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#Use your '''centos3''' VM for this part.
<ol>
<li value="2">Use the '''man''' pages to learn about the '''servicesystemctl''' command.</li><li>Issue the following Linux command:
<ul>
<li><b><code><span style="color:#3366CC;font-size:1.2em;">service systemctl list-units -status-all</span></code></b></li>
</ul>
</li>
<li>Note the services that are currently running.</li>
<li>Use the command <b><code><span style="color:#3366CC;font-size:1.2em;">service systemctl stop iptables stop</span></code></b> to stop the service named '''iptables'''</li> <li>Run a the following command to verify that the '''iptables''' service has stopped:<br><b><code><span style="color:#3366CC;font-size:1.2em;">systemctl list-units iptables</span></code></b>.</li><li><br><br>'''NOTE:''' Although the service command seems to work, it is <u>'''deprecated'''</u> (i.e. "out-dated:). It has been replaced by using the [http://zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd#systemd_Command_Usage systemctl] command. This is a command based upon a newer method of starting and managing system services called [http://zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd systemd] (which replaces init - the "initialization table"). This method allows services to run more independently of each other, so that a service may be stopped without other dependent services to be stopped as well.<br><br>The most common '''systemctl''' commands are shown below (it is optional to include the filename extension '''.service''' after the service-name):<ul><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl list-units --all'''</span> (get a listing of all service names. Can pipe to grep to list service you are interested in)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl status service-name'''</span> (Confirm status of a service - running or not-running)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl stop service-name'''</span> (stop a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl start service-name'''</span> (start a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl restart service-name'''</span> (restart a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl enable service-name'''</span> (enable service so service runs upon system startup)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl disable service-name'''</span> (disable service so it does NOT run upon system startup)<br><br></li></ul></li>
<li>If you reboot now - the iptables service will be turned back on. We don't want it on though, it causes students headaches.<br>To turn it off permanently we need to use the '''systemctl''' command:<b><code><span style="color:#3366CC;font-size:1.2em;">systemctl disable iptables</span></code></b><br>(the '''chkconfig''' command used to be the way to enble/disable services, but is now deprecated).</li>
<li>Use the '''systemctl''' command to verify that the '''iptables''' service is no longer running ('''hint:''' issue command, and pipe to grep "'''iptables'''").
