  <varlistentry>
  <term><emphasis remap='B'>ah</emphasis></term>
  <listitem>
<para>AH authentication algorithm to be used
for the connection, e.g here.
<emphasis remap='B'>hmac-md5</emphasis>
The options must be suitable as a value of
<citerefentry><refentrytitle>ipsec_spi</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
<option>--ah</option>
option.
The default is not to use AH. If for some (invalid) reason you still think you need AH, please
use esp with the null encryption cipher instead. Note also that not all ciphers available to the kernel (eg through CryptoAPI) are necessarilly supported here.
</para>
  </listitem>
  </varlistentry>

