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?

An administrator recently updated the BIND software package and would like to review the default configuration that shipped with this version. Which of the following files should the administrator review?

A Linux engineer receives reports that files created within a certain group are being modified by users who are not group members. The engineer wants to reconfigure the server so that only file owners and group members can modify new files by default. Which of the following commands would accomplish this task?

Which of the following data structures is written in JSON?
A)

B)

C)

D)

A cloud engineer needs to check the link status of a network interface named eth1 in a Linux server. Which of the following commands can help to achieve the goal?