  <varlistentry>
  <term><emphasis remap='B'>forceencaps</emphasis></term>
  <listitem>
<para>
In some cases, for example when ESP packets are filtered or when a broken
IPsec peer does not properly recognise NAT, it can be useful to force
RFC-3948 encapsulation.
<emphasis remap='B'>forceencaps=yes</emphasis> forces the NAT detection
code to lie and tell the remote peer that RFC-3948 encapsulation (ESP in UDP
port 4500 packets) is required. For this option to have any effect, the setup section option
<emphasis remap='B'>nat_traversal=yes</emphasis> needs to be set.
Acceptable values are <emphasis remap='B'>yes</emphasis> or <emphasis remap='B'>no</emphasis>
(the default).
</para>
  </listitem>
  </varlistentry>

