man: update sysctl example about netfilter

It turns out that since kernel 3.18 netfilter on bridged packets
is off anyway, so the example should be reworded (and the module
name updated).

1 files changed, 17 insertions, 4 deletions

diff --git a/man/sysctl.d.xml b/man/sysctl.d.xml
index 8a131791a5..e5b2bc0ac9 100644
--- a/man/sysctl.d.xml
+++ b/man/sysctl.d.xml
@@ -123,11 +123,12 @@
     </example>
 
     <example>
-      <title>Disable packet filter on bridged packets (method one)</title>
+      <title>Apply settings available only when a certain module is loaded (method one)</title>
       <para><filename>/etc/udev/rules.d/99-bridge.rules</filename>:
       </para>
 
-      <programlisting>ACTION=="add", SUBSYSTEM=="module", KERNEL=="bridge", RUN+="/usr/lib/systemd/systemd-sysctl --prefix=/net/bridge"
+      <programlisting>ACTION=="add", SUBSYSTEM=="module", KERNEL=="br_netfilter", \
+      RUN+="/usr/lib/systemd/systemd-sysctl --prefix=/net/bridge"
 </programlisting>
 
       <para><filename>/etc/sysctl.d/bridge.conf</filename>:
@@ -137,14 +138,20 @@
 net.bridge.bridge-nf-call-iptables = 0
 net.bridge.bridge-nf-call-arptables = 0
 </programlisting>
+
+      <para>This method applies settings when the module is
+      loaded. Please note that unless the <filename>br_netfilter</filename>
+      module is loaded, bridged packets will not be filtered by
+      netfilter (starting with kernel 3.18), so simply not loading the
+      module is suffient to avoid filtering.</para>
     </example>
 
     <example>
-      <title>Disable packet filter on bridged packets (method two)</title>
+      <title>Apply settings available only when a certain module is loaded (method two)</title>
       <para><filename>/etc/modules-load.d/bridge.conf</filename>:
       </para>
 
-      <programlisting>bridge</programlisting>
+      <programlisting>br_netfilter</programlisting>
 
       <para><filename>/etc/sysctl.d/bridge.conf</filename>:
       </para>
@@ -153,6 +160,12 @@ net.bridge.bridge-nf-call-arptables = 0
 net.bridge.bridge-nf-call-iptables = 0
 net.bridge.bridge-nf-call-arptables = 0
 </programlisting>
+
+      <para>This method forces the module to be always loaded. Please
+      note that unless the <filename>br_netfilter</filename> module is
+      loaded, bridged packets will not be filtered with netfilter
+      (starting with kernel 3.18), so simply not loading the module is
+      suffient to avoid filtering.</para>
     </example>
   </refsect1>