ddress, then a slash (<code class="literal">/</code>)
       and a <acronym class="acronym">CIDR</acronym> mask length.  The mask
       length indicates the number of high-order bits of the client
       IP address that must match.  Bits to the right of this should
       be zero in the given IP address.
       There must not be any white space between the IP address, the
       <code class="literal">/</code>, and the CIDR mask length.
      </p><p>
       Typical examples of an IPv4 address range specifie