  <varlistentry>
  <term><emphasis remap='B'>interfaces</emphasis></term>
  <listitem>
<para>virtual and physical interfaces for IPsec to use:
a single
<emphasis remap='I'>virtual</emphasis><emphasis remap='B'>=</emphasis><emphasis remap='I'>physical</emphasis> pair, a (quoted!) list of pairs separated
by white space, or
<emphasis remap='B'>%none</emphasis>.
One of the pairs may be written as
<emphasis remap='B'>%defaultroute</emphasis>,
which means: find the interface <emphasis remap='I'>d</emphasis> that the default route points to,
and then act as if the value was ``<emphasis remap='B'>ipsec0=</emphasis><emphasis remap='I'>d</emphasis>''.
<emphasis remap='B'>%defaultroute</emphasis>
is the default;
<emphasis remap='B'>%none</emphasis>
must be used to denote no interfaces, or when using the NETKEY stack.
If
<emphasis remap='B'>%defaultroute</emphasis>
is used (implicitly or explicitly)
information about the default route and its interface is noted for
use by
<citerefentry><refentrytitle>ipsec_auto</refentrytitle><manvolnum>8</manvolnum></citerefentry>.)</para>
  </listitem>
  </varlistentry>
