shorewall_code/manpages6/shorewall6-nesting.xml

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<refentry>
  <refmeta>
    <refentrytitle>shorewall6-nesting</refentrytitle>

    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>nesting</refname>

    <refpurpose>shorewall6 Nested Zones</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <arg choice="plain"
      rep="norepeat"><replaceable>child-zone</replaceable>[:<replaceable>parent-zone</replaceable>[,<replaceable>parent-zone</replaceable>]...]</arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>In <ulink url="shorewall-zones.html">shorewall6-zones</ulink>(5), a
    zone may be declared to be a sub-zone of one or more other zones using the
    above syntax.</para>

    <para>Where zones are nested, the CONTINUE policy in <ulink
    url="shorewall6-policy.html">shorewall6-policy</ulink>(5) allows hosts
    that are within multiple zones to be managed under the rules of all of
    these zones.</para>
  </refsect1>

  <refsect1>
    <title>Example</title>

    <para><filename>/etc/shorewall6/zones</filename>:</para>

    <programlisting>        #ZONE    TYPE        OPTION
        fw       firewall
        net      ipv6
        sam:net  ipv6
        loc      ipv6</programlisting>

    <para><filename>/etc/shorewall6/interfaces</filename>:</para>

    <programlisting>        #ZONE     INTERFACE     BROADCAST     OPTIONS
        -         eth0          detect        blacklist
        loc       eth1          detect</programlisting>

    <para><filename>/etc/shorewall6/hosts</filename>:</para>

    <programlisting>        #ZONE     HOST(S)                     OPTIONS
        net       eth0:[::\]
        sam       eth0:[2001:19f0:feee::dead:beef:cafe]</programlisting>

    <para><filename>/etc/shorewall6/policy</filename>:</para>

    <programlisting>        #SOURCE      DEST        POLICY       LOG LEVEL
        loc          net         ACCEPT
        sam          all         CONTINUE
        net          all         DROP         info
        all          all         REJECT       info</programlisting>

    <para>The second entry above says that when Sam is the client, connection
    requests should first be processed under rules where the source zone is
    sam and if there is no match then the connection request should be treated
    under rules where the source zone is net. It is important that this policy
    be listed BEFORE the next policy (net to all). You can have this policy
    generated for you automatically by using the IMPLICIT_CONTINUE option in
    <ulink url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>

    <para>Partial <filename>/etc/shorewall6/rules</filename>:</para>

    <programlisting>        #ACTION   SOURCE    DEST                  PROTO    DEST PORT(S)
        ...
        ACCEPT    sam       loc:2001:19f0:feee::3 tcp      ssh
        ACCEPT    net       loc:2001:19f0:feee::5 tcp      www
        ...</programlisting>

    <para>Given these two rules, Sam can connect with ssh to
    2001:19f0:feee::3. Like all hosts in the net zone, Sam can connect to TCP
    port 80 on 2001:19f0:feee::5. The order of the rules is not
    significant.</para>
  </refsect1>

  <refsect1 id="Virtual">
    <title>Virtual Zones</title>

    <para>Beginning with Shorewall 4.4.5, Shorewall allows the declaration of
    <firstterm>virtual</firstterm> zones. A virtual zone has no definition in
    <filename>/etc/shorewall6/interfaces</filename> or in
    <filename>/etc/shorewall6/hosts</filename>. Rather, it is used as a parent
    zone for other zones in <filename>/etc/shorewall6/zones</filename>.</para>

    <para>Example:</para>

    <para><filename>/etc/shorewall6/zones</filename>:</para>

    <programlisting>        #ZONE            TYPE          OPTIONS
        fw               firewall
        net              ipv6
        loc              virtual       #Virtual Zone
        loc1:loc         ipv6
        loc2:loc         ipv6</programlisting>

    <para><filename>/etc/shorewall/interfaces</filename>:</para>

    <programlisting>        #ZONE   INTERFACE       BROADCAST       OPTIONS
        net     eth0            detect          dhcp,tcpflags
        -       eth1            detect          tcpflags</programlisting>

    <para><filename>/etc/shorewall/hosts</filename>:</para>

    <programlisting>        #ZONE   HOST(S)                         OPTIONS
        loc1    eth1:2001:19f0:feee:1::/48
        loc2    eth1:2001:19f0:feee:2::/48</programlisting>

    <para>There are several restrictions on virtual zones:</para>

    <itemizedlist>
      <listitem>
        <para>A maximum of four virtual zones may be defined.</para>
      </listitem>

      <listitem>
        <para>They should not be used with IMPLICIT_CONTINUE=Yes in <ulink
        url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
      </listitem>
    </itemizedlist>

    <para>When a connection request to/from a sub-zone of a virtual zone does
    not match the rules for the sub-zone, the connection is compared against
    the rules (and policies) for the parent virtual zone.</para>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <para>/etc/shorewall6/zones</para>

    <para>/etc/shorewall6/interfaces</para>

    <para>/etc/shorewall6/hosts</para>

    <para>/etc/shorewall6/policy</para>

    <para>/etc/shorewall6/rules</para>
  </refsect1>

  <refsect1>
    <title>See ALSO</title>

    <para>shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5),
    shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5),
    shorewall6-maclist(5), shorewall6-params(5), shorewall6-policy(5),
    shorewall6-providers(5), shorewall6-route_rules(5),
    shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5),
    shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5),
    shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)</para>
  </refsect1>
</refentry>