A systems administrator is receiving tickets from users who cannot reach the application app that should be listening on port 9443/tcp on a Linux server.
To troubleshoot the issue, the systems administrator runs netstat and receives the following output:

Based on the information above, which of the following is causing the issue?

A. The IP address 0.0.0.0 is not valid.
B. The application is listening on the loopback interface.
C. The application is listening on port 1234.
D. The application is not running.

A development team asks an engineer to guarantee the persistency of journal log files across system reboots.
Which of the following commands would accomplish this task?

A. grep -i auto /etc/systemd/journald.conf && systemctl restart systemd- journald.service
B. cat /etc/systemd/journald.conf | awk '(print $1,$3)'
C. sed -i 's/auto/persistent/g' /etc/systemd/journald.conf && sed -i 'persistent/ s/^#//q' /etc/systemd/journald.conf
D. journalctl –list-boots && systemctl restart systemd-journald.service

Which of the following technologies provides load balancing, encryption, and observability in containerized environments?

A. Virtual private network
B. Sidecar pod
C. Overlay network
D. Service mesh

A systems administrator received a notification that a system is performing slowly. When running the top command, the systems administrator can see the following values:

Which of the following commands will the administrator most likely run NEXT?

A. vmstat
B. strace
C. htop
D. lsof

A systems administrator pressed Ctrl+Z after starting a program using the command line, and the shell prompt was presented. In order to go back to the program, which of the following commands can the administrator use?

A. fg
B. su
C. bg
D. ed

A Linux administrator is alerted to a storage capacity issue on a server without a specific mount point or directory. Which of the following commands would be MOST helpful for troubleshooting? (Choose two.)

A. parted
B. df
C. mount
D. du
E. fdisk
F. dd
G. ls

A Linux systems administrator is configuring a new filesystem that needs the capability to be mounted persistently across reboots. Which of the following commands will accomplish this task? (Choose two.)

A. df -h /data
B. mkfs.ext4 /dev/sdc1
C. fsck /dev/sdc1
D. fdisk -l /dev/sdc1
E. echo "/data /dev/sdc1 ext4 defaults 0 0" >> /etc/fstab
F. echo "/dev/sdc1 /data ext4 defaults 0 0" >> /etc/fstab

A cloud engineer needs to block the IP address 192.168.10.50 from accessing a Linux server. Which of the following commands will achieve this goal?

A. iptables -F INPUT -j 192.168.10.50 -m DROP
B. iptables -A INPUT -s 192.168.10.30 -j DROP
C. iptables -i INPUT –ipv4 192.168.10.50 -z DROP
D. iptables -j INPUT 192.168.10.50 -p DROP

A server is experiencing intermittent connection issues. Some connections to the Internet work as intended, but some fail as if there is no connectivity. The systems administrator inspects the server configuration:

Which of the following is MOST likely the cause of the issue?

A. An internal-only DNS server is configured.
B. The IP netmask is wrong for ens3.
C. Two default routes are configured.
D. The ARP table contains incorrect entries.

A Linux administrator needs to determine whether a hostname is in the DNS. Which of the following would supply the information that is needed?

A. nslookup
B. rsyn
C. netstat
D. host