The system cannot resolve the hostname because no DNS servers are configured, as indicated by the absence of nameserver entries in the resolver configuration file, even though network connectivity and routing are present.

Using tee allows output to be viewed in real time on the terminal while simultaneously writing it to logfile.txt. This meets both requirements: monitoring live updates and saving them for later review.

This command displays kernel ring buffer messages, which include hardware-related events such as device initialization and USB device connections.

The chage command is used to manage password aging policies, and setting the maximum password age to 90 days enforces the required password change interval for user accounts.

The log shows avc: denied { read } caused by SELinux when sshd tries to access authorized_keys. The file has the wrong SELinux context (unconfined_u:object_r:home_root_t) instead of the expected context for SSH. This mismatch blocks SSH key authentication even though file permissions are correct. Adjusting the SELinux context (e.g., with restorecon) resolves the issue.