EX200 Practice Exams

Sample question 1 — Operate running systems

A web application on a RHEL 9 host listens on port 8080, but clients on the corporate network cannot reach it. The administrator has confirmed that the application process is running and wants the firewall to permit that port in the active zone, with the change surviving a reboot of the server. Which command should the administrator run?

1. A. Run firewall-cmd --permanent --add-port=8080/tcp followed by firewall-cmd --reload.
2. B. Run firewall-cmd --add-service=http so the default HTTP port replaces the custom listener.
3. C. Run iptables -F to clear every rule so the application port becomes reachable.
4. D. Run setenforce 0 to relax the host policy so the firewall rule can be applied.

Answer: A. Option A is correct because firewall-cmd --permanent --add-port=8080/tcp records the port in the persistent zone configuration and the following firewall-cmd --reload loads it into the running ruleset. Option B is wrong because the http service maps to port 80, not the 8080 listener this application uses. Option C is wrong because flushing every iptables rule drops all filtering and does not persist a specific allowance. Option D is wrong because SELinux enforcement controls process access, not the packet filter that is blocking the clients.

Sample question 2 — Manage containers

After importing a web storefront container image onto a host, an administrator created a matching systemd unit file under /etc/systemd/system. The service must begin accepting traffic immediately and must also come back automatically after every reboot without anyone logging in. Which single command accomplishes both goals?

1. A. Run systemctl start storefront.service and mask it to keep the service running after boot.
2. B. Run systemctl enable --now storefront.service to start it and register it for future boots.
3. C. Run systemctl reload storefront.service to activate the unit and mark it as persistent.