pfSense

  foreach ($a_maps as $mapent) {

    if (isset($id) && ($a_maps[$id]) && ($a_maps[$id] === $mapent))

      continue;

      /* The fully qualified hostname (hostname + '.' + domainname) must be unique.

        The unqualified hostname does not have to be unique as long as the fully

        qualified hostname is unique. */

    $candidateFqn = "{$_POST['hostname']}.{$_POST['domain']}";

    if ((($existingFqn == $candidateFqn) && $mapent['hostname']) || (($mapent['mac'] == $_POST['mac']) && $mapent['mac']) || (($mapent['ipaddr'] == $_POST['ipaddr']) && $mapent['ipaddr'] ) || (($mapent['cid'] == $_POST['cid']) && $mapent['cid'])) {

      $input_errors[] = gettext("This fully qualified hostname (Hostname + Domainname), IP, MAC address or Client identifier already exists.");

      break;

    }

  }