  <varlistentry>
  <term><emphasis remap='B'>rp_filter</emphasis></term>
  <listitem>
<para>This option is obsolete and ignored. Please use the
<emphasis remap='B'>net.ipv4.conf/[iface]/rp_filter&nbsp;=&nbsp;0</emphasis> options
in <filename>/etc/sysctl.conf</filename> instead. This option is badly
documented; it must be <literal>0</literal> in many cases for ipsec
to function.  </para>
  </listitem>
  </varlistentry>
