<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" xmlns:its="http://www.w3.org/2005/11/its" type="topic" style="task" id="net-firewall-on-off" xml:lang="lt">

  <info>
    <link type="guide" xref="net-security" group="#first"/>

    <revision pkgversion="3.4.0" date="2012-02-20" status="final"/>
    <revision pkgversion="3.10" date="2013-11-03" status="incomplete"/>
    <revision pkgversion="3.18" date="2015-09-28" status="final"/>

    <credit type="author">
      <name>Paul W. Frields</name>
      <email>stickster@gmail.com</email>
    </credit>

    <include xmlns="http://www.w3.org/2001/XInclude" href="legal.xml"/>

    <desc>You can control which programs can access the network. This helps to keep your computer secure.</desc>
  </info>

  <title>Enable or block firewall access</title>

  <p>Your system should be equipped with a <em>firewall</em> that allows it to
  block programs from being accessed by other people on the internet or your
  network. This helps to keep your computer secure.</p>

  <p>Many applications can use your network connection. For instance, you can
  share files or let someone view your desktop remotely when connected to a
  network. Depending on how your computer is set up, you may need to adjust the
  firewall to allow these services to work as intended.</p>

  <p>Each program that provides network services uses a specific <em>network
  port</em>. To enable other computers on the network to access a service, you
  may need to “open” its assigned port on the firewall:</p>


  <steps>
    <item>
      <p>Go to <gui>Activities</gui> in the top left corner of the screen and
      start your firewall application. You may need to install a firewall
      manager yourself if you can’t find one (for example, Firestarter or
      GUFW).</p>
    </item>
    <item>
      <p>Open or disable the port for your network service, depending on
      whether you want people to be able to access it or not. Which port you
      need to change will <link xref="net-firewall-ports">depend on the
      service</link>.</p>
    </item>
    <item>
      <p>Save or apply the changes, following any additional instructions given
      by the firewall tool.</p>
    </item>
  </steps>

</page>
