo systemct1 enable firewalld. This will create a symbolic link from the firewalld service file to the appropriate systemd target, such as multi-user.target. Enabling the service does not start it immediately, so the systems administrator also needs to use the command sudo systemct1 start firewalld or sudo systemct1 reload firewalld to activate the firewall rules.

The other options are not correct reasons for the firewall rules not being active. iptables is not conflicting with firewalld, because firewalld uses iptables as its backend by default. The wrong system target is not activated, because firewalld is independent of the system target and can be enabled for any target. FIREWALL_ARGS has no value assigned, but this is not a problem, because FIREWALL_ARGS is an optional environment variable that can be used to pass additional arguments to the firewalld daemon, such as –debug or –nofork. If FIREWALL_ARGS is empty or not defined, firewalld will use its default

arguments.

References: firewalld.service(8) – Linux manual page; firewall-cmd(1) – Linux manual page; systemct1(1) – Linux manual page